The lingering energy of Tropical Storm Alberto caused hundreds of dry lightning strikes in California’s Central Valley on Monday — with almost no measurable rain — sparking several wildfires in the region.
Eastern Fresno County saw the highest concentration of lightning strikes, with more than 1,000 strikes in just three hours Monday, while at least five brush fires burned, according to the California Department of Forestry and Fire Protection.
“And we’re expecting more today,” National Weather Service meteorologist Emily Wilson of Hanford said Tuesday.
Dry lightning struck dry areas in the San Joaquin Valley and in the Sierra Nevada, he said, where it could spark additional wildfires in what has been a very active fire year for California, with total acreage burned so far. drastically exceeding the five-year average.
“(The crop) is growing very quickly because of the heat in June, so the grass dries out very quickly,” Wilson said. “We may get drier lightning strikes and that could lead to more grass fires.”
In 2020, a series of summer storms caused lightning strikes that led to the nation’s worst wildfire year in recorded history, with more than 4 million acres burned.
On Tuesday, there is a 10% to 30% chance of thunderstorms in the eastern San Joaquin Valley and especially along the Sierra Nevada peaks, according to the National Weather Service forecast discussion.
The weather service warned that the storm brought the possibility of dry lightning and erratic winds, with little rain, leading to dangerous fire conditions. There is also the possibility of thunderstorms along the Central Coast and throughout the Bay Area, where lightning is the greatest concern.
Watch out for lightning, especially dry lightning with thunderstorms producing less than a tenth of an inch of rain. Winds are strong and erratic with gusts up to 40 mph. #cawx pic.twitter.com/xrsdNJufA7
– NWS Hanford (@NWSHanford) June 25, 2024
Most of the region will continue to see triple-digit heat through at least Tuesday.
The storm that hit California this week is the remnants of Tropical Storm Alberto that moved northwest after hitting eastern Mexico last week, Wilson said.
“All the moisture has been quite wet, but there is still energy there,” he added. “Enough energy to generate all the lightning.”
The Bolt and Flash fires ignited Friday afternoon in eastern Fresno County, and grew to become part of a complex of wildfires burning nearby, according to Cal Fire. Several communities near Wonder Valley are in danger of evacuation due to the fire.
The largest, the Bolt fire, had grown to 1,742 acres as of Tuesday evening, more than double from Monday night, and is 10% contained, according to Cal Fire. The Flash fire grew to 982 hectares, and there is 15%. The Hog fire – the latest of the fires, burning Tuesday – reached 174 hectares, without containment.
“Some of the fires that are happening right now are from yesterday,” said Carlos Molina, a National Weather Service meteorologist in Hanford. He said the most recent Fresno County fire started because of a lightning strike on Friday — but it didn’t touch the dry fuel, but it took hours for it to rise.
“The fire started today as a remnant of a lightning strike that happened yesterday,” Molina said Tuesday afternoon. He said Fresno County didn’t see much additional lightning Tuesday.
The Muscat Fire, which started on Monday, reached more than 100 acres by Tuesday morning, but was 100% contained by evening, according to Cal Fire. Crews also responded to two other small fires in the area Monday, which were quickly put under control.
The cause of the wildfire is still under investigation, but the National Weather Service says lightning has fueled some of the fires since Monday.
Wilson urged residents to remain vigilant until at least Tuesday evening.
“Because it’s a dry thunderstorm, there’s a possibility of new fires and that’s a big concern for us right now,” Wilson said. “When you hear thunder, there is always lightning. … Go inside.”
