Here's where it's forecast to break 90 in the Bay Area on Tuesday
The heat is on across the San Francisco Bay Area.
With a high pressure system hunkered down over the West Coast, temperatures are expected to be even warmer on Tuesday than they were on Monday.
"Tuesday will be the hottest day out of the three days we expect the warmer temperatures," said National Weather Service Gerry Diaz, noting that the warm spell started Monday and will run into Wednesday. "Tuesday will be the day where we have the highest likelihood of a few places hitting 90 degrees, including locations above 1,500 feet in the North Bay, parts of the East Bay such as Livermore and Concord, and spots along the 101 corridor in the South Bay such as Gilroy."
On Monday a handful of locations hit the 90s, with Napa reaching a high of 92 degrees, Concord 91 and Santa Rosa and Livermore 90.
With clear, sunny skies overhead, interior areas will generally warm into the 80s with a few lower 90s in the hottest spots. Slightly cooler conditions will prevail at the coast with afternoon highs mostly in the 60s and 70s, although Santa Cruz could reach 80 degrees.
Wednesday will be slightly cooler and afternoon highs are forecast to range from 80 to 85 degrees in inland valleys and stay in the 60s in coastal areas.
The wind pattern is contributing to the warm spell with the cooling ocean breeze subsiding, while northerly offshore winds kick up.
The offshore winds blow hot air from inland areas toward the coast and are known for pushing up temperatures and drying out the landscape, essentially sucking the moisture out of the vegetation and leaving it tinder-dry and vulnerable to burning.
The offshore winds will be strongest to the east of the Bay Area in the Central Valley where a red flag warning is in effect through 5 p.m. Tuesday. The warning is only in effect in Solano County in the Bay Area.
"Some of the good news for the Bay Area is the strongest offshore winds will be over the Central Valley," said Diaz. "We only expect offshore winds in the Bay Area above 1,500 feet. Right now across the entire area, we have some of those winds over 2,000 feet, winds getting into the 30 to 40 mph mark."
The high pressure ridge is forecast to weaken Wednesday afternoon and the sea breeze will strengthen, bringing cooling to the region. The offshore winds are expected to ease. Inland highs will drop into the 70s on Thursday while coastal spots are expected to be in the low 60s.