A National Weather Service flash-flood watch for the mountains and deserts is scheduled to remain in effect from noon until 8 p.m. Forecasters said thunderstorms would likely develop Friday afternoon.
“A slow-moving low-pressure system centered near Point Conception will maintain moisture and instability across portions of Southern California today,'' according to the weather service. “Slow moving thunderstorms [Friday] afternoon and early evening have the potential to produce locally heavy rainfall with flash flooding."
Forecasters said the valleys would have a slight chance of afternoon showers and thunderstorms, but they were not included under the flash flood watch.
A second low-pressure trough could contain enough moisture for more rain into early next week.
Later next week, easterly flow between the low-pressure trough and high-pressure building over the Great Basin is expected to bring drier, warmer weather.