'Atmospheric River' To Dump Rain On South San Francisco

SAN FRANCISCO BAY AREA, CA — Weather forecasters are warning of an upcoming storm headed for the Bay Area which is expected to dump rain across the region beginning Wednesday. The storm system will include the winter's first "atmospheric river," which is a plume of deep moisture pointed at the region, according to the National Weather Service.

"Look for mostly dry conditions today before a storm system brings widespread rainfall and breezy to locally gusty winds during the day Wednesday to the North Bay and through the remainder of the region Wednesday night," the NWS said on Tuesday. "After another period of dry conditions, a third system is possible late in the upcoming weekend."

The storm could dump between 3 to 5 inches of rain in the coastal areas, and 1 to 2 inches inland, according to the NWS. Potentially hazardous winds are also forecast, with gusts up to 50 mph, prompting officials to issue a wind advisory for the region.

"As the front approaches southerly winds will pick up with higher elevation areas likely to see gusts over 40 mph at time," the NWS said. "Favored spots in the North and East Bay hills will likely see gusts over 50 mph."

As for South San Francisco in particular, here's what you can expect in the coming days:

Tuesday
Sunny, with a high near 60. North northeast wind 5 to 10 mph becoming west northwest in the afternoon.

Tuesday Night
A 10 percent chance of rain after 4am. Increasing clouds, with a low around 52. West northwest wind 6 to 13 mph becoming north northeast after midnight. Winds could gust as high as 18 mph.

Wednesday
A 50 percent chance of rain, mainly after 10am. Cloudy, with a high near 61. South southeast wind 6 to 11 mph. New precipitation amounts between a quarter and half of an inch possible.

Wednesday Night
Rain. Low around 55. Breezy, with a south southwest wind 26 to 28 mph, with gusts as high as 39 mph. Chance of precipitation is 80%. New precipitation amounts between 1 and 2 inches possible.

Thursday
Showers likely, mainly before 10am. Partly sunny, with a high near 59. South southeast wind 8 to 16 mph becoming southwest in the morning. Winds could gust as high as 23 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Thursday Night
Partly cloudy, with a low around 49.

Come Friday, drier weather is expected to return before another system returns as early as Sunday morning.

IMAGE 1: Widespread precipitation to the entire region is expected Wednesday into Thursday as a weak atmospheric river interacts with another frontal system as it pushes through / CREDIT: NWS

IMAGE 2: Breezy conditions can be expected at higher elevation locations for Wednesday and Wednesday night as a cold font approaches our region. / CREDIT: NWS