Model:

Ανανέωση:

4 times per day, from 00:00, 06:00, 12:00 and 18:00 UTC

Μέσος χρόνος Γκρίνουιτς:

12:00 UTC = 14:00 EET

Resolution:

0.25° x 0.25°

Παράμετρος:

Wind at 900 hPa

Description:

This map shows the average wind vector at 900 hPa for every modeled gridpoint (ca. 80 km). Based on the average SLP of about 1010 hPa the equivalent pressure altitude for 900 hPa would be at about 900m a.s.l. (ca. 3000 ft). This map is very useful for gliders and hang-gliders, if their airfield or starting pad is at a low altitude. (wind-converter)

GDAS

The Global Data Assimilation System (GDAS) is the system used by the National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) model to place observations into a gridded model space for the purpose of starting, or initializing, weather forecasts with observed data. GDAS adds the following types of observations to a gridded, 3-D, model space: surface observations, balloon data, wind profiler data, aircraft reports, buoy observations, radar observations, and satellite observations.

NWP:

Numerical weather prediction uses current weather conditions as input into mathematical models of the atmosphere to predict the weather. Although the first efforts to accomplish this were done in the 1920s, it wasn't until the advent of the computer and computer simulation that it was feasible to do in real-time. Manipulating the huge datasets and performing the complex calculations necessary to do this on a resolution fine enough to make the results useful requires the use of some of the most powerful supercomputers in the world. A number of forecast models, both global and regional in scale, are run to help create forecasts for nations worldwide. Use of model ensemble forecasts helps to define the forecast uncertainty and extend weather forecasting farther into the future than would otherwise be possible.

Wikipedia, Numerical weather prediction, http://en.wikipedia.org/wiki/Numerical_weather_prediction(as of Feb. 9, 2010, 20:50 UTC).