The lingering energy of Tropical Storm Alberto triggered hundreds of dry lightning strikes in California’s Central Valley on Monday, with little measurable rainfall and igniting several wildfires in the region.
The highest concentration of lightning was in eastern Fresno County on Monday, with more than 1,000 lightning strikes in just three hours, igniting at least five brush fires, according to the California Department of Forestry and Fire Protection.
“We’re expecting more of these today,” National Weather Service meteorologist Emily Wilson said Tuesday in Hanford.
Dry lightning is striking dry terrain in the San Joaquin Valley and Sierra Nevada, she said, threatening to spark more wildfires in what is already a very active fire year in California, with the total area burned so far this year far exceeding Five-year average.
“[Plants] Because it was so hot in June, it cured very quickly, so our grass dried out very quickly,” Wilson said. “We may get more dry lightning strikes, which could spark more grass fires.”
In 2020, a series of summer thunderstorms triggered a lightning siege that led to the state’s worst year ever for wildfires, which burned more than 4 million acres.
There is a 10 to 30 percent chance of thunderstorms Tuesday in the eastern San Joaquin Valley, particularly along the Sierra Nevada ridges, according to the National Weather Service’s forecast discussion.
The weather service warned these storms could bring dry lightning and erratic winds with little rainfall, creating dangerous fire conditions. Thunderstorms are also possible along the Central Coast and across the Bay Area, with lightning being the biggest concern.
Beware of lightning strikes, especially dry lightning and thunderstorms that produce less than a tenth of an inch of rainfall. Winds were erratic, with gusts as high as 40 mph. #cawx pic.twitter.com/xrsdNJufA7
— NWS Hanford (@NWSHanford) June 25, 2024
High temperatures in the triple digits will continue to hit much of these areas through at least Tuesday.
The storm arriving in California this week is the remnant of Tropical Storm Alberto, which moved northwest after hitting eastern Mexico last week, Wilson said.
“Almost all the moisture has been washed away by the rain, but there’s still energy there,” she added. “Enough energy to generate all the lightning.”
The Bolt and Flash fires, which ignited in eastern Fresno County on Monday afternoon, had each grown to about 800 acres as of Tuesday morning without any confirmed containment, according to Cal Fire. Some communities near Miracle Valley are under evacuation warnings due to nearby fires.
Slightly south of the two blazes, the Muscat Fire started on Monday and had grown to more than 100 acres by Tuesday morning without any containment, according to Cal Fire. Crews also responded to two other small fires in the area on Monday, but they were quickly brought under control.
The cause of these wildfires is still under investigation, but the National Weather Service said a series of lightning started several of the fires on Monday.
Wilson urged residents to remain on high alert through at least Tuesday night.
“Because these are dry thunderstorms, they can spark new fires, which is a big concern for us right now,” Wilson said. “If you hear thunder, it could be lightning… get inside.”
