Frequently Asked Questions (FAQ)
1. How to access Webcast?
2. Can you send forecasts to a DeLorme InReach ?
3. SSB Nets schedule / coverage
4. Our Services
5. Notes
6. Support Request, by email or website
7. Support Requests - more info
8. Unable to Transmit on SSB? That's OK, I can broadcast your forecast!
9. Why is your forecast different from forecasts from other sources?
10. What areas are covered in Regional Daily Email forecasts?
11. What is the "<" symbol in my email forecast
12. What is "N ROUTE" and "S ROUTE" in my email forecast?
13. Regional Daily Email forecast Primer
14. Regional Daily Email forecast Primer
15. Regional Daily Email forecast Primer
16. I have stopped receiving email forecasts, even though my subscription is current
17. What methods of payment are accepted?
18. I'm not getting email forecasts I signed-up for.
19. Is your website secure?
20. How can I receive my forecast?
21. Can you email me a copy of an old forecast / forecast for a previous day?
22. Custom (vessel-specific) forecasts by Email
23. I'm on a long passage. How much will Custom (vessel-specific) email forecasts cost?
24. I want a Custom forecast by email. How do you decide when to send the forecast?
25. What if weather is no good?
26. How do I order another forecast?
27. Will you monitor the weather and contact us if things change?
28. I'm on passage, and want a forecast emailed to me each day, can you do that?
29. How often should I request a new Custom Email forecast?
30. Can you give me a waypoint to head toward?
31. Sharing forecasts with others
32. Position Reports
33. Do you provide service for vessels Crossing the Atlantic?
34. How do I use your service on my upcoming ocean voyage?
35. How do I use your service for Cruising the US E Coast and Bahamas/Caribbean?
36. I purchased a package of 10 pre-paid forecasts. How do I get a forecast?
37. Pacific Ocean - do you provide forecasts, or know someone who does?
38. Is your book, Coastal & Offshore Weather, the Essential Handbook, available as an E-Book?
39. Evening SSB Nets?
40. DeLorme InReach / Garmin Explorer?
41. Typical seasonal weather in E Caribbean
42. Crossing Atlantic
43. Hurricane Season 2020 options
44. InReach
45. After arrival
46. Definitions: TROF, RIDGE
47. Concerned about Tropical LO pressure systems in the Caribbean, Bahamas, or elsewhere?

48. InReach for SDR
49. SDSA Wx Info "Push / Pull"
50. DECCA Channel
51. Example of Custom forecast Transatlantic



1. How to access Webcast?
UPDATED Wednesday September 3, 2020:
You can participate in interactive, real-time SSB Voice Nets from almost any Internet-connected device.

Login to your account here:

https://mwxc.com/client_login.php

With your username & password

Once logged-in to your account at mwxc.com, click one of the 2 "WEBCAST" links in the upper-right area of the screen.

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"HIGH BANDWIDTH" Webcasts stream:
--my Computer Desktop (you can see the weather details I'm describing)
--my voice & Webcam, and SSB Net audio
--allows you to text questions

To ENTER:
Type "Your Name" and "E-mail", then press ENTER

If accessing from a phone / tablet, then once you have "MeetinGo" app installed (link in the iOS App Store: https://apps.apple.com/us/app/meetingo/id627558546) it may be easiest to enter Webcasts in the future by launching the app and entering the 9-digit meeting room code 728694742.

Make sure you have updated your iOS operating system, and when the "MeetinGo" app launches it should be Version 4.1.0 (version is under Settings < General < iPhone Storage < MeetinGo)

Phone-in option:
Phone-in participant dial 646-982-0240
PIN = 422119#
Microphone is set to ON by default, please press *1 to MUTE your microphone.
When you hear us taking questions from Webcast participants, you may press *1 again to toggle to enable your microphone. Please toggle OFF your mic with *1 when you are finished receiving your forecast.


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"LOW-BANDWIDTH" Webcasts stream:
--my voice and SSB Net audio
--allows you to text questions

To ENTER:
Type "Your Name" and "E-mail", then press ENTER

If accessing from a phone / tablet, then once you have "MeetinGo" app installed (link in the iOS App Store: https://apps.apple.com/us/app/meetingo/id627558546) it may be easiest to enter Webcasts in the future by launching the app and entering the 9-digit meeting room code 824914889.

Make sure you have updated your iOS operating system, and when the "MeetinGo" app launches it should be Version 4.1.0 (version is under Settings < General < iPhone Storage < MeetinGo)

Phone-in participant dial 646-982-0240
PIN = 744482#
Your microphone is disabled permanently. To ask a question, verbally, dial into the High-bandwidth Webcast.
2. Can you send forecasts to a DeLorme InReach ?
YES!
Simply message us from your DeLorme InReach / Garmin Explorer to:

chris@mwxc.com

and include your:
1. location, course, speed (location should be inserted automatically by InReach, but this does not always happen)
2. wind/sea conditions
3. ask a question, so we can provide the most useful information to aid your decision making

We'll text back your answer/forecast.

Forecasts are $30 each, or $250 for a package of 10, good for 1 year.

You can sign-up by clicking any of the orange "sign-up" links on the website www.mwxc.com then selecting a single phone-in forecast ($30) or a package of (10) for $250. You can use these forecasts by phone or InReach (mix-and-match).
3. SSB Nets schedule / coverage
https://www.mwxc.com/marine_weather_services.php
4. Our Services
We provide high-value-added weather forecasts and routing advice, typically to small sail and power vessels, via SSB Voice Nets, voice telephone, email, SMS text messaging, or any combination.

We cover not only the Caribbean and Bahamas, but US E Coast, Gulf Of Mexico, and the entire Atlantic (Canadian Maritimes, Bermuda, Azores, Canaries, to/from Europe), and in the Pacific we focus on SanDiego-Mexico-C America-Ecuador-Galapagos-Marquesas.

Services:
SSB Nets $199/yr or $99/mo, includes unlimited Daily contact, as often as 6 Days/week. You hail me when you want a forecast and routing advice, there is no daily check-in requirement. This is a custom forecast, just for you, and we can discuss weather and routing as much as you wish. Includes simultaneous interactive Internet Webcasts and recorded forecasts.

Regional Daily Email forecasts $199/yr, $99 for 3 mo, $55/mo, is a regional forecast including travel suggestions and should give you the information you need to make good decisions when moving along the Islands. Is NOT geared for offshore passagemaking (away from the Islands / US Coast), and does NOT include vessel-specific forecasts.

BOTH of the above $299/yr or $129/mo

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Custom (vessel-specific forecasts and routing advice): The SSB Nets above are also Custom forecasts. Custom forecasts via voice telephone, SMS message, or Email are as follows:

Best deal is 10 prepaid forecast credits for $250 may be used as follows (but you may purchase individual forecasts):

phone-in or SMS message ($30/call or 1 forecast credit)
email Detailed 5-day forecast ($65 or 2 forecast credits)
email Detailed 2-day forecast ($35 or 1 forecast credit)
email General 10-day Outlook ($35 or 1 forecast credit)

To purchase any of the above: visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form. Your order will process in real time and you will receive an automated confirmation email. If not, please call 863-248-2702 to place or troubleshoot your order.
5. Notes
Each time I have contact with a client, I make a NOTE in the database. I can elect to email that NOTE to all email addresses you have selected to receive emails/notes/support.

This works well to email you a brief note if I think you have not copied me well on the SSB Voice Nets, or if you have family back home wanting to know where you are, etc.

If you want me to email NOTEs every time I make one, please let me know (they'd be emailed to all addresses set to receive email/notes/support).
6. Support Request, by email or website
When you email me at support@mwxc.com my system searches the database for client records matching your email address, then tells me when I need to answer your email.

IMPORTANT: the email address in the "From" or "Reply-To" fields of your support request should match an email address in your client record at mwxc.com (questions from existing clients are given priority, and if the system can't match From/Reply-to to your client record, it will assume you are not a client).

The Subject Line of your Support Request MUST contain 3 items (4th is optional):

1. Priority (H, M, L) corresponding to high (you must have an answer) / medium (you would really appreciate an answer) / low (I should answer you only if I have ample time).

2. Date, for example: 05-Dec-2011
Format of date can be:
US standard DD/MM/YY or YYYY (for example 12/5/11)
my preferred format above DD-Month-YY or YYYY (05-Dec-2011)
or even Month DD, YY or YYYY (Dec 5, 2011)

3. Time, in even hours EST/EDT for example: 1700 (1700 hrs EST/EDT)

4. (Optional but suggested) brief text subject, for example: when should I tack

Each item should be separated by a comma. So, the subject line for the above request would look like this:

H, 12/5/11, 1700, when should I tack

NOTE: Weather-related questions should be answered as late as possible, so I can base my answer on the best possible information - while still giving you time to retrieve my answer and incorporate my answer into your plans.

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When you follow the above protocol, here's what happens:
--Your support request appears on my computer, in the proper order so I have the best chance to answer all support requests from existing clients in a timely manner.
--All interactions I have with you, including this support request, are contained in your client record, so I have all your information whenever we interact.
--I provide you with the best possible answer to your question at the optimum time.

Follow-up questions:
If you send a follow-up Support Request, you may remove the old message body (to reduce email size). Within the subject line, you may adjust Priority, Date, Time...but do NOT alter or remove the xxxxx-xxxxx Support Ticket number.

If you have Internet access, you can login to your account at mwxc.com then enter your Support Request from your Client Panel or the Contact page - these are handled in the same manner as email requests.

You can still use the chris@mwxc.com email address for general correspondence, but if you require an answer, I will get you that answer better and faster if you email questions to: support@mwxc.com

When I am on vacation and Ed Bilicki fills in for me, Ed will receive and respond to Support Requests sent to support@mwxc.com (and entered on the website) just as I do.
7. Support Requests - more info
Support Requests emailed to support@mwxc.com are the BEST way for all clients to get useful and timely answers from me on both weather-related and account-related questions.

We've fine-tuned the Support Request feature, as follows:

Requests submitted WITHOUT suggested SUBJECT LINE are now treated as requiring an answer immediately. Previously, they were treated as non-critical requests.

Further discussion...
For best service, please include the following in the SUBJECT LINE of your email to support@mwxc.com :

Priority (H, M, L for high, medium, low), Date-answer-required (any date format you like, but note xx/xx/xxxx will be read as mm/dd/yyyy), Time-answer-required (in hours EST), Subject

Each separated by a COMMA...for instance:

H, 1/14/2012, 1600, when should I cross Anegada Passage

The above request will be treated as critical (High priority), and I'll make every effort to answer it no later than Jan 14, 2012 at 1600 hours EST.

By including the above in your SUBJECT LINE, I will be able to get you the best possible answer at the most-appropriate time.

If you do NOT include the above information in your SUBJECT LINE, then I will have to guess when I should respond.

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When replying to (or re-opening) a Support Request, please enter your reply text BELOW the appropriate line...

OR

DELETE ALL of the message body except for the new text you're sending.

If you simply add your text to the BEGINNING of the email, my system will NOT display the text for me.

I hope the Support Request feature, and other current (and planned) features make Marine Weather Center an even-more-valuable resource when you're Cruising. Thank you for your continuing support!...Chris.
8. Unable to Transmit on SSB? That's OK, I can broadcast your forecast!
If you're unable to transmit on SSB (or I'm consistently unable to hear you when you do), we can still transmit your forecast on the SSB Voice Nets (usually right after the Synopsis), if you do the following:

Email

support@mwxc.com

1. Your email should have the following in the SUBJECT LINE:

H, 1/25/2012, 0600, Transmit forecast on SSB Net

Where H is the priority (high)
1/25/2012 is the date you want me to BEGIN broadcasting the forecast
0600 is the time (important that it's 0600 so I see it 1st thing in the morning)
Transmit forecast on SSB Net tells me what you need

2. in the MESSAGE BODY your:

a. vessel name
b. location
c. Plan (i.e. where you're going, when, and anything else I should know)
d. the SSB Net on which you'd like me to broadcast your forecast

Alternatively, you can ask another vessel to hail me with the above information, or you can call me ahead of time with the above information, at 863-248-2702, and I'll broadcast your forecast as requested.

It's best if you update the above information as frequently as possible, by any means possible.
If I'm broadcasting your forecast over a number of days, please close-the-loop by telling me when I can stop broadcasting your forecast.
9. Why is your forecast different from forecasts from other sources?
I employ a unique methodology, which I call the "worst likely scenario". When preparing your forecast, I consider what might happen, and include in the forecast details for the worst of the plausible scenarios.

This differs from other forecasts, which give you the most-likely scenario.
10. What areas are covered in Regional Daily Email forecasts?
3 Regions available:
E Caribbean (E of 72W)
Bahamas/W Atlantic/US E Coast (as far N as Southern NewEngland in summer)
W Caribbean (W of 72W)
11. What is the "<" symbol in my email forecast
The < symbol indicates a change in conditions over the relevant time period. Read "<" as "becoming".

"240@18<15 this afternoon" means wind will be 240-degrees, starting this afternoon at 18k and becoming 15k.
12. What is "N ROUTE" and "S ROUTE" in my email forecast?
The Bahamas Regional Email forecast offers specific forecast and recommendations on the GulfStream between:

FtPierce / LkWorth - to - MantanillaShola / MemoryRock / WEnd (N ROUTE)

Miami / FtLaud / KyLargo - to - Bimini / S RidingRk / GtBahamaBk (S ROUTE)
13. Regional Daily Email forecast Primer
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

LO = low pressure system

2nd-ary LO = LO which forms along FRONT trailing from a LO, generally causing inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (and ColdFRONT / WarmFRONT) = flat, weak area lower pressure along an axis, typically causing nasty weather

2nd-ary FRONT = often a LO supports more than one ColdFRONT. 2nd-ary FRONT(s) reinforce the established flow and often bring more veering of wind direction

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become one). Maybe it’s an area along a TROF (or a ColdFRONT or a WarmFRONT) where there’s more wind / seas / squalls. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 seconds feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to DryTortugas
SW FL = Marathon or KyW to Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.
14. Regional Daily Email forecast Primer
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

LO = low pressure system

2nd-ary LO = LO which forms along FRONT trailing from a LO, generally causing inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (and ColdFRONT / WarmFRONT) = flat, weak area lower pressure along an axis, typically causing nasty weather

2nd-ary FRONT = often a LO supports more than one ColdFRONT. 2nd-ary FRONT(s) reinforce the established flow and often bring more veering of wind direction

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become one). Maybe it’s an area along a TROF (or a ColdFRONT or a WarmFRONT) where there’s more wind / seas / squalls. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 seconds feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to DryTortugas
SW FL = Marathon or KyW to Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.
15. Regional Daily Email forecast Primer
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

LO = low pressure system

2nd-ary LO = LO which forms along FRONT trailing from a LO, generally causing inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (and ColdFRONT / WarmFRONT) = flat, weak area lower pressure along an axis, typically causing nasty weather

2nd-ary FRONT = often a LO supports more than one ColdFRONT. 2nd-ary FRONT(s) reinforce the established flow and often bring more veering of wind direction

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become one). Maybe it’s an area along a TROF (or a ColdFRONT or a WarmFRONT) where there’s more wind / seas / squalls. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 seconds feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to DryTortugas
SW FL = Marathon or KyW to Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.
16. I have stopped receiving email forecasts, even though my subscription is current
Email Service Providers attempt to limit SPAM by "blacklisting" servers which send a large percentage of emails which are undeliverable or whose recipients mark then as SPAM.

In an effort to make sure our server is not flagged as a Spamming server, we have a "gatekeeper" which prevents our server from sending email to an address which has previously flagged us as SPAM or has had any sort of email delivery problem (like an expired email account or a misspelled email address).

Solution: please email us, and we'll eliminate your email address from our email suppression system.
17. What methods of payment are accepted?
We accept Visa, Mastercard, Discover, and American Express.

If you strongly prefer to pay by check, please contact: chris@mwxc.com
18. I'm not getting email forecasts I signed-up for.
First, check settings on your account/subscription:
1. For all emails, make sure you have the appropriate address(es) selected to receive forecasts.
2. For Regional Daily Forecasts, do you have a current Subscription?
3. For Regional Daily Forecasts, make sure you have 1-or-more "Regions" selected.

If the above are correct and you're still not getting forecasts, then contact Chris Parker:
863-248-2702
chris@mwxc.com
support@mwxc.com

The following is a description of the likely culprit:

We have a "smart" email system (maybe too smart).

In this world overflowing with SPAM, the last thing a legitimate email sender wants is to be "blacklisted" as a spammer, or to have our SPAM SCORE so high that legitimate emails end-up getting automatically filtered into the recipient's SPAM folder.

Our system tries to prevent this in 2 ways:

1. If you ever (even once by mistake) flag an email from Marine Weather Center as SPAM, and your email service provider sends that information to our server, our server will never send you another email.

2. If an email to you ever bounces (is undeliverable) for any reason (you let an email address lapse, etc), our server will never send you another email.

In the above cases, even if our List Server follows your instructions to generate the email forecast, our email "Policeman" prevents our server from sending your forecast.

If you contact me, I can make our "Email Policeman" FORGET there was ever a problem delivering mail to you...and it should then allow email forecasts to pass to you.
19. Is your website secure?
Yes, mwxc.com website has a SSL 3.0 security certificate (notice the "https" on the sign-up form).

We follow credit card industry "best practices", and every 3 months we re-verify "PCI-compliance".

Here's what happens when you make a payment on www.mwxc.com:

Our server checks the order for errors, and, if none, submits your information for payment authorization. The very second your payment is approved, your subscription is active (or your scheduled product is on the schedule).

CREDIT CARD DETAILS: our server only acts as a conduit, establishing a secure Internet connection with ePN processing network, which only acts as a conduit to pass your credit card information to the appropriate Card Network (Visa, Mastercard, Amex, Discover). This Card Network verifies information with the bank which issued your credit card, and either approves or declines the transaction in realtime. Later that night, the Card Network "settles" the transaction with the Bank which issued your card, and pays ePN, who then pays Marine Weather Center.

Neither the www.mwxc.com website nor ePN ever store your entire credit card number.

Instead, we store the last 4 digits and expiration date. We also store a unique code which the Card Network assigns to purchases by you at Marine Weather Center.

When you renew, or purchase additional weather services with the same card you used previously, we submit to the Card Network the last 4 digits of your credit card, the expiration month/year, and the unique code, and the transaction processes just as if a full credit card number was submitted.

The benefits for you and us are:
1. Neither Marine Weather Center nor our Merchant Processing Company (ePN) ever store your full credit card number.

2. The "unique code" provided to us by the Card Network is password protected. But even if it were obtained fraudulently, it would only work to approve transactions for which payment would come to Marine Weather Center (so it would be of no use to a criminal).

While this is no guarantee your data is 100% secure, it is as secure at www.mwxc.com as it is on the Internet's other "most-secure" websites.
20. How can I receive my forecast?
Via ANY communications capabilities beyond VHF radio. Basically, if you can communicate with the outside world beyond VHF range, you can receive our forecasts. Methods include: email, phone, fax, and SSB radio voice nets.
21. Can you email me a copy of an old forecast / forecast for a previous day?
Actually, you can retrieve ANY email forecast which was sent to you since April 15, 2011.
Login to your account, then click "View/Search All Regional Forecasts"

We are working on allowing access to email forecasts since April 15, 2011, for Regions which were not sent to you, and for any periods for which you were not a subscriber...if you need one of these, please email chris@mwxc.com
22. Custom (vessel-specific) forecasts by Email
Many clients use our Custom (vessel-specific) email forecasts.

Forecast (except general 10-day Outlook) generally includes:
1. summary of current weather and sea conditions
2. SYNOPSIS of major weather features and their expected influence on you
3. analysis of and optimized routing based on Sea Surface Currents
4. Detailed forecast of wind speed and direction; estimate of wind in squalls; and height, direction and interval of both swells and wind-driven seas - all every 12-hours out to 2-days or 5-days, with more-granularity to time intervals near significant weather events.
5. suggested TACTICS you may wish to employ to optimize your trip, given the expected conditions at each 12-hour interval.
6. suggest when you may want to request your next forecast Update

You can order the initial forecast on the website www.mwxc.com or by phone or email.

Forecasts can be charged to your credit card as you request them, or you can purchase a package of forecasts in advance, as follows:

--Detailed 5-day forecast and routing advice with 10-day Outlook $65
--Detailed 2-day forecast and routing advice $35
--General 10-day Outlook $35 (useful for ensuring vessels on long passages are maintaining the best route for the overall weather pattern, while the vessel handles their own day-to-day forecasting)
--Package of (10) Custom forecasts for $250 (each $35 forecast or $30 phone-in forecast will count as one (1) forecast / each $65 forecast counts as two (2) of your ten (10) forecasts).

TO REQUEST SUBSEQUENT FORECASTS:

email me in the morning with the following, and I'll email your forecast later in the day:

1. your Location, course and speed
2. weather and sea conditions
3. your PLAN (and anything else I should know when preparing your forecast)
4. type of forecast you're requesting:
--5-day forecast $65
--2-day forecast $35
--general 10-day Outlook $35

Schedule your 1st forecast for 1-2 days before your earliest intended departure.

I'll contact you within 24hrs before sending the forecast to confirm favorable weather for your departure. If conditions are not favorable for departure, I'll continue monitoring weather (and communicating with you every couple days) until there's a suitable departure opportunity. So the 1st forecast includes a Departure Window recommendation.
23. I'm on a long passage. How much will Custom (vessel-specific) email forecasts cost?
Cost varies depending on how self-reliant you are, and how bad or changeable weather conditions are.

Some self-reliant folks cross the Atlantic with just 3 or 4 "general 10-day Outlooks" and one or two "2-day forecasts" when there's a significant upcoming weather event. Forecasts for their entire Atlantic crossing can be $100-or-so.

Other folks prefer more input from me on their forecasting and routing. Most folks request about $100 of forecasts each week on extended offshore passages.
24. I want a Custom forecast by email. How do you decide when to send the forecast?
When you order your initial Custom email forecast, please schedule it for 1-3 days before your 1st possible departure date. You will want to schedule the forecast for the day on which you will begin to make final departure preparations/decisions.

On the day you schedule, I'll look at your request, and assess the weather situation, and read any NOTES you've made on the order. Then I will contact you (by email or phone) to confirm when you'll be ready to depart, and that the weather looks good.

If you are not ready to depart, or the weather is not good, then we'll re-schedule an assessment for 1-2 days later...and we'll keep doing this until you're ready to go and the weather is good.

The forecast is a single forecast (for 2 days or 5 days, whichever you choose). To order additional forecasts:
If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

When you want another email forecast, please email me the following in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).
25. What if weather is no good?
On the day before your forecast is due (2 days prior to your earliest departure date), if conditions do not look acceptable, I'll contact you by phone or email to re-schedule your forecast.

I'll continue doing this as many times as necessary to identify a departure opportunity you deem acceptable.

Of course, once we agree I should send you the detailed forecast, and I send the forecast, if you later decide not to go, the order will still be considered to be completed.
26. How do I order another forecast?
CUSTOM FORECASTS:
If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT

Text message (including Garmin Explorer / DeLorme InReach): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure to ask a specific question, so as can be sure to provide the best answer in the constraints of SMS messaging. Cost is same as 2-day Custom email forecast $35 or 1 forecast credit).

When you want an email forecast, please email us the following in the morning and we will email your forecast later in the day (we can also schedule these in advance):

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250. ANY forecast credit can be used for ANY Custom forecast, so purchase either 10-pack of credits for $250).

TO PURCHASE:
If you do NOT have an account, please visit www.mwxc.com then click any orange "sign-up" link then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT.

If you DO have an account, login to your account (if you do not remember your credentials follow the prompts to "Retrieve your login information"). Once logged in, either Renew your previous service or click the "SIGN-UP NOW FOR NEW SERVICES" link.
27. Will you monitor the weather and contact us if things change?
No. Some folks might object to a forecaster contacting them (and billing them) for a forecast when they don't need it. I have no shortage of work, and no desire to charge you for anything you don't feel you need.

INSTEAD, each forecast includes my recommendation on when you should contact me for another forecast. For instance, if there is a little ColdFRONT expected on Friday, and a small uncertainty in its track, I might suggest you email me for a forecast Thursday, so you have a day to make small alterations in course...if it's a major system and/or a major uncertainty and you might require more advance notice to make a bigger course change, then I might suggest you email me Wednesday or even Tuesday.

Although not every forecast verifies with 100% precision, each forecast includes a discussion of uncertainties / forecast confidence, and possibility for severe weather. Almost all forecasts which which require frequent revision do so because of uncertainties or potential for severe weather which we discussed previously.

You may also notice your weather conditions are beginning to deviate from the previous forecast, and you'll decide you want an earlier update.
28. I'm on passage, and want a forecast emailed to me each day, can you do that?
I'll be glad to email you a forecast each day.

However, I ask that you email me each morning you want a forecast with your:

1. location, course, speed
2. weather/sea conditions
3. PLAN, and anything else I should know when creating your forecast
4. REQUEST that I email you one of the following:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

WHY DO I NOT JUST EMAIL FORECAST AUTOMATICALLY?:

My strong opinion is you need a weather forecast/routing advice in order to answer questions / make strategic decisions.

My forecast is NOT the "most likely scenario" you may get from other sources. Rather, it is the worst-plausible scenario for your situation, and I include routing and strategic advice/suggestions which you can use to optimize your passage.

Although I'm pretty good at guessing and pro-actively providing the answers to questions/decisions you may need to make, my forecasts will be FAR MORE USEFUL if they specifically address your:

a. overall PLAN
b. strategic discussions you've been having onboard
c. and if I take into account any vessel/crew issues you may be having

The only way I know this information, and can provide the best value-added forecast/routing advice is for you to email this information before I begin preparing your forecast.
29. How often should I request a new Custom Email forecast?
See the above answer for clues it's time to ask for another forecast.

In general, for extended offshore passages, clients request 2-3 forecasts per week.

I've worked with self-reliant folks who only needed 1 general 10-day outlook each week on their trans-Atlantic passage, to help ensure they were at about the optimum Latitude, and not at risk for a severe storm. These clients can cross the Atlantic on 4-5 forecasts for a total of $100-$150.

More typical is a client requesting 1 or 2 detailed 5-day forecasts per week, and 1 or 2 detailed 2-day forecasts the day before inclement weather...for a total of about $100-or-so per week.
30. Can you give me a waypoint to head toward?
Occasionally there's a good reason to aim for a specific waypoint, and, when this is the case, I'll give you a specific waypoint.

However, it is my strong opinion that clients are best served by sailing their vessel in a manner which is fast and comfortable, while heading basically in the right direction.

For instance, I had 2 clients heading from Florida to E Caribbean this week.

One seemed hell-bent on maintaining a due-E course in spite of strong SE wind, and he ignored or didn't understand my advice to sail "whatever course is comfortable basically to the NE-E". He got battered-up, turned around, and sailed 2 days back to Florida.

The other vessel was more-flexible, sailing generally NE-E, on a consistent beam reach in the brisk SE-S wind, and - he's now sailing nicely E-ward, with mild S wind and excellent prospects for a mild trip to E Caribbean with mild N wind next 2-3 days, before reaching NE-E Trades.

Again, there are situations where navigation is restricted, or where weather trends make sailing in a specific direction (and achieving a specific waypoint) imperative. More often, however, maintaining a comfortable sailing angle while going generally in the right direction is preferable.
31. Sharing forecasts with others
You are purchasing limited rights to use my intellectual property on your vessel and, unless you have my express permission, you may NOT redistribute, or cause to be redistributed, my forecasts for use on a vessel you are not physically on.

However, there are some ways you can share:

Feel free to put my forecast into your own words, and share this with others. Be sure you note it's your interpretation of my forecast. Sharing my words is NOT OK. Expressing your own words is fine, as long as people don't think they're my words.

If you believe sharing my forecast on a single occasion may motivate a potential new client to purchase my services, then it's OK to share MY WORDS on that one occasion. However, this is NOT OK on a recurring basis, or if you do not think there's a reasonable chance the sharing could prompt the person you're sharing with to purchase services.

32. Position Reports
Many vessels have the ability to send Position Reports, and I find these useful in several ways.

I established a special email address for receiving Position Reports from clients. Please send (or copy or blind copy) Position Reports to: spot@mwxc.com

In order to match the Position Report to a client (so I can provide better service to you), I need one of the following in the SUBJECT LINE of the Position Report:

A. whatever characters are in the "SSB Call Sign" field of your account at www.mwxc.com (this can be an SSB or Ham Call Sign - but NOT BOTH).

B. the 4-digit "SPOT Email Identifier" field of your account at www.mwxc.com (a 3 or 4 digit number unique to your vessel, assigned by my system, with a "#" symbol before & after the number).

To find either of the above, login to your account at www.mwxc.com (if you don't know your username/password, click "Retrieve Your Login Information" from the Login page, and my system will generate a new password and email it to you).

When my system receives a Position Report at spot@mwxc.com it attempts to match words in the SUBJECT LINE of the Position Report to the "SSB Call Sign" and "SPOT Email Identifier" fields of your Client Profile.

Once a match is made, your position is plotted on an interactive map I use to track clients and monitor real-time weather information. See the FAQ on Interactive Weather Map.

In addition, my system attempts to "parse" any weather observation details your Position Report may contain into numerical data, which it graphs for me, so I can see recent weather observation details throughout the area.

And my system displays (and I read) any additional text/comments from your Position Report.

Position Reports can be submitted by any combination of:

SPOT device from Glogalstar (Original SPOT, Spot Connect, SPOT G3), but the SPOT phone is just a phone, and not a position reporting device.

DeLorme InReach

WL2K

YOTREPS

Email via any method

Specific requirements for each are below.
33. Do you provide service for vessels Crossing the Atlantic?
Yes. I work with many vessels each year on both E-bound and W-bound Crossings of the Atlantic.

We can work via SSB Voice Nets, voice telephone, email, SMS text messaging, or any combination.

SSB Nets should work all the way to the Coast of Europe, depending on propagation and the quality of your radio installation.

No SSB? Many folks prefer email and/or voice telephone or have no SSB, so we can communicate via email and/or voice telephone or even SMS text messaging for any part of the trip.

Pricing:

SSB Nets $199, includes unlimited Daily contact, as often as 7 Days/week, but you just hail me when you want a forecast, there is no daily check-in requirement.

Forecasts by phone/email, as follows:
10 prepaid forecast credits for $250 may be used as follows:

phone-in ($25/call or 1 forecast credit)
email Detailed 5-day forecast ($65 or 2 forecast credits)
email Detailed 2-day forecast ($35 or 1 forecast credit)
email General 10-day Outlook ($35 or 1 forecast credit)

To purchase any of the above: visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form. Your order will process in real time and you will receive an automated confirmation email. If not, please call 863-248-2702 to place or troubleshoot your order.
34. How do I use your service on my upcoming ocean voyage?
We offer weather forecasting and routing advice via telephone, email, SMS message, SSB Radio, live interactive Internet Webcasts, and recorded forecasts. Basically, if you have any communications capability beyond VHF range, we can provide forecasts and routing advice!

SSB Voice (including simultaneous Internet Webcasts & recorded forecasts) is $99/mo or $199 for a year.
Add our Daily Regional EMail forecast for $100 for a total of $299/yr.

Alternatively (or in addition), we can work by voice telephone and/or email, as follows:

For some upcoming passages you may want a detailed 5-day email forecast prior to departure, then occasional vessel-specific email updates while underway. Order your initial 5-day email forecast anytime.

While underway, when you want a vessel-specific email forecast, please email me in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

You can purchase any/all of the above on my website www.mwxc.com (click any orange "sign-up" link, then complete and submit the form), or call me 863-248-2702 for assistance if you have questions...Chris
35. How do I use your service for Cruising the US E Coast and Bahamas/Caribbean?
We offer weather forecasting and routing advice via SSB Radio Voice, email and telephone.

Best value is probably SSB Voice is $99 for the trip or $199 for a year.

SSB Nets work very well when combined with our Regional Daily Email forecast (which is NOT "vessel-specific", but does include forecast details to support good decision-making on a small vessel in the Bahamas/Caribbean and making the Coastal migration N & S during the Spring/Fall respectively)...and also includes details on all Tropical systems. For instance, with Ana, Regional Daily Email forecasts mentioned the possibility of Ana 10 days ago, and beginning last Tuesday May 5, offered specific forecasts and guidance about where/when to avoid (I think about 48hrs before NOAA).

Regional Daily Email forecasts $55/mo, or $199/yr, or $100/yr when combined with SSB Nets.

*.*

Alternatively (or in addition), we can work by voice telephone and/or email (these take longer to prepare and therefore incur a per-forecast charge), as follows:

You might want a detailed 5-day email forecast prior to departure, then occasional updates while underway. Order your initial 5-day email forecast anytime.

While underway, when you want an email forecast, please email me in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

You can purchase any/all of the above on my website www.mwxc.com or call me for assistance if you have questions...Chris
36. I purchased a package of 10 pre-paid forecasts. How do I get a forecast?
You purchased 10 prepaid forecast credits. They can be used as follows:

You probably want a pre-departure detailed 5-day forecast . When you have some idea of the date you'll be ready to depart, please call or email me to schedule the initial forecast. I typically send forecasts the day prior to your departure. But if you need more pre-departure planning, I can schedule forecasts farther in advance.

When you want another email forecast, please email me the following in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)
d. If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

If you have questions, let , me know...Chris.
37. Pacific Ocean - do you provide forecasts, or know someone who does?
I provide weather forecasting & routing advice for the Pacific Coast of Central America, and adjacent waters, including:
Colombia & Ecuador, Galapagos, and Panama to SanDiego

Forecasts for this area are via SSB Voice Nets or Custom Email or phone-in forecasts (NO "Regional Daily Email forecasts").

If you're heading N of SanDiego, S of Ecuador, or W of the Galapagos, then I suggest you use a different resource.

For folks heading to the SouthPacific, there's Bob McDavitt:
http://weathergram.blogspot.com/
38. Is your book, Coastal & Offshore Weather, the Essential Handbook, available as an E-Book?
No, but I'll be glad to ship you a printed copy.

I spent hundreds of dollars having the book converted to a Kindle E-book, and the finished product was so bad I couldn't sell it.

Kindle is great for text-only books. But books heavy with images (as mine is) are a problem...and, if I spend thousands of dollars on a good Kindle rewrite (assuming that's even possible), Amazon's pricing model is such that I'll never get my money back.

E-books are great for high-volume, text-only books.

My experience is that it's horrible for graphics-heavy, low-volume books.
39. Evening SSB Nets?
Afternoon Net is at 2200 utc on 8.137 & 12.350 USB. When there's not a lot of traffic (July-April) we come on the air at 2200 utc, ask for Emergency/Priority traffic, then call for any Subscribing Vessels wanting weather info. We typically start in the W Caribbean (since that's where antennas were turned in on the last morning Net)...then work into Bahamas/E Caribbean...then waters N of Caribbean...then US E Coast & NW Atlantic.

All of this typically takes 15 minutes, then we're done...so there are no set times for pointing antenna in any direction.

During busy months for long-range passages to Europe (May-June) the evening Net may take an hour or more. When this happens, we come-up at 2145 and build a list of vessels with traffic for Marine Weather Center, then, at 2200 utc, we begin working the list of vessels with traffic - in the most logical order.

Propagation in the evenings is typically better (and longer) than mornings, and this Net is geared more to passagemaking than to vessels making day-hops, but it is open to any Subscribing Vessel. Also, Florida and areas within 100 miles of Florida are problematic because we skip over each other on 8-megs & 12-megs.
40. DeLorme InReach / Garmin Explorer?
We can get quite detailed.

Recently we sent the following detailed forecast for a vessel on passage via his InReach...this forecast took 5 InReach messages, but for short-term Coastal sailing we can usually keep it to 1-3 InReach messages and still convey a very good, specific forecast and advice.

We charge $30 per forecast or $250 for (10) forecasts, good for a year. Regardless how many messages it takes us to convey the information, we only charge you for 1 forecast:

*.*

You are getting into GulfStream, and there is NO PROBLEM with lying farther E than intended.
SUGGEST you try to maintain Course Over Ground 360T.

You will EXIT GulfStream along a LINE:
38N/68W
38-15N/67-40W
Once out of Stream, aim for SalemMA.
Tonight: 240@16-20g25, squalls/T-strms 30-40k, 6-9'.

It is OK if you sail whatever course is comfortable, even if that's slightly E-of-N in terms of Course Over Ground.

N of GulfStream Mon10: variable mostly S-SW@0-15, 2-4', you may need to motor/motorsail.
Mon10 night: becoming steadier 230@10-15g20, 2-4'
Tue11: 210@15<23g30k

Tue11 night: 230@23g30, 8'
Wed12: N of 42N falls L&V, motoring toward Salem.
Thu13: uncertain, IMPULSE or LO moves ENE from NewEng, but weather will be OK.

*.*

Purchase at www.mwxc.com by clicking any orange "sign-up" link, then complete and submit the form (you want the 10-pack of Custom phone-in forecasts for $250).
41. Typical seasonal weather in E Caribbean
From about mid-December thru most of March weather systems to the N are amplified...and the big / strong areas of HI pressure to the N drive your brisk Trade wind / seas.
During this time there are intervals of milder conditions (lasting from a couple days to a couple weeks), and you should use those intervals to move. We had a couple weeks in late January where conditions were very mild (even too light for sailing) for most of 2 weeks.
Late March thru early June brings changeable weather...with more frequent & longer-lasting intervals of very light winds/seas as the sub-Tropical RIDGE is pressed S into the Caribbean. The direction of Trades also usually begins shifting from ENE to E-ESE....and in May-June squalls begin becoming more significant with weak TropicalWAVEs.
June thru September we get into a pattern of squally TropicalWAVEs with 1 day of really nasty weather with wind veering NE The other thing common in May-June is early-season W-moving TropicalWAVEs reach the Caribbean and interact with E-moving weather just N of the Caribbean...and this sometimes causes TropicalWAVEs to stall & linger for days or even a week. We can see day-after-day of heavy rain and strong wind in squalls...not a huge deal if you're in a protected anchorage, but this causes rock & mud slides on mountainous islands.
In the absence of stalling TropicalWAVEs, May-June tend to be pretty nice months.
42. Crossing Atlantic
Yes, we provide forecasts and routing advice via email, phone, text, and SSB Voice.

We can communicate via SSB Voice Nets for $199 for the entire trip (or for as long as propagation allows which should be most of the trip).

Alternatively (or in addition), Custom forecasts by email, voice telephone, and text message for $30-$65 per forecast, or $250 for a 10-pack of Custom forecast credits.

Most boats rely on us to supply about (2) detailed 5-day Custom forecasts each week, and occasionally a detailed 2-day Custom forecast before any major decisions or high-impact weather events (about 4-5 Custom forecast credits per week).

But we also offer just a General Outlook for those who want to do most of their own day-to-day forecasting work. Below are more details, and you can request whichever suits your needs on a particular day:

1. The 10-day Outlooks are just a high-level overview of the Synoptic weather pattern, and SeaSurfaceCurrents, and give a couple suggested Waypoints, and some detail on 1 or 2 instances of significant weather expected in that 10-day timeframe. You handle your day-to-day detailed forecast on your own. You request from us maybe (1) 10-day Outlook each week (using 1 Custom forecast credit), to ensure you're basically heading in the optimum direction.

2. Detailed 5-day forecasts include the 10-day Outlook (so you do NOT need to order the 10-day Outlook), PLUS a detailed 5-7 day wind forecast, including more waypoints, sailing strategy suggestions, detail on seas and squalls. This uses (2) Custom forecast credits, but we do all the forecasting work for you (so you don't need to do forecasts on your own, but we encourage you to do as much forecasting work as possible so you have a deeper understanding of the weather situation), You probably need just 2 of these forecasts per week, on average (more frequently if weather is dynamic).

3. Detailed 2-day forecast (1 Custom forecast credit) includes just the next 2-3 days in detail, and is best used to refine forecast and routing advice for an upcoming Decision Point along the voyage or a high-impact weather event.

Again, most vessels request about (2) of the detailed 5-day Custom email forecasts each week, so for the entire trip to the US plan on (2) of the 10-packs of Custom forecast credits for a total of $500.

Purchase the 1st 10-pack at www.mwxc.com by clicking any orange "sign-up" link, then complete and submit the form, or call 863-248-2702 and we'll assist over the phone.

So we're here as much or as little as you feel you need us....and we look forward to working with you...Chris.
43. Hurricane Season 2020 options
Indeed, we published something you might find very useful...it's on our website here:
https://mwxcblog.com/tropical-season-2020/

Our article is also on www.Noonsite.com and will be in the Caribbean Compass magazine in May.

Staying in the Caribbean is a viable strategy.

Some clients have checked with local customs/immigration, and verified that, if they depart and go sailing for a hurricane, and never make landfall anywhere else, they will be allowed back into the island from which they departed.

You may want to verify that's allowed where you are.

The strategy for what to do in a given situation when there's an approaching Tropical LO depends on many things, and is best addressed with each vessel when the time comes.

We are offering to monitor weather for you, and let you know when we think there's a meaningful Tropical threat, and then provide a pre-departure forecast and routing advice to evade the threat. Cost $65, and the product is our detailed 5-day Custom email forecast.

To purchase:
If you have an account, please login then click the SIGN-UP NOW FOR NEW SERVICES link.
If you are a new client, visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form.

Let us know how we can help...email chris@mwxc.com or call 863-248-2702...Chris.
44. InReach
When you need a forecast, please message from your InReach device to:chris@mwxc.com with the following:
1. your location (if your unit has a GPS fix it will include this automatically)
2. your course and speed
3. weather conditions
4. ask a question, so we know you want a response and so that our response can be most relevant to decision making
You may not need a forecast every day, but when you need one, please request one...Chris.

InReach is NOT email.

It is a short text messaging device only.

The only way we have had nearly 100% success is if you message us from the InReach device to:
chris@mwxc.com

Do this before you depart, and ask that we acknowledge receipt of your message.

When we receive your message, it contains a LINK we can use for all future communications (think of it like a key to a locked door...with that message to us, you have given us the key).

*.*

Below is an exchange we had with a client recently. He is without engine, and trying to get from E of the Abacos to BeaufortNC. This is longer than a typical exchange, but you get the idea...Chris.

His messages to me:
26-30N/76W, course 302T, 1.4k

Can you plse advise best strategy for destination Morehead City sail only at 4.5k avg

NO ENGINE No heading at this time but we understand wind will pick up Tuesday night Destination Morehead City

*.*

OUR FORECAST:
Although BeaufortNC is only 500 miles away, it is going to take you a week to get there, because mostly wind on the nose or no wind, and only brief intervals of

favorable wind.
In General:
Tue5 night S wind establishes, veers SW Wed6, then FRONT brings brisk NNW wind Dawn Thu7, veers N Thu7 night.
No wind Fri8.

Fri8 night S veering SW wind, but N wind Sat9, veers NE Sat9 night, light E wind Sun10, no wind Sun10 night into Mon11.
Wind is briefly SW Mon11 evening, but

N behind another FRONT Mon11 night into Tue12 morning, then no wind again Tue12 afternoon, and N-NE wind again Tue12 night-Wed13.
Building E wind Thu14.

Do you maybe want to select another destination? Somewhere in FL? Or maybe CharlestonSC?
Short term forecast:
Tue5 overnight: building from 150@8 to 190@11.

Wed6 builds from 190@11 to 220@10-14g17, STRATEGY: tonight-Wed6 sail course 330T.
Wed6 evening, near 28-15N/77-05W: veering 240@15g20.
Wed6 overnight: veering

from 240@15g20 with a few brief squalls to 40k, then 320@20-23g30 behind FRONT, STRATEGY: sailing 330T then 030T.
Thu7, near 29-30N / 76-45W: 330@20-23g30

settling to 17g22k.
Thu7 night, 30-30N / 75-50W: 340@16g20 veering 360@12 then falling L&V, sailing 045T then 060T then drifting.
Fri8, 30-45N/75-30W: L&V then

S@16, sailing 340T.
Fri8 night, 31-20N/75-40W: building from 200@17 to 250@25g35, sailing 340T.
Sat9 morning veers 330@25g35 and U sail NE so U R near 32N/75W.

During the day Sat9 wind veers N and settles to 15k, U sail 060T.
Sat9 night wind veers NE-ENE and U TACK and sail NW to 32-45N / 75-30W, then Sun10 wind may

die.
I am concerned if U get into GulfStream this far E, and with no wind, then U may be swept past Hatteras.
Therefore, DECISION POINT is Thu7 when U could

make decision to TACK and sail W as wind veers to NNW, and aim for Charleston.
Or U could head as much to the W as possible at all times and maybe make N FL?

This is msg 13 of 13. Any questions?...Chris.
45. After arrival
Congratulations on your safe arrival!

We'd love to continue providing weather forecasts and routing advice for your further travels.

We provide forecasts and routing advice for sail and power vessels worldwide, with 3 distinct offerings:

1. Custom forecasts, just for your vessel and itinerary - you let us know where you are, where you're heading, and when you hope to depart...and we help you choose a departure date/time then provide a detailed forecast and routing advice including details on currents, squalls and fog if relevant (more detailed and more specific to your needs than we supplied on the Salty Dawg Rally).

Geography covered = the entire world. Forecasts via email, phone, text, interactive Webcast, at a time convenient for you. Cost $30-$65 depending on length of forecast, or 10-pack of Custom forecast credits for $250.

2. Alternatively (or in addition) economical Regional Daily Email forecasts, covering the Caribbean, Bahamas and entire US E Coast as far NE as ShelburneNS. While these forecasts are not specific to your vessel, they should provide the information you need to make good weather-based decisions. Includes unparalleled coverage of Tropical systems throughout the Atlantic. Cost $199/yr, $99 for 3mo, or $55/mo.

3. Custom forecasts and routing advice via SSB Voice Nets and simultaneous Internet Webcasts. We can discuss departure timing, forecast, routing, currents, anything else you wish - just for your vessel and itinerary - mornings from 6am-9am and for a few minutes at 6pm. Cost $199/yr, or COMBINE with Regional Daily Email forecasts for $299/yr total.

To purchase any of the above, login to your account at www.mwxc.com and click the SIGN-UP NOW FOR NEW SERVICES link, or call 863-248-2702 any day after 10am EDT.

We look forward to working with you on your next move...Chris.
46. Definitions: TROF, RIDGE
TROF: A TROF is any area of lower pressure which is elongated along an axis.

LO pressure system is symmetrical (round) or elongated / somewhat of an oval shape, and wind circulates around it in a counter-clockwise direction.

A TROF is an area of lower pressure which is flat - it lies along an axis...and air tends to flow toward that axis, as well as moving upward in altitude.

Examples of TROFs include ColdFRONTs, WarmFRONTs, StationaryFRONTs, TropicalWAVEs, and others.

If we simply use "TROF" by itself, then it is typically a boundary in the atmosphere along an axis (say from 30N/40W to 25N/50W), and it is neither a WarmFRONT (advancing warm airmass), nor a ColdFRONT (advancing cold airmass), nor a TropicalWAVE.

Because air along a TROF is converging toward the TROF, and also rising in altitude a TROF tends to bring cloudy unsettled weather and it can be squally.

*.*

RIDGE:
An area of HI pressure is symmetrical (round) or oval in shape, and air flows around it in a clockwise direction.

A RIDGE is a flattened (very elongated oval) that's not as strong as most more-symmetrical areas of high pressure.

RIDGEs and HI pressure systems are characterized by sinking, downward-moving air which diverges away from the RIDGE at the surface.

This sinking air tends to be fair and stable (fewer clouds and no squalls) - except in warm, moist environments pockets of convection (parcels of air warmer than surrounding environment) can overcome the broad downward-moving airmass and still produce thunderstorms.
47. Concerned about Tropical LO pressure systems in the Caribbean, Bahamas, or elsewhere?

We offer a service where we monitor possible Tropical threats, and if we identify a threat to your location, we'll contact you to establish a dialog.

We normally classify a threat as any meaningful chance an approaching Tropical LO (or potential Tropical LO) could bring you TropicalStorm (35k+ sustained) winds from any direction, or more than 10k of wind from a direction from which you might not be protected.

Cost is $65 (or 2 Custom forecast credits) to monitor and alert you to a possible threat, and to provide Regional forecasts which cover the potential threat as the system approaches. This also includes consultation on whether we recommend you take action ahead of the approaching threat.

If you decide to take action by getting underway to avoid the threat (or if you want a Custom forecast for where you are), a detailed 2-day email forecast (or a text message) is $35 (or 1 Custom forecast credit), or a phone call is $30 (or 1 Custom forecast credit). You might need a couple of Custom forecasts immediately before and during the event.

When that Tropical threat has passed, we can schedule another monitoring type forecast for $65 for the next possible Tropical threat.

To get started, please decide whether you want to start with just a single $65 monitoring-and-alert forecast...or whether you want to purchase the 10-pack of Custom forecast credits (they're good for a year, details below).

If you do NOT have an account, please visit www.mwxc.com then click any orange "sign-up" link then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT.

If you DO have an account, login to your account (if you do not remember your credentials follow the prompts to "Retrieve your login information"). Once logged in, either Renew your previous service or click the "SIGN-UP NOW FOR NEW SERVICES" link.

You may also request forecasts by email, phone, or text message.

FORECASTS:
If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT

Text message (including Garmin Explorer / DeLorme InReach): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure to ask a specific question, so as can be sure to provide the best answer in the constraints of SMS messaging. Cost is same as 2-day Custom email forecast $35 or 1 forecast credit).

When you want an email forecast, please email us the following in the morning and we will email your forecast later in the day (we can also schedule these in advance):

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250. ANY forecast credit can be used for ANY Custom forecast, so purchase either 10-pack of credits for $250).

*.*

CONFIRMATION:
Your Tropical weather monitoring is ON, for Martinique.

If we identify a threat to your specific location from a declared Tropical LO (or anything that might become a Tropical LO), which might bring 35k+ sustained winds, or 10k+ winds from directions you're not protected) we will:

1. email you to initiate a dialog about the timing, probability, and potential magnitude of the threat.
2. turn ON our Regional Daily Email forecasts for the duration of the threat.

You have a FREE detailed 2-day email forecast, text message, or phone call on your account to use anytime in the next 12 months.

If you decide to take action by getting underway to avoid the threat, you might need additional Custom forecasts, and we can bill you for these only if/when you request them.

If there is a Tropical threat and we do as described above, then after that Tropical threat has passed, if you wish we can schedule another monitoring type forecast for $65 for the next possible Tropical threat. Hopefully there are no Tropical threats!

Please do let me know where you are, and if you move please login to your account and change the "JOURNEY / Embarking From" location to reflect your updated location, or email us and we'll update your location for you.

We look forward to assisting...Chris.
48. InReach for SDR
Forecasts will begin to your email address (NOT to InReach) about 5 days prior to departure, by email.

If you are using InReach (or other satellite text messaging device) for offshore communications. PLEASE test prior to our departure.

Send message from InReach to:
chris@mwxc.com
and ask us to reply.
After you receive our reply, you will know we can communicate.


When you want a forecast via InReach (or other satellite text messaging device), please message us the following info in the morning and we will reply with your forecast later in the day:

#1: course / speed
#2: weather / sea conditions
#3: ask a question so we know you want a response, and so that our response can be most relevant

When weather is settled, you should not need a forecast every day. Forecasts normally include suggestion on when we suggest you request another forecast.

*.*

Also,

1. Please change the SUBJECT LINE of your messages to include your boat name. This way, every time I get a message, I do not have to search for a person's name in our database to determine which boat it is.

2. When using particularly InReach / Explorer, please make sure the unit has acquired a GPS fix before sending message. Many messages come through with no position, and some positions on tracking map are delayed. If you ensure InReach / Explorer is sending position, then I'll know for sure where you are.

Cheers...Chris.
49. SDSA Wx Info "Push / Pull"
SDSA supplies me with initial information to add an account in our system for each participant. Sometimes your plans, communications capabilities, or other details change. In addition to updating SDSA, you should login to your account at www.mwxc.com to make changes, so we can provide support.

How we supply weather information ("push" versus "pull")

We "PUSH" information to Dawgs only by email and SSB Voice Nets.

If vessel does not have offshore email and/or SSB Voice, then vessel needs to contact us for weather information (think of this as "PULL" delivery). Part of a communication with such vessel is to suggest when the vessel should contact us to "pull" information again.

Several reasons for this:
SMS text (to InReach/Explorer, SpotX, Iridium or InmarSat phone): every message needs to be individually formatted just for that vessel, so the information is relevant, actionable, and deliverable. It is not possible to do this every day for every vessel, but they don't really need it every day except in "high impact" situations. Best information is in answer to a specific question (vessel asks us a specific question, and we provide a useful answer and anything else we think they need to know).

Voice phone: calling sat phones can be expensive, and phones are often only "on" and available to receive calls when the user is actively holding the phone. So for convenience and necessity, vessels call us, not the other way around.

Several situations have come up where a vessel got into a bad situation when they did not have access to any of our "push" information, and they failed to reach out to us to "pull" information....Chris.
50. DECCA Channel
ALL LOCATIONS are in degrees-minutes (and decimal minutes)....NOT degrees-decimal degrees!!!!
ALWAYS do your own navigation to ensure you remain clear of navigation hazards.
DECCA channel is a marked channel, and you can cut-off the corners on both the E & W sides, making sort of an "S-shaped" route, and is well detailed on the Explorer charts, but I would head from the BlackPoint / StanielCay area to:
24-14.5N / 76-45.0W
24-14.5N / 77-00.0W
Then head for NW ChannelLight, but make sure you pass W of the following point: 24-30N / 77-20W
51. Example of Custom forecast Transatlantic
In the short term, after you passed N thru the FRONT there was a RIDGE / TROF / RIDGE pattern, with the sub-Tropical RIDGE S of the FRONT along about 26N / then of course the FrontalTROF near your location / another RIDGE NW of you, which caused your wind to be NE early Sat9.

During Sat9 afternoon-night that RIDGE shifted E, and is now centered near 40N / 40W….and as a result your wind has veered from NE
The 2 RIDGEs will merge, with the RIDGE near 40N / 40W shifting S&E into the sub-Tropics...and the next approaching ColdFRONT (which lies not too far away, about 300-400mi W of you) is supporting your S wind on Sun10 morning.

It's a fast-moving FRONT, but not strong, and it probably stalls somewhere near 32N or 33N Mon11 morning.

What to do next is a difficult decision.

If you move N into the wind N of the FrontalTROF (N of 33N) then an IMPULSE developing along the FrontalTROF W of you (almost a LO developing and turning the portion of the FRONT W of you into a WarmFRONT) will cause building ENE wind Mon11 afternoon, veering E Mon11 night...and this will force you to sail N info to stronger winds.

Fortunately, this IMPULSE shifts NE quickly, and as it passes N of you your wind veers from E
Wed13-Fri15 wind is mostly S
Alternatively you could motor E Sun10-Mon11, and then Mon11 night-Tue12 you would see wind veering from SE@7-12 to S@7-12, allowing you to sail ENE-E, and continuing S
With either of the above options, you would arrive near 35N / 38W on-or-before Fri15, staying ahead of the approaching ColdFRONT with wind SW@15 Fri15.

Then that FRONT probably passes you or weakens and wind becomes light for about 24-48hrs.

And this is followed by a stronger LO pressure system tracking ENE-E thru 45N/40W Sat16 night-Sun17, and this rebuilds your SW wind, which should carry you all the way to Horta (or very close).

The decision which way to go Sun10-Mon11 is very difficult in large part because there's uncertainty with how far S the FRONT presses Sun10 night-Mon11 morning before stalling. If it stalls near 34N, then if you are forced to sail mostly N for 24hrs thereafter, you could end up too far N.

So, after much deliberation, I'm going to suggest heading generally NE and E, probably staying S of the FRONT thru Mon11, then sailing from late Mon11 night-Fri15 on a nice reach in mild conditions.

FORECAST:
Sun10, near 32-30N / 49-30W: variable probably S-W@6<240@10-12, wind-chop 1'<2', STRATEGY: you could either drift N or E on whichever tack generates best apparent wind, or, if there's not enough wind for sailing, I would probably motor slowly on course 060T. I'm going to guess wind is really light most of the day, and you motor 060T most of the day, then sail 030T with wind 240@10-12 late afternoon.

Sun10 night, near 33N / 48-40W: 250@10-12
Mon11, near 33-20N / 47-50W: variable wind becoming mostly E but well under 10k, 0-1', Swell builds from 4'<8'/14secWNW. STRATEGY: motoring slowly course 060T.

NOTE: if FRONT passes you at any time Mon11-Tue12, and wind builds over 10k, I would:
--if wind is N of 070T, then I would sail close reach on Port tack (SE course).
--if wind is S of 070T, then I would sail close reach on Starboard tack (course N-NE).
--realize that over time wind will veer toward S, so you if you start on Port tack, you will soon switch to Starboard tack.

Mon11 night, near 33-40N / 47W: wind builds 090@7<090-110@10, wind-chop 1'<2', Swell 8=9
14secNW. STRATEGY: as wind builds toward 10k you begin sailing close reach to NNE.

Tue12, near 34-30N / 46-20W: wind builds and veers quickly, mostly 090-110<150@10-15g20, wind-chop 2-4', Swell 9'<7'/12secNW. STRATEGY: sailing close reach to the NNE
Tue12 night, near 34-40N / 45-05W: 150<190@12-15g19, wind-chop 3-4', Swell 7'<5'/12secNW. STRATEGY: sailing close reach
Wed13, near 35N / 43-50W: 190<220@12-15g18, wind-chop 3-4', STRATEGY: sailing beam reach
Wed13 night, near 35-10N / 42-25W: 220@12<200@12-15g20, wind-chop 3'<3-4', STRATEGY: same.

Thu14, near 35-20N / 41W: 210@12-15g19, wind-chop 3-4', STRATEGY: same.

Thu14 night, near 35-30N / 39-30W: same.

Fri15, near 35-40N / 38W: 220@14-17g22, stray squalls to 30k, wind-chop 4-6', STRATEGY: same.

Fri15 night, near 35-50N / 36-30W: 240@15-20g25, more scattered squalls to 30k, wind-chop 4-7', STRATEGY: same.

Sat16, near 36N / 35W: ColdFRONT pases, wind either dies (and you motor toward Horta) or there may be some N-NNE wind N of FRONT, which forces you to continue sailing E until wind dies.

SUGGEST you request another forecast no later than Thu14, so we can fine tune passage of FRONT about Sat16, and make sure you're properly positioned for approach to Horta.

To make sure we have answered your questions regarding motoring...other than motoring for 1-2 days from Sun10-Mon11 night and maybe 1-2 days approaching Horta, you should have good wind for sailing.

If you have questions, let me know...Chris.