Rain returned to the Bay Area on Thursday, starting with fairly significant downpours in the North Bay in the early morning that later moved into the East Bay.
Residents around the East Bay reported lightning and thunder in the morning along with minor amounts of rainfall. The National Weather Service issued a special statement because of those reports, which also included some hail.
Some residents in Concord were rattled by unexpected booms as a thunderstorm rolled through.
"It actually kind of shook the house a little bit," Stacie Bassi said. "That’s how powerful it was."
Lightning hit several power poles and is believed to have started a fire that destroyed an abandoned building.
"It’s undetermined what the cause of the fire was," George Laing with the Contra Costa County Fire Protection District said. "It is reported by witnesses that lightning had struck in the area around the time of the fire. That may be an attributable cause."
The weather service's alert warned people of wind, hail and possible cloud-to-ground lightning, and it urged people to seek shelter.
"There is a tremendous amount of electrical energy in a lightning strike," Laing said. "Very dangerous."
Scattered showers are expected to continue Friday and Saturday, according to the weather service.
Wind gusts could reach 50 miles per hour Friday along the coast north and south of San Francisco Bay, according to a wind advisory issued early Thursday morning by the National Weather Service.
The advisory is for 7 a.m. to 7 p.m. Friday for a long stretch of coastline, from about Sea Ranch in northern Sonoma County south to about Davenport just north of Santa Cruz.
Northerly winds are expected from 25 to 35 mph with gusts of 40 to 50 mph.
Winds are expected to be strongest in San Francisco and Half Moon Bay and to ease slightly as they move inland.
For real-time weather conditions, alerts and a detailed forecast, go to the NBC Bay Area weather page.
Bay City News contributed to this report.