Late Wednesday night, Ventura and Santa Barbara counties were under flash flood warnings and that remained in effect through 12:30 a.m. Thursday. After the warnings expire, those two counties will return to flash flood watches.
As for Los Angeles and San Luis Obispo counties, those counties have been under flash flood watches since Tuesday night and is expected to stay that way through 4 a.m. Friday, December 22. The watch is set to raise awareness for possible flooding of roads, creeks and streams.
Flash flooding will also be a risk in recently burned areas. There will also be a strong potential for rock slide and mudslide activity in canyon and mountain roadways.
Forecasters estimated that much of the Los Angeles area could receive 2 to 4 inches of rain during the "atmospheric river" event accompanying the second storm system, with 4 to 8 inches possible on south-facing foothill areas and coastal slopes. Rainfall rates of 0.3 to 0.6 inches per hour are expected in some areas, but if thunderstorms develop, some areas could see rain falling at a rate of 1 inch per hour.
By Wednesday evening 1.16 inches of rain was reported in Culver City, 1.68 inches in Northridge and 0.90 in Fillmore.
"A stronger storm will bring several hours of steady moderate to heavy rain and gusty winds Wednesday and Thursday, with threats for flooding and thunderstorms," forecasters said.
Conditions are expected to dry out on Friday, although gusting northwest winds are expected to linger into Saturday.
Los Angeles County Lifeguards warned people to exercise caution if they visit the beach.
City News Service contributed to this report