Flash Floods Strike 7 Homes, Close Highway in Desert Area

A thunderstorm deluged the San Bernardino desert community of Morongo Valley with more than three inches of rain in as many hours Wednesday morning, and emergency crews braced for more problems today as subtropical moisture from Mexico hovered over inland mountain ranges and the desert.

The storm over Morongo Valley, which lies beyond the eastern slopes of the San Bernardino Mountains, flooded seven homes, undermined local roads, cut deep culverts through back yards and temporarily closed California 62 about 10 miles north of Interstate 10 because of mud and rock slides, said California Department of Forestry spokesman Bill Peters.

There were no injuries and no one was stranded, Peters said, “maybe through the good graces of four-wheel drive vehicles.”

Runoff from the downpour flooded roads in Desert Hot Springs to the south, even though it did not rain there, officials said.

The Riverside County Fire Department activated two swift-water rescue teams--positioning one in Desert Hot Springs and another in Palm Desert--but said they were not needed.

Weather forecasters said similar thunderstorms could strike today, from the San Bernardino Mountains southward down the Coachella Valley and eastern San Diego County to the Mexican border and eastward in Imperial County to Yuma.

Meteorologist James McCutcheon of Weatherdata, which provides weather information to The Times, said the slow-moving thunderheads were spawned by moisture from Tropical Storm Hilary off Baja California, combining with hot desert air that cools as it rises, resulting in condensation with a wallop.

Hilary is expected to weaken as it moves north, he said.

State forestry stations in local mountains reported varying amounts of rain and at least one lightning strike in the San Jacinto Wilderness Area above Palm Springs. A tree fire was extinguished by water drops from a helicopter.

Other isolated thunderstorms--some accompanied by frequent lightning--also struck in mountains of north central San Diego County.