A gradual, intense warm-up of temperatures throughout the inland portion of the Bay Area will culminate Tuesday with a quick boil that will leave triple digits lining parts of the region and mid-to-upper 90s in those places that don’t get there.
Then just as quickly, it will be turned off.
“It’s kind of the same story as last week, but it’s gonna be far more condensed,” National Weather Service meteorologist Dalton Behringer said Tuesday morning. “We’re gonna get really warm inland. But only for a day.”
That said, it will be a dangerous day, forecasters said. A heat advisory for the inland area was set to go into effect at 11 a.m. and last until 8 p.m. The area of the advisory runs from Cloverdale in the North Bay to Gilroy in the South Bay.
Residents were urged to ease up on afternoon or late evening exercise, encouraged to drink plenty of water, and to advised to stay in shady or cool places.
The hottest spot in the region is expected to be Brentwood in far east Contra Costa County, where the thermometer may reach 102 degrees, forecasters said. The weather service predicted that Concord in central Contra Costa County and Livermore in Alameda County each would reach 99 .
The South Bay is expected to be just slightly cooler, with Morgan Hill expected to pace Santa Clara County at 95. San Jose is forecast to hit 90.
Closer to the coast, the needle isn’t expected to get nearly so high. San Mateo is expected to peak at 82 degrees, Oakland at 79 and San Francisco at 72.
“The marine layer stayed intact,” Behringer said. “That’s what’s keeping it cooler near the coast. The people farther inland should start to feel it’s impact as it deepens a little more (Tuesday night).”
The quick heat-up is the result of a small high-pressure ridge that has not been able to gain footing because of persistent low pressure in the Gulf of Alaska that’s still present, Behringer said.
“It continues to rotate a few disturbances our way, and that’s what kept these heat-ups relatively short,” he said.
Overnight lows into Wednesday are expected to be back in the 50s for much of the region, and Behringer said that by the weekend, “we’ll be looking at normal temperatures for this time of year. Seventies and 80s.”