One of the forecasting tools the StormTeam uses is a feature called PrecisionCast.
What is PrecisionCast and what does it mean?
Twice a day weather data from all over North America is input into super computers at the National Weather Service s forecasting headquarters outside of Washington, DC. The computers use the data to run numerical models of the atmosphere. These are computer simulations of the atmosphere that attempt to forecast what the weather will be doing over time. These various computer models form the basis of the PrecisionCast.
The PrecisionCast models can be used to show forecasts of a great variety of atmospheric variables like pressure, temperature, moisture, and precipitation. In order to make the graphics a bit more viewer friendly we generally limit the highlighted features to highs, lows, fronts and moisture levels. In particular, the areas that are shown as shades of gray to white indicate moderate levels of moisture, where typically one might find clouds and maybe a slight chance of precipitation. Green areas indicate higher moisture levels and therefore a better chance of precipitation. And yellow and orange shades show areas that might expect heavier precipitation, or at least a very high probability of precipitation. (There is a key that shows this along the bottom of the screen.) So when you watch the PrecisionCast you should watch not only the more familiar lows, highs, and fronts; but also how the areas of white, green or yellow and orange move and develop over time. To help indicate the passage of time, a clock is present in the upper left-hand corner.
It is important to remember that the PrecisionCast is only a forecast. Even though computer forecast models continue to improve, there is really no way to precisely predict all the complex features of the atmosphere. Indeed, one of the challenges of modern forecasting is determining which if any of the many different computer models has a better handle on the atmosphere. Another challenge is determining what all the lines and numbers mean in terms of actual weather. Hopefully the PrecisionCast will help us present the latest weather technology to the viewers in a colorful and easily comprehensible manner.