Cool news hits part of Bay Area, as weekend heat wave begins to build
The foundation for the summer’s second heat wave — a searing blast that will take inland temperatures past 100 degrees and is bringing warnings from state officials — continued to be formed Wednesday, but the National Weather Service did have one bit of cool news for the Bay Area.
“Normally, when you see these heat waves with these strong high-pressure ridges, we get offshore winds that are warm and that just makes it miserable for everyone,” NWS meteorologist Sean Miller said Wednesday morning. “This time, we will still be getting the onshore winds that are cool. So some of the places near the beaches and water are not gonna get so hot.”
That likely will mean a few degrees of consolation for many Bay Area residents. Temperatures in many areas that were forecast to go past 100 degrees during the heat wave instead may top out in the high 90s, according to weather service’s latest forecasts.
“The core of (the heat wave) will be Friday and Saturday,” Miller said. “We’ll still feel it Sunday.”
Forecasters said Morgan Hill will be under 100 by Sunday, and that San Jose will likely not reach 90 degrees Saturday and top out at 92 degrees Sunday.
Oakland and San Mateo are not expected to rise above 79 at any point this weekend, and most areas of San Francisco will not rise above 69 degrees, according to the weather service.
The blast of heat will be another brief one, like the summer’s first heat wave as June turned to July. Miller said it will be over by Monday and that “through the next week after that or so, nothing is showing us getting quite as hot as this.”
Still, the far inland areas will continue to sear, especially in the Sacramento Valley where temperatures are expected to run from 106 to 112 degrees. State officials scheduled a 1 p.m. press conference Wednesday to discuss the heat wave and the weather service issued an excessive heat warning for the Sacramento Valley to run from 11 a.m. Saturday until 11 p.m. Sunday.
Bay Area safety officials urged residents to take precautions such as drinking plenty of water, limiting their outdoor time and holding off on mowing lawns or any other activity that could cause a spark leading to fire.
In the far east Contra Costa County city of Brentwood, the temperatures are forecast to reach 108 degrees on Saturday, three degrees higher than Friday. In Livermore, the hottest spot in Alameda County, the thermometer is expected to reach 102 on Saturday.
In Morgan Hill, often the hottest spot in the Santa Clara Valley, the temperature is likely to hit 100.
Miller said that in the case of Brentwood and Livermore, the thermometer will be influenced more from the Sacramento Valley than the marine layer. Thus, temperatures are expected to remain scorching hot in those areas through Sunday — Brentwood at 109 and Livermore at 103, according to forecasts — while much of the rest of the Bay Area region begins to cool off. The excessive heat warning also runs from Brentwood west to Hercules.
Concord, which was forecast to hit 103, now is likely to peak at 100 on Saturday. Walnut Creek, expected to hit 101, won’t reach the century mark, according to forecasts. In the Lamorinda area, temperatures are expected to be in the low 90s.
By Monday, temperatures mirroring those in June and earlier in the month are expected to return.
“We’re gonna have a trough come in and it’s gonna nudge that high pressure just a bit,” Miller said. “That will allow the onshore wind from the ocean to become even stronger, and it will cool off even more of the inland part of the region like it has been.”
The onshore winds also are expected to keep the air quality from getting overly dirty. The Bay Area Air Quality Management District said the air throughout the region is expected to be moderately healthy, meaning those with unusually sensitive breathing issues should limit their outdoor time.
This is a developing story. Please check back for updates.