The Nation's Weather 07.23.09

By WEATHER UNDERGROUND (AP)

Forecasters were calling for wet weather to persist over the Eastern US, while the West Coast was likely to remain unseasonably warm on Thursday.

A low pressure system was expected to continue tracking northeastward up the Ohio River Valley and toward the eastern Great Lakes. This system was forecast to create a cold front extending over the Mississippi River Valley, and was likely to create a warm front to lead the system in the east.

The cold front was expected to kick up light and scattered showers throughout the day, while the warm front was forecast to trigger scattered thunderstorm development over New England. Rainfall amounts between 1 to 2 inches was likely in areas of thunderstorm development, some of which may turn severe with strong winds, large hail, and possible tornado development. Below normal temperatures were expected to persist in the East with highs in the 70s in most areas.

Behind this system in the Plains, a small trough of low pressure that developed over the Central Rockies was forecast to continue moving through the Central Plains. Meteorologists called for it to bring another day of scattered showers and thunderstorms that may turn severe.

Further west, a strong ridge of high pressure was expected to hover over the West Coast and allow for another day of extremely warm temperatures. Heat advisories remained in effect for the Pacific Northwest with highs in the 80s and 90s, while southern California was expected to surpass 100 degrees again on Thursday.

Temperatures in the Lower 48 states Wednesday ranged from a low of 37 degrees at Wolf Creek Pass, Colo to a high of 111 degrees at Imperial, Calif.