Threat Of Weekend Thundershowers Raise San Francisco Bay Area Wildfire Concerns

SAN FRANCISCO (CBS SF) -- Sweltering temperatures that have baked the San Francisco Bay Area will begin falling late Wednesday, but a new weather concern was lurking on the horizon -- a weekend storm front with the potential for thundershowers.

A dry late winter season has left much of the San Francisco Bay Area mired in severe drought conditions. The record heat over the last several days have further drained moisture from the tinder-dry hills, setting up prime wildfire conditions.

While there have been showers in the Bay Area in April and May, they fell far short of making up for the deficit rolled up by the first February without rain since 1864.

Calfire was already reporting increased wildfire this year. From January 1, 2020 through May 24, 2020, state officials said there had been 1,506 fires that have burned 1,967 acres. In comparson from January 1, 2019 through May 24, 2019, there were 884 fires with 1,677 acres.

The National Weather Service said a heat advisory would remain in place over the Bay Area until at least 7 p.m. Wednesday. Then the high pressure system that has been parked over the Pacific will be moving eastward.

The move opens the door to a low pressure system that has been moving slowly toward the region from north of the Hawaiian Islands. The system will be packing rainshowers and lightning storms.

"For what it's worth, latest lightning detection networks are already picking up some lightning near the upper low," weather service forecasters said. "Thunderstorm chances look more likely on Saturday as the colder core upper low moves through. Best chance for thunderstorms will be over the North and East Bay Saturday and early Saturday night."

When it comes to rainshowers, forecasters said the North Bay could received 1/4 to 1/2 inches by the time the showers move through.