Lightning strikes: Red flag warning in place for North, East Bay

The National Weather Service issued a red flag warning Thursday for the North Bay and East Bay mountains, hills, and valleys because of a slight chance of thunderstorms that could bring wildfire-sparking lightning.

The weather service said the main concern is lightning strikes in extremely dry vegetation. The thunderstorms arrived over Napa and Sonoma counties before they could move into the East Bay overnight and into the early morning hours.

By 11 p.m. Cal Fire officials reported their Sonoma-Lake-Napa unit was at the scene of a 30 by 30 foot vegetation fire in the 1100 block of Wall Road near Dry Creek in Napa. Two engines will remain at the scene, while others will clear from the area. Officials did not say if this incident was weather related or what the cause of the fire was.

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There has been some precipitation associated with the thunderstorm, but it would not be enough to extinguish any fires started by lightning due to the extremely dry vegetation in the region, weather service officials said.

Light precipitation moved into the North Bay by early Thursday evening. Petaluma, and Santa Rosa in Sonoma County both had reports of rain. Later in the evening, Santa Rosa Fire Department said they were seeing cloud to ground lightning strikes in their area. National Weather Service confirmed those cloud to ground lightning strikes in areas south of Cotati. 

Pacific Gas and Electric's power outage map showed more than 5,000 customers were without power shortly after 10 p.m. Within an hour those numbers had slightly dwindled. The updated map showed 500 to 4,999 customers still without power after 11 p.m. It was not clear if the outages were weather related. 

The weather service emphasized that the system "is not currently anticipated to be a repeat of the August 2020 dry lightning event" that caused devastating wildfires throughout the Bay Area.

The red flag warning is set to last from 5 p.m. Thursday through 11 a.m. Friday.

Bay City News contributed to this report.