Cloud cover clears, heat holds firm across Bay Area, Central Coast

The Bay Area and Central Coast are in the middle of a short-lived heat wave on Tuesday, with the hottest conditions as usual happening inland while coastal residents are seeing more moderate temperatures. 

The National Weather Service said in its daily forecast discussion that Tuesday's weather was being driven by a warm air mass aloft combined with clearing skies after several days of monsoonal cloud cover. Interior portions of the Bay Area, along with interior Monterey and San Benito counties, will have highs into the upper 90s, with some area exceeding 100 degrees, some 30 degrees warmer than coastal communities.

The Weather Service issued a heat advisory for the Sonoma coastal rage, North Bay and East Bay interior mountains and valleys, Santa Clara Valley and Eastern Hills, Salinas/Hollister Valley, Carmel Valley, and Monterey County interior. The advisory was in effect until 10 p.m. on Tuesday and warned of moderate heat risk with limited overnight cooling.

Although temperatures are similar to Monday's, Tuesday's heat was expected to feel more intense because of the disappearance of mid-level clouds and stronger direct sunshine, increasing radiant heating and pushing the heat risk higher, the NWS said. Forecasters said that several consecutive days of heat also mean buildings and pavement are retaining and radiating heat.

Onshore winds will increase by Tuesday afternoon and into Thursday, elevating fire weather concerns with the heat and decreasing humidity. The heat is expected to linger through Wednesday, with the peak of the heat event happening on Tuesday in inland locations. The NWS said cooler marine air will begin flowing back into the region beginning late Wednesday, bringing temperatures returning closer to seasonal averages and even cooler by Friday and Saturday, forecasters said.

High tides around the Bay Area and Monterey Bay area continued on Tuesday, with a coastal flood advisory still in effect until 4 a.m. Wednesday for the Monterey Bay area and until 4 a.m. Thursday for San Francisco Bay and San Pablo Bay. The combination of higher-than-normal astronomical tides along with thermal expansion and accumulated sea level rise will bring up to 1.8 feet above ground level near low-lying areas around shorelines and waterways, the NWS said.