A first-ever tornado warning was issued for San Francisco County early Saturday

A tornado that touched down Saturday afternoon in the city of Scotts Valley in Santa Cruz County injured three people and caused significant damage in the area, according to the National Weather Service.

It occurred around 1:40 p.m. and lasted about five minutes, based on radar, videos and firsthand accounts, said Matt Mehle, a meteorologist with the National Weather Service Bay Area.

The wind speed peaked at 90 mph and the tornado’s path covered nearly a third of a mile at 30 yards wide along Mount Hermon Road in Scotts Valley, according to the weather agency.

A storm survey team with the National Weather Service observed a wide range of damage to the area, including downed trees and power poles, trees stripped of branches, overturned vehicles and damaged street signs.

Three people injured in the tornado were transported to a hospital, according to a report by the San Francisco Chronicle. Scotts Valley police said two of them were released Saturday evening, but the other remained hospitalized, though was expected to survive, the police said. That person sustained broken ribs and a punctured lung after their vehicle was flipped over by the tornado, police told the Chronicle.

A social media post by the Scotts Valley Police Department said that the tornado touched down near a Target store on Mount Hermon Road and that multiple power lines were down.

“The road is totally blocked in all directions in the city,” the police statement said. “Please stay out of the area.”

Police said Mount Hermon Road between Lockewood Lane and Scotts Valley Drive is closed to allow repairs of damaged PG&E equipment and to allow crews to clean debris and hazards out of the roadway.

It’s not the first tornado recorded in Santa Cruz County — seven have occurred before, Mehle said. California sees about 10 or 11 tornadoes each year, he said.

In San Francisco County, a first-ever tornado warning was issued early Saturday as thunderstorms and wind gusts of up to 80 mph swept through the region and caused widespread damage, officials said.

The National Weather Service said its crews found numerous large trees in the county that were uprooted or snapped at the base by straight-line winds. In addition, at least one structure suffered roof damage and there were several downed power lines, according to a statement from the weather agency.

More than 1 million people in the county were under the warning, which went out at 5:51 a.m. and was lifted by 6:15 a.m., said Lamont Bain, a meteorologist with the National Weather Service Bay Area.

The advisory was the first time the agency had ever issued a tornado warning for San Francisco County, he said. San Mateo County was last issued a tornado warning on March 18, 2011.

“It’s certainly unusual. We don’t see the ingredients come together all the time for tornadoes,” Bain said.

In addition to moisture, “you need the combination of lift, you need some instability and you need some wind shear. We saw all of those things come together for a brief period of time this morning,” he said.

Bain said the tornado alert was “a good reminder for people to always have multiple means” to receive weather and warning information. That includes signing up for text alerts, checking news reports and tuning in to weather radio.

Rain showers were forecast for the rest of the day in San Francisco, with wind gusts peaking at 30 to 35 mph. The rain was expected to end Saturday night, with dry conditions on Sunday before another dose of rain Monday.

Power outages were widespread as a result of the storm, which began Friday. PG&E said wind gusts of 95 mph were recorded in Humboldt County on Friday evening. San Francisco International Airport experienced 83-mph winds early Saturday.

PG&E said that its crews were working to repair the damage and that power had been restored to more than 95,000 customers by 10:45 a.m. Saturday.