As cooler, cloudier conditions settle over much of Southern California, the heaviest rainfall, along with a chance of thunderstorms and mountain snow, will be overnight Wednesday through Thursday morning, the National Weather Service forecasts.  

The late season storm is expected to sweep through Santa Barbara and Ventura counties late in the evening with Los Angeles County seeing the greatest chance for rain very early.

Rainfall of a half inch to an inch is forecast in coastal and valley regions, with mountains and foothills seeing 1-2 inches.  

“The coastal sections of LA County will likely see a little less rainfall than the (Ventura County) coast, but south facing slopes should see similar amounts,” the NWS said.  

Snowfall is expected at elevations of 4,500-5,000 feet, with a 20-40% chance of up to an inch of snow falling over the Grapevine. At elevations of 6,000 feet and higher, up to 6 inches is expected with a 20-40% of 1 foot of snow in isolated areas.  

Motorists should be on the lookout for minor roadway flooding and hazardous conditions due to slick streets. Above 5,000 feet, winter driving conditions should be expected.   

As the threat of rain moves out of the region Thursday night, skies are expected to remain mostly clear as a general warming trend takes hold Friday through Monday. 

Inland areas can expect temperatures in the 70s Sunday through Monday, with temps on the coast remaining cooler due to the marine influence.