.Severe weather and isolated flash flooding for the Great Lakes/OhioValley last evening; threat shifts to the Ohio and middle Mississippivalleys and Southern Plains Thursday......Warm to hot temperatures across the southern U.S.; chillier weatherspreading southeast from the northern Rockies/Plains...Showers and thunderstorms will continue to develop into the evening alongand ahead of a cold front now advancing eastward across Lower Michigan andthe Ohio Valley. Some of these storms may b...