Lightning and thunderstorms hit across the Bay Area on Monday afternoon and into the evening, giving residents a late-summer weather spectacle rarely seen in the region.
Forecasters observed at least 1,000 lightning strikes in the Bay Area, with isolated thunderstorms soaking parts of the region amid 90-degree heat.
NBC Bay Area Chief Meteorologist Jeff Ranieri said areas in the East Bay, South Bay and the Santa Cruz Mountains saw a good amount of rain as well as lightning and some hail.
Gusty winds also were reported, especially in coastal areas, where a small-craft advisory was in effect.
Isolated thunderstorms started in the afternoon then a second phase developed in the Central Valley and headed toward the Bay Area Monday evening, forecasters said.
The weather service warned of 30 mph wind gusts and dime-size hail expected in parts of Alameda and Santa Clara counties. Officials said frequent cloud-to-ground lightning was occurring and advised people to seek shelter inside.
More than 8,700 customers across the region were without power late Monday, according to PG&E. More than half the outages, about 4,400, were in the East Bay, and nearly 3,000 more were on the Peninsula, PG&E said. There were also 609 in the South Bay, 554 in San Francisco and 200 in the North Bay without power.
The lightning also caused at least 16 flights destined for San Francisco to be diverted to Mineta San Jose International Airport, according to an airport spokesperson.
One passenger said his plane sat on the San Jose tarmac for about 30 minutes before heading back north to SFO.