Dangerous fire weather is expected across much of California on Friday, as temperatures across the state are expected to continue rising over the next few days marking August’s first heat wave.
With a threat of thunderstorms and dry lightning over much of Southern California, as well as parts of the Central Valley and the Bay Area, through Saturday, forecasters are warning the instability could create a dangerous combination for wildfires, both new starts and those still burning.
A red flag warning — an alert for critical fire weather — was issued for Friday across the mountains and deserts in Los Angeles, Ventura, Santa Barbara and Kern counties, as well as parts of the Sierra Nevada, with erratic winds possible along with dry lightning.
“Critically dry fuels will be receptive to any lightning-based ignitions, and dry/gusty thunderstorm outflow could contribute to wildfire spread,” the National Weather Service in Hanford warned. The red flag warning is in effect where the Borel fire in Kern County has grown to almost 60,000 acres, as of Friday morning. It is 47% contained.
“There will likely be at least a few new wildfire ignitions over the next 72 hours due to lightning in California, and these could occur in SoCal, NorCal, or both,” Daniel Swain, a UCLA climate scientist, wrote in a blog post Thursday.
The red flag warning is an ominous sign for what experts say could be an even more active fire month than the last, with the National Interagency Fire Center issuing an outlook that much of Northern and Central California have an above average chance to experience significant wildfire in August. A much larger swath of the state is included in that above-average category, compared with predictions for July — though California fire officials have already said that the beginning of the summer was particularly explosive. On Friday, the Park fire in Butte and Tehama counties became the state’s fourth largest fire in recorded history at more than 397,000 acres.
“In comparison to the outlook issued a month ago, larger areas of the West are expected to experience above normal significant fire potential in August and September,” the National Interagency Fire Center August outlook.
High temperatures will also continue to drive fire growth and impede firefighting. Weather officials are warning of another “prolonged heat wave,” particularly in interior Southern California, where temperatures could reach up to 110 by Monday.
“Temperatures will slowly warm each day, potentially leading to dangerous and significant heat risks across the interior by Sunday or Monday and continue through most of next week,” the National Weather Service office in Oxnard wrote in Friday’s forecast discussion. An excessive heat watch has been issued across interior southwest California beginning Sunday, warning of “dangerously hot conditions” and the potential for heat illness. The heat’s peak across the Southland is expected Monday through Wednesday.
Temperatures are also forecast to climb statewide; they aren’t yet forecast to be as extreme but still long-lasting, which officials continue to warn can cause health effects.
“Another heat wave is now underway, and it will likely be both prolonged … and double-peaked,” Swain said. “However, there is some good news in this: Right now, there’s no indication this heat wave will be anywhere near as intense or prolonged as the July event.”
Long-term climate predictions also show that California temperatures are only expected to be slightly above average in August, a prediction that is not as extreme as what was forecast for July.