Analyzing and predicting the weather at sea is an ongoing process of gathering, analyzing, and displaying information. To ensure this process is fruitful and productive we use a concept called the "weather triangle." The weather triangle happens when you use three independent sources for weather information, and use them to verify each other. These three sources are:
In addition to gathering and using weather information, we need to verify that information is complete as well as accurate. The weather triangle assists with this need as well. Former President Ronald Reagan is supposed to have once said: "Trust but verify," and regardless of your party affiliation, this is a useful slogan in both politics and weather!
What are we trusting and yet verifying? We trust official analyses and forecasts, as well as our onboard instruments such as the barometer and the anemometer, but we are verifying information from these sources with actual observations and human senses. Our verification is assisted by satellite imagery, which can be captured on board directly by using systems such as SeaStation 2000 (www.ocens.com), Weatherfax, or via Internet connection.
Here is an example of how the weather triangle works: say we have departed Annapolis, MD, in October and are heading to Bermuda. On our second day out we observe a swell building from the south. The swell period (the time in seconds between successive crests) is increasing as the day progresses; it starts with a six to eight-second period and by evening is 12 to14 seconds and the seas are building in height. What is happening? Well, we have one piece of the weather triangle established—the on-scene observation—as we have detected a swell and noted its changing period.
- On-Scene Observations
- Official Analyses and Forecasts
- Satellite Imagery
Satellite imagery, like this high-resolution image from www.ocens.com, makes up the third side of the weather triangle. |
In addition to gathering and using weather information, we need to verify that information is complete as well as accurate. The weather triangle assists with this need as well. Former President Ronald Reagan is supposed to have once said: "Trust but verify," and regardless of your party affiliation, this is a useful slogan in both politics and weather!
What are we trusting and yet verifying? We trust official analyses and forecasts, as well as our onboard instruments such as the barometer and the anemometer, but we are verifying information from these sources with actual observations and human senses. Our verification is assisted by satellite imagery, which can be captured on board directly by using systems such as SeaStation 2000 (www.ocens.com), Weatherfax, or via Internet connection.
Here is an example of how the weather triangle works: say we have departed Annapolis, MD, in October and are heading to Bermuda. On our second day out we observe a swell building from the south. The swell period (the time in seconds between successive crests) is increasing as the day progresses; it starts with a six to eight-second period and by evening is 12 to14 seconds and the seas are building in height. What is happening? Well, we have one piece of the weather triangle established—the on-scene observation—as we have detected a swell and noted its changing period.
The second side of the weather triangle comes from official forecasts. | |