Heat wave to bake Bay Area early this week
A late May heat wave could push some parts of the Bay Area close to 100 degrees in the coming days, baking the region's landscape with some of the hottest temperatures so far of 2022 and priming the area for a tinder-dry fire season.
High temperatures are expected to climb 5 to 20 degrees above normal today and Wednesday for much of the Bay Area — part of a blast of hot weather that prompted a heat advisory for the entire Central Valley and a red flag warning for a broad swath of Northern California stretching from Vallejo to Redding.
Inland portions of the East Bay, including Discovery Bay and Livermore, could see temperatures reach into the high 90s and low 100s today and Wednesday, said Matt Mehle, a National Weather Service meteorologist. Highs in the Santa Clara Valley are expected to top out in the high 90s, including in San Jose and Gilroy.
Temperatures should only climb into the low 80s in Oakland — still 10-12 degrees above normal — while reaching the mid-70s in San Francisco.
The hot weather means that the Bay Area can expect elevated fire conditions early this week, Mehle said. Humidity levels could drop into the single digits in parts of the North Bay and the East Bay, while winds could gust 20 to 30 mph in parts of the East Bay hills, and in Santa Clara County.
Forecasters have yet to issue red flag warnings in the Bay Area for those days, because recent late-spring storms have helped pump enough moisture into the region's vegetation to avoid the threat of major fires, Mehle said.
That should soon change, he added. This heat wave should dry out the area's grasses, shrubs and trees — likely leaving dangerous fire conditions ahead in June.
“After this, we'll be into fire season,” Mehle said. “This round of hot and dry weather is basically going to help erase any moisture we had from the late spring rains.”
The temperatures mark some of the hottest so far of 2022. San Jose, for example, has only recorded one day of 90-degree temperatures so far this year, according to the National Weather Service. The city reached 94 degrees April 7 — just a hair higher than the temperatures forecasted during this week's heat wave.
The toasty forecast comes as firefighters wrapped up work on two fires that prompted evacuations over the weekend in Solano and Mendocino counties.
Firefighters working on the Quail Fire outside Vacaville reported 90% containment early Monday morning, according to Cal Fire. The 136-acre blaze prompted several residents to flee their houses Saturday afternoon, although those evacuation orders were downgraded as crews got a handle on the fire. No cause has been announced for the blaze.
Also, the 36-acre Owens Fire was fully contained early Monday morning — ending a three-day fight to protect properties near Point Arena in Mendocino County, about 100 miles north of San Francisco. The cause of that fire also remains under investigation.
Relief should arrive by Thursday, when the mass of high pressure over the Bay Area moves out and cooler temperatures return. The more moderate weather should continue into the Memorial Day weekend — meaning much of the Bay Area can expect highs in the 70s by Friday and Saturday.
“It's actually going to be really nice,” said Mehle of the coming holiday weekend. “The temperatures will be much cooler and closer to seasonal averages.”