The first of three expected storms will hit the San Diego region Monday, prompting the National Weather Service to issue a flash flood watch for this afternoon through this evening.
The NWS forecasts one to two inches of rain throughout tonight near the coast and between two and four inches in the foothills and mountains, except on some southwest-facing slopes, which could receive up to eight inches.
NWS Forecaster Tina Stall says today's storm will be a soaker.
"It's dropping some pretty heavy rain," Stall says.
The flash flood threat resulting from the rainfall “will be highest this evening. Mud slides will be possible, especially in recent burn areas,” according to the NWS advisory.
Stall says the storm will also bring windy conditions.
"Because of the jet stream's right over us, it's a very strong one," Stall says. "So those strong winds aloft will get mixed down to the surface and create windy conditions at surface as well."
Through the week, three to six inches of rain could fall in a series of storms in the inland valleys, with more in the mountains.
The precipitation will move out on Tuesday, but more will arrive late that night, with rain expected Wednesday through Saturday.
Each storm will carry a chance of flash flooding, and the possibility of flooding will grow as the week wears on and the ground becomes saturated.
San Diego lifeguards plan to activate their swiftwater rescue units, while Cal Fire will have bulldozers, four-wheel drive vehicles and 177 firefighters available to deal with possible flood situations.
Many area fire and lifeguard stations have made sandbags available the past few days, and many have already been taken by property and business owners.
A high surf advisory and high wind advisory are also in effect. Gusts are expected to be as high as 30 mph.