San Francisco sees first-ever tornado warning of winter storm

A tornado warning has been issued for the first time ever in San Francisco as thunderstorms swept through the region, toppling trees and causing major power outages.

The warning was issued just before 06:00 local time (14:00 GMT) Saturday for northern San Mateo County and parts of downtown San Francisco.

The storm caused power outages for more than 221,000 people in northern and central California, according to PowerOutage website.

The city last saw a tornado in 2005, though it hit without a clear radar signature, so no warning was issued in that case, National Weather Service (NWS) meteorologist Roger Glass told the AP news agency.

More than a million residents were awakened Saturday morning in San Francisco and its suburbs to alarms on their cellphones warning them to “shelter now.”

Winds of up to 60 mph (96 km/h) ripped through the area, the NWS said.

But a few minutes later, NWS Bay Area said the warning was over and the storm had moved out of the city center.

Authorities were assessing the damage to determine if a twister had occurred.

Nearby San Mateo County was last issued a tornado warning in 2011.

The NWS Bay Area warned that residents should still steer clear of the ocean this weekend, with a coastal flood advisory in place until Monday.

San Francisco’s tornado warning came just a week after the city saw its first ever tsunami warning

The brief advisory was issued for northern California and southern Oregon after a 7.0 magnitude earthquake struck off the state’s northern coast.

It was later lifted and no one was injured.