The storms were likely to cause flooding in the Mississippi Valley and could become severe, producing strong winds, heavy rains, hail and possible tornadoes.
An excessive heat warning was issued for the southern Plains because of high pressure hovering over the region and bringing up hot air from southern Texas. Temperatures were likely to surpass 100 degrees in many areas.
Wet weather was forecast for the Southwest, which is in monsoon season. Also, the remnants of Dolly were likely to cause widespread showers and thunderstorms in the region, leading to concerns about flooding.
Increasingly cloudy skies were forecast over the Pacific Northwest as a low pressure system over the Gulf of Alaska pushes a cold front into the region. Cooler temperatures and light scattered showers were forecast, though California was expected to remain warm and dry.
Temperatures in the Lower 48 states on Friday ranged from a low of 32 degrees at Polebridge, Mont., to a high of 121 degrees at Death Valley, Calif.
