At Marine Weather Center, a client recently asked why the computer model forecast predicted small seas on the windward side of Saint-Martin, when what was really happening were strong winds and large seas. The answer had everything to do with how weather models are designed, how they work and how they don’t.
Weather forecast models are ubiquitous for good reason: They provide precise forecasts for weather information, such as wind, waves, temperature and precipitation that we’re looking for, at precise times and locations—or so it would seem. But weather models have limitations, and understanding these limitations will help you better interpret their forecasts and be a safer boater.
WHAT IS A WEATHER MODEL?
Weather models break the Earth down into grid boxes, with each grid box representing a specific area on Earth’s surface and the atmosphere above. Forecast models start by approximating the current state of the atmosphere, using recent observations from satellites, airplanes, weather balloons,
