Model:

Euro4: Global weather forecast model from the "UK MetOffice, North Atlantic European Model"

Updated:
4 times per day, from 0:00, 05:00, 11:00 and 17:00 UTC
Greenwich Mean Time:
12:00 UTC = 12:00 GMT
Resolution:
0.04° x 0.04°
Parameter:
Vertical velocity at 700 hPa in hPa/h
Description:
The vertical movement of air is associated with cloud formation, precipitation, type of precipitation (negative velocity or rising air motion) or the reduction of clouds, dry an sunny weather (positive velocity or falling air motion). The vertical velocity is the result of vorticity advection and temperature advection.
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).