ccFlash flood warnings were in effect for central LA County, north-central San Bernardino County, and Riverside County.
A flash flood watch was in effect in San Bernardino County and Riverside County, where flash flooding was reported in San Timoteo Canyon between Redlands and Moreno Valley. Cars were stuck in flood waters along San Timoteo Canyon Roads, according to the National Weather Service.
In Moreno Valley, about 20 Riverside County firefighters were attempting to a "water rescue" of people stuck in a car with the windows rolled up at the intersection of Oliver Street and Cactus Avenue (map).
Flash flooding in Moreno Valley sent mud cascading into homes near Oliver Street and Cactus Avenue, where some residents' swimming pools have been filled with muddy water and some cars parked on the street were pushed by the mud flow, according to City News Service.
The flooding was occurring about 2 miles north of Lake Perris. It was not immediately clear how many homes were affected.
About 8 miles north of there, another water rescue brought a separate group of 20 county firefighters to try to reach a minivan and small truck stuck in what appeared to be a sinkhole. That rescue was taking place near San Timoteo Canyon and Live Oak Canyon roads (map).
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Both incidents were reported at about 3 p.m.
Meanwhile, in the Antelope Valley, the Los Angeles County Fire Department had responded to multiple grass and brush fires caused by lightning.
Heavy rainfall closed East Palm Canyon Drive between Golf Club and Cathedral Canyon drives in Cathedral City until further notice. A levee at Eagle Canyon Dam broke, Cathedral City spokesman Allen Howe told City News Service.
Officials warned motorists not to drive their cars where water covers the roadway because water depth may be deceptive.
The wet weather is thanks, in part, to an unstable monsoon flow working up its way up from the south.
Hurricane Ileana churning near Cabo in Baja California will bring high surf to Ventura, LA and Orange County coasts, and sets could reach 10 feet in some areas.
"That in combination with the very nasty rip current is going to make what is usually the last weekend before people settle back into their school and work schedules, it’s going to make it very dangerous down there," said NBC4’s forecaster Fritz Coleman. "Keep your eyes on the kids and keep your eyes on the pets."
Thursday’s temperatures varied from 76 degrees at the coast to 87 degrees in the high desert to 94 degrees in the valleys. The warm temps averaged about 4 degrees cooler than Wednesday.
Clouds and fog will move in Thursday night, giving way to a cooling trend that is expected to continue into the weekend.