San Francisco was hit with its first-ever tornado warning after a devastating storm tore through northern California, flipping cars and leaving multiple people injured.
Around one million people woke up to an alert urging them to ‘take shelter’ early Saturday, after the warning was extended into parts of neighboring San Mateo County.
Forecasters have since confirmed that a tornado ripped through Scotts Valley, located an hour and a half south of San Francisco.
Several people were treated for minor injuries after cars were flipped over on Mount Hermon Road, KION reports.
Terrifying video showed motorists struggling to maintain control of their cars amid the heavy winds and trees downed in the middle of the road.
Another clip taken in Scotts Valley showed the powerful funnel of wind whipping up branches and detritus as it rampaged through a Target parking lot.
Gusts of up to 80mph also toppled power lines and plunged around 221,000 people into blackouts, with tens of thousands still to regain power.
The stormy conditions are the result of a powerful atmospheric river which battered the West Coast.
In San Francisco, roofs were left damaged and trees were uprooted amid gale force winds.
The area has not seen a tornado since 2005, according to the Weather Service which is now investigating if one actually occurred.
‘This was the first ever warning for a possible tornado in San Francisco. I would guess there wasn´t a clear signature on radar for a warning in 2005,’ said Roger Gass, a meteorologist in the Weather Service’s Monterey, California.
The fast-moving storm prompted warnings for residents to take shelter, but few people have basements in the area.
‘The biggest thing that we tell people in the city is to put as many walls between you and the outside as possible,’ Meteorologist Dalton Behringer said.
The tornado warning was issued at 5.51am and also included an alert for possible pea-sized hail.
The warning expired at around 6.15am, however winds of 83mph were recorded at San Francisco International Airport at 2.09pm.
California records an average of 11 tornadoes per year, according to the National Weather Service.
San Francisco residents are still being urged to avoid coastal areas until Monday morning due to an increased flood risk.
It comes just days after the City by the Bay was issued its first ever tsunami warning.
A monster earthquake off the coast of Northern California triggered the alert.
At least 5.3 million people in California were under a tsunami warning after the earthquake struck, the U.S. Geological Survey said.
It was felt as far south as San Francisco, where residents felt a rolling motion for several seconds. It was followed by smaller aftershocks.
There were no immediate reports of major damage or injury.