The National Weather Service issued a flash flood warning through 5:30 p.m. Monday for areas along Highway 74 south of the Cranston Fire burn scar and warned that the rapid rainfall could cause dangerous debris flows.
Forecasters said the area could receive as much as an inch of rain and saturate areas scorched by the fire last summer in the San Jacinto State Park.
“Move away from recently burned areas. Life-threatening flooding of creeks, roads and normally dry arroyos is likely,” the NWS said.
The agency also said small hail and gusty winds were also possible in the mountain areas.
The Riverside County Fire Department advised anyone who encountered a flooded road to turn around and not try to drive on it.
Elsewhere, flooding from overnight thunderstorms prompted the closure of North Indian Canyon Drive in Palm Springs, police said.
The road was closed at the wash due to “water over the roadway,” according to Palm Springs police.
Police did not say when they expect North Indian Canyon Drive to be reopened. The road is the main throughway connecting Palm Springs to Interstate 10 and Desert Hot Springs.
Thunderstorms moved into the region Sunday night from Arizona, dumping nearly an inch of rain in Palm Springs in the last 24 hours, according to preliminary data from the National Whether Service. Idyllwild saw over half an inch of rain in the same time period.
A flash flood watch will continue to be in effect until 8 p.m. for the Coachella Valley and the Riverside County mountains.
Forecasters said thunderstorms would mainly affect mountain crests and the high desert and dissipate by sunset.