Cooler temperatures replace heat wave

Highs were about 10 degrees lower on Friday for most Bay Area cities

Finally, some relief from scorching temperatures arrived for much of the Bay Area.

The heat wave that blanketed much of the Bay Area all week began easing Friday, with high temperatures about 10 degrees cooler, according to the National Weather Service.

San Jose only reached a high of 83 degrees Friday, 13 degrees below Thursday’s high of 96, according to the weather service. Concord reached a high of 91 degrees, Los Gatos 87, Oakland 72 and San Francisco posted 73.

A heat advisory was in effect through 9 p.m. Friday for some Bay Area locations, including Livermore, where temperatures reached 94 degrees. That was 12 degrees cooler than Thursday’s high of 106.

Further cooling is expected through the weekend as temperatures return to normal by Monday — in the 80s inland and cooler at the coast.

“The cooling trend is going to bottom out early next week,” said Drew Peterson, a meteorologist with the weather service.

Thursday’s scorching temperatures fell short of setting any heat records in the Bay Area, but there were still some sizzling locations, with Livermore and Concord posting the highest readings and 105 degrees.

The heat wave remains in effect for much of the Central Valley, where many cities were expected to see another round of triple-digit temperatures Friday.

Thursday’s heat sent electricity demand soaring as people cranked up air conditioning to stay cool. PG&E spokeswoman Mayra Tostado said the utility expected to set a new record for energy use Thursday evening. It anticipated consumers in its service area would use at 106 22,700 megawatts of electricity, eclipsing an earlier peak of 22,468 megawatts set in 2006.

The utility had enough energy to meet the high demand, she said. The company reported scattered, small outages through the day, particularly in the North Bay. Many of the outages were attributed to overheated and blown out transformers.

The scorching weather — blamed for the deaths of two elderly people this week in San Jose — was caused by a dome of highpressure air known as the “Four Corners High.” A mountain of dense air at least six miles high and extending from the TexasNew Mexico border to the California-Oregon border and down to Baja, Mexico, blocks cool ocean air from moving inland.

“It puts a warm lid over the West Coast. It shuts off our sea breeze, and we start heating up,” said Jan Null, a meteorologist with Golden Gate Weather Services in Saratoga.