A cold front brings gusty winds to cities
After a warm weekend that included some lightning strikes across Santa Cruz and Santa Clara counties on Saturday, weather in the Bay Area is set to fluctuate over the next few days.
Temperatures Monday are expected to be a few degrees above normal, with highs in the 60s on the coast, 70s to 80s across the Gulf, and 80s to 90s inland. A cold front will increase winds Monday evening and lower high temperatures on Tuesday by about 5 to 10 degrees.
Tuesday and Wednesday will see near-normal temperatures before there is a slight increase in temperatures on Thursday and Friday.
Monday is windy
Weather models indicate that a cold front will boost winds along the San Francisco Peninsula on Monday afternoon.
Baron/LynxAs the jet stream begins to strengthen across Canada in September, Northern California is often on the outskirts of weather makers crossing British Columbia in early fall. This will be the case Monday and Tuesday, as a weak cold front — associated with a low pressure system in British Columbia — moves through the Bay Area.
This cold front won’t bring any rain to Northern California, but it will bring gusty winds to the Bay Area between Monday afternoon and early Tuesday. Typical wind-prone areas such as the San Bruno Gap between Daly City and San Francisco International Airport could see wind gusts up to 35 mph Monday evening.
Cold air behind the cold front will bring temperatures Tuesday about 5 degrees below normal, the coldest of the week. Highs will be in the mid-60s along the coast and near 80 degrees inland.
As for the rest of the week, temperatures will be close to normal, with 60°C on the coast, 70°C near the Gulf, and 80°C inland.
Monday collapse
San Francisco: The morning clouds are expected to clear at midday, turning the afternoon into mostly sunny. Temperatures will reach the mid to upper 60s in the Sunset and Richmond areas and mid 70s in the Mission District, South of Market and downtown.
An approaching cold front will bring breezes during the late afternoon and evening, with sustained winds of 15 to 20 mph and gusts up to 30 mph along Ocean Beach and in Twin Peaks, Ingleside and Bernal Heights.
Overnight lows will drop to the mid 50s, with occasional wind gusts up to 25 mph continuing.
East Bay: A warm day awaits for the Interstate 680 corridor, with temperatures reaching the upper 80s in Concord, Dublin and Livermore. Antioch should get into the lower 90s. Temperatures will cool quickly when winds reach 20 to 25 mph in the evening. Overnight lows will fall into the mid 50s, with scattered clouds extending all the way east of the Caldecott Tunnel Tuesday morning.
High temperatures will be in the mid to upper 70s in Richmond, Berkeley, Oakland, Hayward and Fremont, with morning clouds disappearing with a sunny afternoon. Evening wind gusts of up to 20 mph are possible in Hayward and Fremont. Overnight lows will drop to the mid 50s, with some scattered clouds spreading inland by Tuesday morning.
North Bay: Scattered morning clouds will part for a mainly sunny day over the North Bay, with temperatures 5 degrees above seasonally average. Vacaville will be the hottest spot in the mid-90s, while Santa Rosa, Napa and Sonoma will reach the upper 80s. San Rafael, Petaluma and Vallejo will be in the lower mid 80’s. Tiburon and Sausalito would be in the mid to high 70’s.
Evening winds are expected to reach 15 to 25 mph in the Petaluma Valley and along the Delta. Overnight lows will drop to the mid 50s in Marin, Sonoma and Napa counties and the upper 50s in Solano County.
Pacific coast and peninsula: Despite sunny skies and seasonal temperatures, a windy afternoon will make conditions even cooler. A stiff evening breeze will blow over the San Bruno Gap and bring wind gusts up to 30 mph to Daly City, San Bruno, South San Francisco and Millbrae.
Highs will peak around 2 PM in Daly City in the upper 60s. Temperatures will be warmer south along Highway 101, with mid 70s in San Mateo and upper 70s in Redwood City. In Pacifica, El Grenada and Half Moon Bay, highs will be in the mid 60s. Gusty winds during the night may stir up the atmosphere and prevent fog from condensing significantly. Lows will be in the mid-50s in San Mateo County.
South Bay and Santa Cruz: It’s expected to be a seasonal day in the Santa Clara Valley, with highs in the lower to mid 80s in San Jose, Sunnyvale and Cupertino. Evening winds could reach 20 mph, with overnight lows dropping into the upper 50s.
Skies are expected to remain mostly sunny in Santa Cruz, Scotts Valley and Boulder Creek on Monday, with highs in the mid 70s. The overnight lows would drop into the mid-50s.
Contact Anthony Edwards: anthony.edwards@sfchronicle.com
