Weather Underground Forecast for Wednesday, August 08, 2012.

Active weather is expected to continue over the East Coast and portions of the Midwest Wednesday. A cold front will continue to advance eastward through the East Coast and southward across the Ohio Valley and Mississippi Valley, producing widely scattered showers and thunderstorms. Heavy rain along with strong to severe thunderstorms will be possible over parts of the Upper Midwest especially. Cooler air will filter in after the cold front, bringing temperatures down 10 to 15 degrees Thursday to Friday across much of the Midwest and parts of the Northeast.

Farther south, an old frontal boundary from the Mid-Atlantic to the Plains combined with abundant Gulf moisture will keep scattered showers and thunderstorms going across the Mid-Atlantic, Southeast and portions of the Southern Plains and lower Mississippi Valley. Heavier precipitation can be expected over the coastal region.

Elsewhere, unsettled weather will persist over the Four Corners region and parts of the Southern High Plains Wednesday as monsoonal flow continues to creep upward. In the Northwest, an approaching cold front will keep light rain and showers going over Washington.

Another hot day is in store for the Southwest and Rockies under a strong ridge of high pressure. Temperatures in the Lower 48 states Tuesday have ranged from a morning low of 33 degrees at West Yellowstone, Mont. to a high of 109 degrees at Needles, Calif.