The Weather Fax - SailNet Community

   Search Sailnet:

 forums  store  

Quick Menu
Boat Reviews  
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Hatches and Portlights
Interior And Galley
Marine Electronics
Other Items
Plumbing and Pumps
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here

Go Back   SailNet Community > Contributing Authors > Gear and Maintenance Articles
 Not a Member? 

Closed Thread
LinkBack Thread Tools
Old 10-20-1999
Join Date: Jan 2000
Posts: 162
Thanks: 0
Thanked 7 Times in 5 Posts
Rep Power: 16
Jim Sexton is on a distinguished road
The Weather Fax

Red sky at night a sailor's delight. This simple rhyme was probably the first weather forecasting tool you used. And it's a good one too, as red skies indicate dry air to the west and fair weather is on the way. But before you venture offshore, access to additional up-to-date weather information is imperative. For comprehensive, current and reliable information offshore, marine weather facsimile transmissions are the standard.

Weather fax transmissions are similar to the fax transmissions you receive via the telephone at home or work. The sender's fax machine scans a document and processes it into line after line of different colored dots-black, white and gray. The fax machine then translates the dots into tones, where a tone's pitch corresponds to the color of the dot. If you have ever listened to a fax transmission, you probably heard the warbling, high- and low-pitched tones. These tones are sent over the phone lines as each line is scanned. As your fax decoder receives the tones, it translates them back into dots and subsequently, characters on a sheet of paper and like magic you see what he sender placed into his fax machine.

Instead of using phone lines, a weather station's fax broadcasts over marine SSB frequencies. A demodulator cable allows sailors to connect a PC's serial port to the audio output of the SSB receiver to collect and decode the broadcast information automatically. By using a specialized software program, the broadcast weather fax information can be displayed on the computer screen and printed out or saved to the hard drive for reference.

The weather fax information broadcast typically consists of up to a dozen different kinds of synoptic weather charts that show the meteorological conditions over a given area. Approximately 70 stations around the world broadcast charts for their surroundings so with few exceptions, it is possible to get weather charts worldwide.

The interpretation of these charts is left to you so an understanding of marine weather is necessary to fully understand them. I would suggest that you take the weather course offered by the U.S. Power Squadron in your area first and to also read the weather chapter in Bowditch and the Mariner's Guide to Radiofacsimile Weather Charts by Dr. Joseph M. Bishop. The Weather Trainer by Starpath is an excellent tool for understanding and interpreting weather charts. This is a revolutionary, easy-to-use interactive program that you can use on your computer to learn weather forecasting.

There are several weather fax software programs available to you for about $180. Weather Fax for Windows and PC HF FAX version 8.0 for Windows. Both programs include a demodulator, software and instructional manual. The PC HF FAX program also includes an instructional tape and the program can also receive FEC, NAVTEX, Morse and SITOR.

For a complete listing of all HF weather fax frequencies and broadcast times check out:

You also may want to visit this site when you are surfing the web to see the GOES East IR - North and South America Satellite Weather Map in real time.

NOAA has interactive marine observation reports in real time at: where you can click on a buoy or CMAN station to get the current conditions for your area.

EDITOR'S NOTE: Also check the Useful Weather Web Sites article from SailNet Weather Advisor Bob Rice.

Quick reply to this message
Closed Thread

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

All times are GMT -4. The time now is 03:32 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) LLC 2000-2012

The store is owned and operated by a company independent of the forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.