Southland heat wave will bring unstable conditions, intense fire danger

As crews continue to combat wildfires in Northern California, the southern part of the state is preparing for extreme heat and elevated fire danger.

The National Weather Service on Wednesday issued an excessive heat warning across portions of Southern California’s high desert, with the Apple and Lucerne valleys preparing for temperatures that could climb as high as 120 degrees by the weekend — potentially the hottest of the year so far.

An excessive heat watch will also begin Friday in the Antelope Valley, Cuyama Valley and interior San Luis Obispo County, where triple-digit heat could meet relative humidity levels as low as 10%.

The combination will create the increased potential for brush fires, officials said.

“Vegetation is very dry on the hillsides because we’ve had two very dry years in a row,” said meteorologist David Sweet with the National Weather Service in Oxnard, “and we’re also looking at 111 degrees. Any time you have hot temperatures, that’s also a contributing factor.”

The hot weather and fire activity are ratcheting up concerns and warnings from officials, who tweeted about the record-breaking heat.

Desert climate zones in Palm Springs, Thermal and Anza-Borrego all experienced their hottest June on record, the National Weather Service said — “and it wasn’t a close call.”

Palm Springs saw a mean June temperature 5.3 degrees above normal.

“When we get into the hottest period of the year in the summer, really high temperatures can definitely drive up the fire danger,” said Bruno Rodriguez, a meteorologist with the National Weather Service in San Diego. “What they can do is basically make the atmosphere more unstable.”

A slight moisture surge in the lower desert areas of the Coachella Valley on Thursday could keep temperatures there in check, he noted, but might make it feel more muggy.

In response to the extreme conditions, the United Methodist Church of Palm Springs opened a 24-hour cooling center. It will be open through Sept. 30 in partnership with homeless services provider Martha’s Village & Kitchen, the Desert Sun reported.

Meanwhile, evacuation orders have been issued in Plumas County, where gusty winds pushed the lightning-sparked Sugar fire over containment lines and set progress back significantly.

The fire had been at 70% containment Tuesday, but that plummeted to 28% Wednesday morning, officials said. The fire was reported at just over 3,000 acres by nightfall.

Sugar fire incident spokeswoman Pandora Valle said crews had to contend with another day of high winds and unusually hot temperatures Wednesday.

“The fire was very active today [with] winds coming from the southwest,” she said.

The Plumas County Sheriff’s Office issued mandatory evacuation orders for residents from Beckwourth Genesee Road to Harrison Ranch Road, as well as for the area around Frenchman Lake. Residents on Dixie Valley road are under an evacuation advisory.

The Sugar fire is part of the larger Beckwourth Complex, which also includes the Dotta fire. As of Wednesday evening, that fire had reached 670 acres and 48% containment.

But crews have turned a corner on several fires burning near the Oregon border — including the Lava, Salt and Tennant fires, which together have seared nearly 50,000 acres.

The Tennant fire remains at 10,614 acres, according to spokesman Irvin Barragan, but favorable weather conditions enabled firefighters to increase containment from 57% Tuesday to 71% Wednesday morning.

The Salt fire ignited June 30 and went on to destroy more than two dozen homes. It held steady at 12,546 acres and 25% containment Wednesday morning, officials said. Some evacuation orders were lifted Wednesday.

The lightning-sparked Lava fire, which ignited June 2, has burned 25,001 acres and is at 72% containment, spokeswoman Clare Long said. All evacuation warnings and orders were lifted Wednesday.

Crews are now focused on mopping up hot spots, she said, and are sharing resources to combat the Salt fire.

Times staff writer Leila Miller contributed to this report.