Triple-Digit Temperatures, Heat Advisory Forecast For Tri-Valley

SAN RAMON, CA — A heat advisory will take effect for the East Bay beginning Sunday morning, with triple-digit temperatures forecast in the Tri-Valley. The widespread warming trend will start to envelop the Bay Area Saturday, with hot temperatures increasing fire risks. According to the National Weather Service, the North Bay, interior East Bay, South Bay and Santa Cruz Mountains will likely see the hottest days on Sunday and Monday, with temperatures rising above 100 across the Tri-Valley.

An offshore flow will kick off Friday night and continue throughout the day Saturday, resulting in lowered humidity, and rapid temperature changes will likely initiate hot, dry, gusty winds that could increase fire risks, weather service officials said.

A red flag warning for Friday night through Sunday afternoon has been issued for the North Bay hills over 1,000 feet. Winds on Friday night across the North Bay hills are expected to produce gusts of 40 to 50 mph over the highest peaks and temperatures on Saturday are forecast to be in the 90s. The first red flag warning of the fire season prompted Pacific Gas and Electric to announce it might proactively turn off power in several Northern California counties within the next 18 to 36 hours to reduce the risk of wildfires.

The possible shutoff includes the North Bay and Sierra foothills, PG&E said. The potential power shutoff that would affect several thousands of customers in the North Bay includes portions of Napa and Lake Berryessa, portions of Suisun City, Vacaville and Winters and portions of Davis and Winters in Yolo County starting at 6 a.m. Saturday. The peak fire risk will last until 10 a.m. Sunday, according to PG&E. PG&E said its goal is to send customer alerts through automated calls, texts and emails before shutting off power.

The forecast calls for a slight cooling trend beginning Tuesday, with temperatures hovering in the high 80s across the Tri-Valley.

—Bay City News contributed to this report.