Storm cells batter Bay Area with lightning strikes, hailstorms and intense downpours

SAN FRANCISCO -- Cold, unstable air flowing in the wake of the latest atmospheric river Tuesday spawned lightning strikes, pounding hailstorms and intense downpours across the Bay Area.

The wintry maelstrom rolled into the region mid-morning and immediately began creating havoc. San Francisco firefighters rescued two people who were trapped in their vehicle after a tree toppled on it at Fulton and 19th Ave. in the Richmond District.

A tree also toppled onto a San Francisco Muni bus near Stockton and Sutter streets and pulled down an overhead wire.

Dozens also took to social media to post images and videos and to comment about the intensity of the storm.

The National Weather Service issued special weather statements warning of the intensity of the storm cells for San Francisco, Oakland, Concord, and the central San Francisco Bay.

A flash flood warning was also issued for San Francisco.

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"This is a dangerous and life-threatening situation," San Francisco officials said. "Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order."   

The weather service warned of the dangerous conditions.  

"Strong thunderstorms will impact portions of southeastern Marin, northern Alameda, Contra Costa, southeastern Sonoma, San Francisco and southeastern Napa Counties through 2 p.m.," weather service forecasters said. "At 12:58 p.m. doppler radar was tracking strong thunderstorms along a line extending from near Napa to near San Leandro. Movement was east at 35 mph."

"A colder unstable airmass will accompany the trailing upper level trough," weather service forecasters explained. " Showers and thunderstorms will be possible throughout the day Tuesday. Same hazards apply for any developed cells: small hail, gusty winds, heavy rain, and lightning. Snow levels do drop too, allowing for a mix of snow above 4,000 feet. Not expect much in the way of accumulation."

A cell that moved over San Francisco and the East Bay around noon triggered 5-10 lightning strikes every 5 minutes.  

The dramatics came on the 16th day of stormy weather that had led to floods, landslides, evacuations and at least 14 deaths statewide.

The two-week deluge has dumped 12.27 inches of rain in San Francisco -- the wettest 15-day period stretch going back to December 1866.