The Nation's Weather 12.16.09

By WEATHER UNDERGROUND (AP)

The storm system that pounded through the Great Lakes and Northeast was forecast to depart the region Wednesday, bringing a drying trend. Nevertheless, localized lake effect snow was expected to continue over southern and eastern shores of the Lakes but it should remain mostly on the light side. New snow accumulation was to remain under 3 or 4 inches.

Much colder air was expected to filter in after the system. Thus, temperatures were expected to drop at least 5 to 7 degrees below normal Wednesday and Thursday, in northern New England in particular.

High pressure was forecast to build into the South on Wednesday, leading to a drying trend across the Gulf States and Southeast. The only exception was likely to be the extreme southern states where an old front stalls. This old front combined with energy from the Intermountain West was expected to help produce potentially heavy rain and moderate to strong thunderstorms in southern Texas and Louisiana. Moreover, scattered showers and thunderstorms were also likely in southern Florida.

Out West, more rain and mountain snow was forecast across the Northwest, Northern Rockies and Northern California as a Pacific system gradually moved through. Then, a warming and drying trend was to take place Thursday as high pressure began building in the region.

Temperatures in the Lower 48 states Tuesday ranged from a low of -40 degrees at Jordan, Montana to a high of 86 degrees at Lakeland, Florida.