模式:

NAM: North American Mesoscale Forecast System "NOAA"

更新:
4 times per day, from 0:00, 06:00, 12:00 and 18:00 UTC
格林尼治平时:
12:00 UTC = 20:00 北京时间
Resolution:
32km
参量:
锋面
海平面气压(百帕,实线)
描述:
850百帕等相当位温线(彩色虚线)

相当位温是从850百帕比湿(湿空气中水汽的质量同湿空气总质量之比)及温度算出。 从这幅图上人们比从“RH 700 hPa”图或其它图上更容易看出锋面位置。

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://zh.wikipedia.org/wiki/數值天氣預報(as of Feb. 9, 2010, 20:50 UTC).