Old School Weather Forecasting

In a previous article, I wrote about using the website Windy.com to help with weather forecasting for sailors. In this article, I wanted to explain how you can obtain weather forecasts while cruising offshore and many miles from shore. A lot of you may already be familiar with weather fax, but for those who aren’t, read along and learn about this free resource.

There are five USGC stations that transmit weather fax at various times throughout the day. The frequencies and times for different areas can be found on THIS PDF. Because these transmissions are on frequencies in the Shortwave range, when the conditions are right they will bounce off the ionosphere, and sometimes repeatedly bounce off the ionosphere and the ground, causing the signal to travel up to thousands of miles. It is because of this bounce that weather fax has a real advantage while voyaging. Sure, you can buy a satellite phone and pay for service to download the GRIB files, but this can be very costly, and when sailing on a budget this may not be an option. This makes weather fax not only a viable option for predicting the weather but an appealing option.

To receive weather fax on your boat, or anywhere for that matter, all you need is a decent shortwave radio, a computer, and a cable to connect the speaker output of the radio to the microphone input of the computer. Here on Sail Before Sunset we use a laptop at the nav station and a shortwave radio that I have had for years now. This setup works very well for us. For an antenna, we connect to a long wire that runs the length of the boat, but you could also connect to the stanchions or the stays and it should work just fine. It will take a bit of tweaking to get the levels right because the speaker output of the radio will be higher than what the microphone input can handle, so keep the volume really low and open the microphone properties and turn the input down, along with any boost.

As for software, I’ve used several packages including SeaTTY and JWX, but I prefer JWX. It is written in Java, so you have to have that installed, but it has the best rendering and does a great job starting and stopping with each fax. You can then view and save each tab, as needed.

It seems the best frequency to receive on is 8682 kHz, especially during the day. Sometimes 4346 kHz comes in better, but this is not the rule. The other frequencies are good at various times.

So, don’t overlook this old school means of obtaining up to date weather information from the USGC. It works almost anywhere, is free (once you buy your equipment), and is the freshest weather data available. You will even receive satellite imagery of the areas you chose!

About Captain Tom

Over 10 years sailing and over 3500 miles under our keel. Was an engineer (EE) for over 30 years, then after moving into management, decided that the corporate world was no longer for me. Ran my wife's law office for 15 years and recently retired. Now we live aboard and sail the California coast, soon to leave for the Sea of Cortez.