SANTA ROSA (CBS SF) – A small tornado destroyed a wood and corrugated metal shed at a business in Santa Rosa Friday morning, just hours before the powerful storm prompted a Tornado Warning for San Mateo County and knocked out power to many local PG&E customers.
The National Weather service said Friday that an Enhanced Fujita 1 tornado hit the area shortly before 10 a.m. An EF1 is characterized by a three-second burst of wind between 86 and 110 mph., which is roughly what witnesses describe hitting the Sequoia Landscaping Materials facility.
Sequoia owner Sue Minnigerode said she looked outside her business at 1330 King St. when she heard the wind howling around 9:45 a.m. and saw pieces of their 100-foot long shed fly onto nearby Pacific Avenue.
Debris was located as far away as 200 yards in some directions and a piece of corrugated roofing material was found 20 feet up a nearby tree.
A one-block area of Pacific Avenue between King and Wright streets was closed due to the damage, Minnigerode said.
California averages about six tornadoes a year, although most of those touch down near the Los Angeles Basin or in the Central Valley, according to a National Weather Service meteorologist.
“It’s not completely rare,” meteorologist Chris Stumpf said. “They do occur occasionally.”
Stumpf said the last time a tornado touched down in the Bay Area was March 21, 2005, when it struck South San Francisco. That vortex had wind speeds between 73 and 112 mph, which were strong enough to lift roofs and awnings off houses and down power lines.
Another funnel cloud was spotted above Ocean Beach as the same system passed over San Francisco.
In the YouTube video, the waterspout can be seen edging closer to
the shoreline before losing its momentum and dying out before posing a hazard to coastal homes.
At 11 a.m., a warning was issued for most of San Mateo County as the National Weather Service’s radar system picked up signs of a severe thunderstorms and possible tornadoes approaching the coast, meteorologist Steve Anderson said.
Winds of 30 to 40 mph, a downpour of rain, and pea-sized hail were reported, but not a tornado, Anderson said.
More than 2,000 PG&E customers in the Bay Area were without power at one point Friday afternoon due to separate outages in San Francisco’s Park Merced, Northern San Rafael and Orinda, a utility spokeswoman said.
Pea-sized hail was reported in Concord, Berkeley and Albany Friday night.
“There were reports of quite a bit of hail in Berkeley, about three inches,” Stumpf said.
One Berkeley resident reported a light dusting of snow Friday night in the Berkeley hills near upper Shasta Road.
More rain and thunderstorms are expected to inundate the Bay Area on Sunday, and Stumpf said that additional hail could be likely during those storms, which are expected to pack strong winds and more cold, unstable air.
“I wouldn’t be too surprised if there were some reports of hail on Sunday,” he said.
(Copyright 2011 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services may have contributed to this report.)