Model:

Updated:

2 times per day, from 10:00 and 23:00 UTC

Greenwich Mean Time:

12:00 UTC = 07:00 EST

Resolution:

0.25° x 0.25°

Parameter:

Vertical velocity at 925 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.

GME:

GME is the first operational weather forecast model which uses an icosahedral-hexagonal grid covering the globe. In comparison to traditional grid structures like latitude-longitude grids the icosahedral-hexagonal grid offers the advantage of a rather small variability of the area of the grid elements. Moreover, the notorious "pole-problem" of the latitude-longitude grid does not exist in the GME grid.

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).