Post fire becomes California’s largest wildfire of the year

A major wildfire in northern Los Angeles County continued burning Monday evening southeast toward Pyramid Lake, scorching more than 15,000 acres to become the state’s largest blaze of the year.

The Post fire was 15,611 acres as of 7:34 p.m. Monday and 20% contained. It was burning in steep, hard-to-reach areas and threatening homes as well as infrastructure, including power lines, dams and oil pipelines, officials said in a status update on the California Department of Forestry and Fire Protection’s website.

Officials cautioned Monday evening that heavy smoke from the Post fire might make it difficult for drivers to see on the 5 Freeway south of Gorman and north of Santa Clarita. Residents in communities including Castaic, Piru and Santa Clarita will likely notice the smoke as well.

Firefighters will focus much of their attention on building and reinforcing fire lines around the perimeter while helicopters and air tankers try to slow down the fire’s advance and douse hot spots as conditions allow, officials said in their update.

L.A. County officials said high temperatures and low humidity were expected Tuesday, a bad combination for firefighters attempting to snuff out flames as the fire chews through vegetation dried out by the heat and lack of moisture in the air. Wind gusts may reach up to 55 mph, further complicating firefighting efforts.

If northeast winds intensify, the Post fire might be pushed deeper into the forest and wilderness areas. This could cause the fire to spot up to three-quarters of a mile away — meaning small pieces of burning leaves and grass could travel that distance and start small fires farther away from the fire line, fire officials said.

“Conditions have continued to support the rapid spread of the wildfire,” said Ariel Cohen, a National Weather Service meteorologist in Oxnard.

Red flag warnings, which are alerts for dangerous fire conditions, were in effect for the area through at least Tuesday evening as the air was expected to dry out during the day and temperatures were expected to rise.

Such severe warnings have also been issued across large swaths of inland California, with the alerts forecasting winds that carry “the potential for rapid fire spread,” from the northern Sacramento Valley through the Antelope Valley.

Since Saturday, more than 20 fires sparked across California, burning over 20,000 acres, the majority of which were still not fully contained Monday, according to the Cal Fire website. Several triggered evacuations and damaged buildings, including the Post fire.

There had been predictions for a subdued start for the state’s wildfire season this year, given a series of late-season, moisture-heavy storms, but this new spate of fires heightened concerns.

“It’s pretty early and this is [a] pretty large fire,” Los Angeles County Fire Department spokesperson Craig Little said of the Post fire. “We can always hope, but I’m thinking there’s going to be more of this in the future for the summer. ... It’s very early for a fire of this magnitude.”

Such early-season fires are fueled by heat-dried grasses, and Southern California’s hillsides and mountains are dense with vegetation after two back-to-back wet winters. Because of that, more dangerous fires that engulf larger trees and plants are likely in store for later this year, according to Daniel Swain, a climate scientist with UCLA.

“We could, in fact, see a very active finish to fire season 2024, but we aren’t there yet, despite the current activity level,” Swain said during a briefing Monday. “This is not yet indicative of really active conditions.”

In particular, the forested, high-elevation areas that have endured some of the state’s worst wildfires in recent memory are still moist following two strong wet seasons and haven’t yet started to display much wildfire activity.

That could change as conditions get hotter and drier for longer stretches of time, Swain said. Those areas will likely start drying out in July at lower elevations and August at higher elevations, with fire activity possibly lasting longer than usual due to two years of vegetation build-up.

“Expect September — and maybe even October and parts of November in some areas — to feature very active fire conditions this season,” Swain said, adding that blazes that ignite later in the season could become increasingly intense.

The fires that ignited over the past weekend are likely a foreshadowing of what’s to come.

The Post fire on Saturday forced about 1,200 people to evacuate from the Hungry Valley Park and Pyramid Lake areas, not far from the 5 Freeway, according to firefighters.

On Monday, officials also ordered areas south of Pyramid Lake to be evacuated, including the Oak Flats Campground. An evacuation warning was also issued for Paradise Ranch Estates.

The fire has destroyed an auto shop and threatened dozens of other buildings. One person has been injured, Little said.

The mountainous terrain has forced the firefighting effort to rely more heavily on air crews — 24 helicopters and multiple air tankers, as of Monday evening — but high winds have made water drops less effective, Little said.

Almost 1,700 firefighters and other personnel continued to battle the flames Monday. The Ventura County Fire Department and U.S. Forest Service were aiding in the effort. The Post fire’s cause remains under investigation.

Also in Southern California, about 1,100 acres had been burned by the Hesperia fire in San Bernardino County, prompting road closures and an evacuation warning. The fire was 72% contained as of Monday evening, according to Cal Fire and the San Bernardino County Fire Department.

The Tuscany fire ignited Monday and burned 350 acres in Palm Springs, according to local officials. As of Monday evening, it was 50% contained, according to Cal Fire.

Multiple fires also burned across Northern California.

In Sonoma County, the Point fire burned more than 1,200 acres and several structures south of Lake Sonoma. It was 20% contained Monday evening, according to Cal Fire, after starting Sunday afternoon.

The Sites fire, burning northwest of Sacramento in Colusa County, started Monday afternoon and erupted to almost 4,500 acres by the evening. Firefighters had been unable to contain it, hampered by hot dry conditions, officials said.

And southeast of Sacramento, the Aero fire started Monday afternoon in Calaveras County and had already burned more than 5,000 acres by about 10 p.m. and had no containment, according to Cal Fire.

As Swain took stock of the current fires, he noted that the rest of the season could be affected by a number of other factors, including the current transition from the El Niño weather pattern to La Niña.

La Niña is associated with drier conditions along the West Coast and in Southern California in particular. La Niña was last in place during the state’s three driest years on record, 2020 through 2022, which also saw the state’s biggest wildfire seasons on record.

Climate change is also driving warmer global temperatures and a thirstier atmosphere, both of which can extract more water from the landscape and pave the way for hotter and faster fires in the West and other arid areas, Swain said.

What’s more, the upcoming Fourth of July holiday is often linked to wildfire ignitions, and there is potential for that pattern to repeat this year, he added.

“The good news is increasingly in the rearview mirror,” Swain said. “As these conditions continue to rapidly warm up, dry out and get windier, the bad news is that I think that the back half of this season is going to be much more active — with a lot more concerning level of wildfire activity in a lot of areas — than the first half.”