Winter Blast Will Send Bay Area Temps Into The 20s: See Windchill Chart

SAN FRANCISCO — Winter weather is set to chill Northern California this weekend, plunging overnight temperatures into the 30s and low 40s for much of the Bay Area with an added wind chill that will bring some areas down into the 20s. While the specifics vary by area, a colder trend will be universal across the region.

After a little rain Saturday, mostly clear skies are in the forecast until Tuesday.

"Temperatures will start falling into Saturday morning, with the coldest lows on Sunday and Monday morning," NWS Bay Area forecasters wrote Friday. "Inland valleys are expected to drop into the upper 20s to mid-30s, with temperatures in the mid-20s possible in the coldest spots. Meanwhile, the Bayshore and Pacific coastal regions see lows ranging from the upper 30s to mid-40s."

Forecasters expect afternoon highs will dip into the mid-50s at lower elevations and drop down into the 40s at higher elevations, with chilly temperatures likely to stick around well into next week.

For areas of the Central Coast, the National Weather Service issued a frost advisory through at least Saturday morning. In a briefing Thursday, forecasters noted additional frost advisories or freeze warnings could be issued for areas of the North Bay, East Bay, South Bay and Peninsula.

In the Sierra, forecasters are preparing for another healthy dose of snow over the weekend, adding to accumulations from recent days. Researchers at the UC Berkeley Central Sierra Snow Lab on Donner Summit measured a foot of fresh snow between Tuesday and Thursday mornings, with models suggesting another foot or two possible over the weekend.

The lab will host an update on snowpack conditions and share other updates on Thursday, respecting several feet of snow to fall over the next week. A winter storm warning will be in place for much of the Sierra between Saturday and Sunday mornings.

New outlooks from the Climate Prediction Center favor a cooler, wetter trend lingering in California and much of the U.S. through at least the middle of January.