Weather Underground Forecast for Friday, September 23, 2011.
A cold front continues triggering scattered showers and thunderstorms across the East on Friday. A low pressure system remains relatively stationary as it hovers over the Great Lakes and Northeast. A cold front extends southward from this system, lingering over the East Coast and triggering widespread scattered showers and thunderstorms. Strongest thunderstorms with periods of heavy rainfall will pop up across the Mid-Atlantic and Southeastern states, as additional moisture from the Gulf of Mexico supplies the system with more energy. Rainfall totals across the east will range from 0.5 to 1.5 inches, up to 2 inches likely in areas of severe thunderstorms.
Behind this system, a ridge of high pressure builds over the Plains and pushes cool air in from Canada. High temperatures on Friday will remain in the upper 50s across the Upper Midwest and lower 60s in the Midwest. Overnight lows will dip into the mid-40s, thus, frost and freeze advisories have not yet been issued.
Out West, a trough of low pressure dips southward from British Columbia and pushes some clouds into the Pacific Northwest. Rain showers will remain to the north, but cool and cloudy conditions are expected. The rest of the West Coast will see coastal clouds with plenty of sunshine across the interiors. Temperatures in the Lower 48 states Thursday have ranged from a morning low of 23 degrees at Kremmling, Colo. to a high of 104 degrees at Imperial, Calif.