As summer fades, Bay Area gets a lightning show

"By 5:30 a.m. Tuesday, the weather service had recorded about 4,800 lightning strikes from Sacramento to San Luis Obispo, including 1,300 that touched the ground. The weather service said an unknown amount of fires started overnight in southeast Monterey County and in southwestern Fresno County early Tuesday. It was not known immediately how big any of those fires were, but Cal Fire had not reported any new ones on its list of California's major ones."

"The lightning came with low rumblings of thunder and in some areas small bits of rain that were too small to measure, Gass said. It developed quickly as monsoonal moisture from the southern part of the Pacific Ocean and the southwestern desert shifted course and moved north, he said. "There already was a trough of low pressure in the upper part of the atmosphere," Gass said. "Then you had the monsoonal moisture that worked its way into our area.""

Thousands of lightning strikes lit the sky from the Bay Area to the Central Valley overnight as summer unofficially ended. The strikes came from unstable air and monsoonal moisture moving north from the southern Pacific and southwestern desert. About 4,800 strikes were recorded by 5:30 a.m., including roughly 1,300 ground strikes. The strikes sparked unknown fires in southeast Monterey and southwestern Fresno counties, though Cal Fire reported none as major by 8 a.m. The Garnet Fire in Fresno, at 26,982 acres and 12% contained, raised concern that lightning could create more fires within that blaze. Forecasts said lightning was tapering but isolated thunderstorms remained possible in the East Bay.

Read at The Mercury News