Atmospheric river brings rainy weather, gusty winds back to Bay Area starting late Friday night

Another round of rain and gusty winds was set to batter the Bay Area beginning late Friday with the heaviest rain from the atmospheric river arriving Saturday, forecasters said.

The National Weather Service said the system moving over the Bay Area will bring light rainfall overnight Friday turning into moderate rain across the region during the day. 

KPIX First Alert Weather: Current conditions, alerts, maps for your area

Rainfall will be the greatest in the North Bay, with two to three inches likely in the coastal ranges and one to one-and-a-half inches in the valleys. The Santa Cruz Mountains could also see one to two inches, while other locations in the Bay Area will likely see half an inch or less.

According to KPIX chief meteorologist Paul Heggen, models indicate the arriving atmospheric river will rank as an AR-2 on the 1 to 5 scale.

The system will also bring more heavy snow to the Sierra, making travel to and from the mountains difficult beginning early Saturday morning. A Winter Storm Warning will be in effect through Saturday night, with one to two feet of snow and wind gusts over 50 mph expected.

King tides prompted a Coastal Flood Advisory for areas inside San Francisco Bay Friday from 10 a.m. to 1 p.m. Minor flooding was expected at flood-prone, low-lying areas near the bay shoreline, the weather service said. 

Winds are expected to be breezy to gusty along the coast through most of the gaps and passes across the region, as well as the hills, the weather service said.

On Friday, daytime highs will be mostly in the 50s in the Bay Area. Overnight lows will be in the upper 30s to lower 40s on the coast, in the 40s around the bay, and the upper 30s inland. A Frost Advisory for the Bay Area and Central Coast interior expired at 10 a.m.

Saturday, the high temps will creep higher and be mostly in the upper 50s to around 60. Overnight temperatures should remain seasonally warm as well with lows generally in the 40s. 

Showers will likely linger into Sunday morning and the region will see mostly clear skies until some more light rain on Wednesday, forecasters said.