Administrative messages from National Meteorlogical Center. Continental U.S. U.S. Surface Plot - Chart shows surface high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure. Outflow boundaries, the boundaries of thunderstorm outflow air, which may travel far from the original storms and could contribute to new storm development, are sometimes noted. See the section below for detailed information on Lifted Indices.
Many indices can be useful for predicting severe weather.
The importance of one particular index varies from situation to situation. For detailed information on SKEW-T's, see below . Current Total Totals Index - This US map is produced every morning and evening from upper air data. This index determines the potential for thunderstorms and is very helpful in diagnosing the difference between weak and strong thunderstorms. 44 - Spotty, usually light thunderstorm.