Weather Underground Forecast for Wednesday, August 22, 2012.
Active weather will continue across the South on Wednesday. A frontal boundary lingers over northern Florida and the Gulf Coast, producing more heavy rainfall with strong thunderstorms. This system will continue pulling moisture and energy in from the Gulf of Mexico, allowing for some storms to turn severe with strong and damaging winds and periods of heavy rain. Behind this system, high pressure dominates the Plains, Mississippi River Valley, and Eastern US. This keeps moisture out of the Eastern third of the nation and brings sunny and dry conditions to the region on Wednesday. High temperatures should remain cooler with highs ranging in the 70s and 80s.
Further west, a trough of low pressure over the Northern Rockies will advance eastward and into the High Plains. This pushes showers and thunderstorms eastward throughout the day, bringing active weather to the North-Central US. Showers and thunderstorms will develop in the Dakotas in the morning, moving into the Upper Midwest by evening. Severe storms are not likely in these areas, but strong and gusty winds may develop.
Further West, monsoonal moisture remains over the Southwest, Great Basin, as well as the Central and Southern Rockies. This kicks up more widespread showers and thunderstorms. At the same time, prevailing hot and dry conditions will maintain dangerous fire weather conditions across most of the Western states. Temperatures in the Lower 48 states Tuesday have ranged from a morning low of 33 degrees at West Yellowstone, Mont. to a high of 102 degrees at Bullhead City, Ariz.