Weather Underground Forecast for Friday, September 16, 2011.
Cold conditions persist for the North-Central US on Friday as a ridge of high pressure builds over the Great Lakes. Flow around this system pulls cold air in from Canada, creating early Fall chill across the Great Lakes and Midwest. Overnight frost and freeze advisories have been issued as overnight lows will dip into the 20s across many areas of the North. The Midwest will see overnight lows drop into the 30s, while daytime highs will range in the upper 50s. The cold air will stretch eastward into the Northeast as a cold front shifts eastward and slowly moves off the East Coast. The system may kick up scattered showers as it lingers over Maine and the extreme Northeast.
Behind this system to the west, a trough of low pressure moves off the Southern Rockies and into the Southern Plains. This will kick up scattered showers and thunderstorms that will move into the Mississippi River Valley by evening. Some of these storms may turn severe with strong winds, large hail, and heavy downpours.
Meanwhile in the Northwest, a trough moves onshore from the Gulf of Alaska, which triggers a few light showers. This system will quickly move across the Northern Rockies, producing a few scattered rain showers. Temperatures in the Lower 48 states Thursday have ranged from a morning low of 19 degrees at International Falls, Minn. to a high of 98 degrees at Falfurrias, Texas