Rain, wind to mark Bay Area’s coolest day since February

After scattered showers snapped the Bay Area’s dry streak Tuesday, another chance of rain is forecast Wednesday, this time more widespread and accompanied by gusty wind.

Unlike Tuesday’s showers, which were sporadic in organization and duration, Wednesday’s rain chances stem from a more organized — albeit weak — cold front.

The morning will be partly to mostly cloudy, with drizzle and scattered light rain showers in the North Bay, San Francisco and the Peninsula. A dry break is possible in the afternoon, but a cold front will increase rain chances as it moves across the area from northwest to southeast from the late afternoon through the evening.

Steady light rain is expected to reach San Francisco and Oakland during the evening commute, and San Jose around 10 p.m. 

“Slick roadways can be expected due to the dry spell that has allowed oil to accumulate,” the National Weather Service said.

Rainfall totals are expected to range from a tenth to a quarter of an inch in the North Bay, East Bay and the San Francisco Peninsula, with localized totals up to a half-inch in the hills. San Francisco and Oakland will probably end up on the lower side of that range. San Jose probably won’t get more than a tenth of an inch.

Breezy conditions will pick up as the front passes through. Southwest gusts of 20 to 30 mph are predicted ahead of the front, with northwest gusts up to 25 mph behind it.

Wednesday is expected to be the coolest day since February in San Francisco, Oakland, Santa Rosa, and Napa. Highs will only be in the upper 50s to mid-60s. Thursday morning will be noticeably chilly behind the cold front. Temperatures will be in the upper 30s to mid-40s in the North Bay, and the mid- to upper 40s elsewhere, including San Francisco.

Dry weather will prevail by midmorning Thursday with a warming trend anticipated Friday through the weekend, pushing high temperatures back into the 70s to mid-80s.

San Francisco: Showers are possible during the morning commute, but a dry break is possible around lunch. Gusts will pick up in the afternoon, reaching 20 to 25 mph downtown and up to 30 mph near the water and atop Twin Peaks. Steady light to moderate rain is expected in the evening, before transitioning to showers overnight. Highs will be in the upper 50s to low 60s west of Twin Peaks and the mid-60s to the east, including downtown. Lows will be in the upper 40s to low 50s.

North Bay: Sonoma County could contend with showers at any hour, while Marin, Napa and Solano appear to have two distinct chances of rain: midmorning and late afternoon. After morning showers, there may be a few hours of sun between the clouds before a cold front approaches. It’ll bring gusts up to 25 mph before the rain starts in the late afternoon and continues through the evening. A few showers may linger overnight. It will be the coolest day since February, with highs in the upper 50s to low 60s and lows in the upper 30s to low 40s. 

East Bay: A stray shower is possible in the morning, but the best chance of rain will come in the late afternoon through the evening. Totals will probably be around a tenth of an inch in Richmond, Berkeley, Oakland and Alameda, with lesser amounts in Antioch, Concord, Walnut Creek, the Tri-Valley and Fremont. The rain will be accompanied by wind gusts up to 25 mph from the southwest during the day, then from the northwest behind the cold front in the evening. Highs will be in the low 60s in Contra Costa County and the mid-60s in Alameda County, warmest around Livermore. Lows will be in the mid- to upper 40s.

Pacific Coast and Peninsula: It’ll be a breezy day, with southwest gusts up to 30 mph along the coast and 20 mph along the Highway 101 corridor. Winds will switch direction out of the northwest behind the cold front in the evening, gusting up to 25 mph. Scattered showers are possible in the morning, but the best chance of precipitation will come in the evening as a cold front moves through. Most of it will come from light to moderate rain over the course of two hours, dropping a tenth of an inch or so, with higher totals along the coast. Highs will be in the upper 50s to mid-60s, with lows in the mid- to upper 40s.

South Bay and Santa Cruz: The South Bay will be the warmest part of the Bay Area, with highs in the mid- to upper 60s. Santa Cruz County will stay cooler, in the low 60s. Rain chances are greatest after the evening commute, though showers probably won’t add up to more than a tenth of an inch in the Santa Clara Valley. Up to a quarter of an inch could fall in the Santa Cruz Mountains. Breezy northwest winds behind the front will bring gusts up to 20 mph overnight. Lows will be in the mid- to upper 40s.