Spare the Air alert issued
The onset of a heat wave that's just passing by began to arrive Thursday in the Bay Area, and it didn't feel entirely like the usual ones that hang around a long time.
“There is an onshore component, and there aren't the offshore winds we often get,” said National Weather Service meteorologist Sarah McCorkle. “So there's a bit more moisture in the air that you might feel.”
There also will be some pollution caused by the high-pressure build that has caused temperatures to go up, officials said. The high pressure tends to trap fine particulate matter, which causes smog to build. The Bay Area Air Quality Management District issued its first Spare the Air Alert of 2022 for Friday, urging people to reduce air pollution by working remotely, walking, biking or using public transit for work.
On Friday, cities east of Walnut Creek all are expected to rise to triple-digits, with the hottest spot expected to be 104 degrees in Brentwood. Livermore is forecast to reach 98 degrees, likely making it the hottest spot in Alameda County. In the Santa Clara Valley, Hollister and Morgan Hill are expected to reach 99, and San Jose 95.
An excessive heat warning that applies to inland areas such as the Sacramento Valley and northern San Joaquin Valley will go into effect at 11 a.m. today and remain in place until 11 p.m. Saturday. Authorities have not issued any specific fire-weather watches or warnings.
Temperatures were expected to remain warm overnight Thursday and today, with the lows in most of the region expected to stay in the upper 60s both nights. In the hills, the overnight lows might stay in the 70s, the weather service said.
Closer to the coast, the temperatures will be more mild because of the onshore flow from the ocean, the weather service said. The gauge is forecast to reach 88 in Oakland, 80 in San Francisco and 76 in Monterey.
The Spare the Air alert is the first since Oct. 3, when the region saw the last of 16 issued in 2021. There were 52 Spare the Air days in 2020.
Temperatures on Thursday were expected to peak about 7-10 degrees cooler than those that were anticipated for today.
The temperatures will drop an average of 7-10 degrees Saturday, and then as much as another 10 degrees Sunday, according to the weather service.
McCorkle said a chance exists that some rain could fall in the North Bay but that “it's a pretty low chance.”