Bay Area Dances on the Edge of a Heat Wave, Fire Danger Looms

Homes in San Francisco’s sunnier neighborhoods, like the Mission District, aren’t known for having air conditioning, so with temperatures expected to peak up to 85 degrees over the next few days, forecasters said residents should open windows and let down their blinds — or escape the heat altogether by heading to Fort Funston to cool off.

“If it gets really hot inside, go find a local park where you can sit under a shade tree or head west to find that breeze at Ocean Beach,” said Brian Garcia, the National Weather Service’s Bay Area warning coordination meteorologist. “It’s going to be a lot cooler out there, and it’s going to keep you a lot safer.”

Across the city by the bay, Garcia said temperatures could sneak above average in neighborhoods along the bay shore and only slightly cool off at night. That’s why he said the weather service issued a heat advisory for Tuesday for the entire city, which he calls a “rare event.”

“It’s going to take some time for these places to cool off,” he said. “We’re crossing some thresholds in the city that put us outside the norm, with minimum temperatures only dropping into the low 60s.”

Through Friday, temperatures in inland cities like Healdsburg, Concord, Livermore and Morgan Hill could spike into the triple digits. A heat advisory will be in effect on Wednesday and Thursday for temperatures ranging 10 to 20 degrees above average for inland areas, according to the weather service’s daily forecast discussion for the Bay Area.

Farther inland in the Central Valley, the weather service has issued a moderate to major heat risk advisory with triple-digit temperatures from Redding to Sacramento.

“We expect about 10 to 15 degrees above the climatological normal in many of these cities,” said Katrina Hand, meteorologist with the weather service in Sacramento. “We expect high temperatures in the triple digits up to 107 degrees.”

The warming trend in the Bay Area doesn’t quite equate to a heat wave, but Garcia said such conditions — mainly a spike from average temperatures for several days — are “teetering right on the edge” of becoming a reality.

Garcia also expects nighttime lows, especially at high elevations around the region, to remain relatively warm. Combined with wind gusts of 20 to 30 mph and ample dry grass and brush, that makes for the perfect conditions for igniting wildfires.

“Fire danger is widespread across the Bay Area now,” he said. “Essentially, what we’re looking at right now is a tinderbox of dry fuels at elevation. If a spark occurs, it could expand quickly into flames and spread rapidly.”

Electricity grid operators also worry that several days of heat could increase the risk of power outages. In a heat bulletin issued late last week, the California Independent System Operator cautioned utility companies to defer maintenance scheduled between Wednesday and Friday to ensure enough generation. Meanwhile, the Bay Area Air Quality Management District has issued a Spare the Air Alert for smog for Tuesday and Wednesday.