Fire managers worried Tuesday that lightning could spark more wildfires in the West, where hundreds of square miles of land have been blackened, as thunderstorms also threatened flash flooding in burned-over areas.
A flash flood watch was in effect for parts of western Nevada and the Sierra Nevada range, with forecasters warning of the potential for extensive runoff in areas stripped of vegetation by the wildfire that destroyed at least 254 homes south of Lake Tahoe and by a large blaze southwest of Reno.