Los Angeles Will Remain at High Risk of Fire Into Next Week

Firefighters from the L.A. County Fire Department stand ready as they battle a large blaze in the Palisades at night.

LOS ANGELES, CA - (NB360) Destructive wildfires continued to rage across the Los Angeles metro area on Friday, leading to extended mandatory evacuations and school closures throughout the region. The forecast for next week offers little hope of relief; conditions will remain conducive to both the expansion of current wildfires and the ignition of new ones, as strong winds persist amid unusually dry weather.

Authorities reported five major fires in the Los Angeles area as of Friday morning. The Palisades Fire in Pacific Palisades and Malibu has burned over 20,000 acres, while the Eaton Fire in Altadena has expanded to more than 10,000 acres. It is estimated that at least 10,000 structures have been destroyed across Los Angeles, with 10 fatalities reported.

Favorable conditions for fires include dry vegetation, low humidity, and strong winds. This combination makes it easy for fires to ignite and spread quickly; it was this dangerous mix that allowed the Palisades Fire and Eaton Fire to grow beyond any crew’s ability to control them earlier in the week.

Fire crews have since managed to begin controlling the fires, aided by reinforcements from other states, the replenishment of water in hydrants, and a decrease in wind speeds. (In addition to aiding the rapid spread of fires, the high seasonal Santa Ana winds earlier in the week sometimes prevented firefighting aircraft from using water and fire-retardant chemicals to control the blazes.) The bad news is that those winds may soon increase again—and in all other respects, conditions are unlikely to favor firefighters anytime soon.

Upcoming Weather Conditions

The Storm Prediction Center, a division of the National Weather Service responsible for issuing fire weather outlooks, indicates that the risk for fire conditions will remain heightened across Los Angeles as we head into the weekend.

Two additional moderate Santa Ana wind events could occur in the coming days—one early on Sunday, and possibly another on Tuesday. These gusts could promote the spread of existing fires and the start of new ones.

A Santa Ana wind event happens when there is a pressure difference between the Great Basin—the expansive area in Nevada and Utah—and coastal communities around Los Angeles.

Meteorologists often use the air pressure difference between Las Vegas and Los Angeles to predict these winds. A greater pressure difference results in stronger winds rushing toward the coast, which fuels existing wildfires. This is what forecasters expect to see again in the coming days.

Vegetation will also remain exceptionally dry throughout the region. It's currently the middle of Southern California's rainy season—yet rain is absent. After experiencing its third-wettest February on record last year, Los Angeles International Airport has reported only 0.03 inches of rain since last summer began.

Despite being prime time for Los Angeles' rainy season in mid-January, there is little hope for significant rain over the next week and a half. NOAA's Climate Prediction Center announced Thursday that we have officially entered La Niña, a pattern of cooler-than-normal water temperatures in the Pacific Ocean around the equator. Atmospheric changes in response to La Niña can shift the jet stream northward over the Eastern Pacific Ocean, directing storms to Canada's West Coast instead of the western US, depriving states like California of rain.

As expected, the main storm track across the Pacific Ocean will remain near the Gulf of Alaska through mid-January, leaving few chances for rain to reach as far south as Southern California.

Forecasters anticipate a weak La Niña will persist through the end of winter, with a fair chance the pattern will dissipate in time for spring. Unfortunately, this timing might coincide with the start of Southern California's dry season.

This doesn't mean we won't have opportunities for rain in the coming months. However, minimal to no rain through at least mid-January will keep vegetation extremely dry across the region. The ongoing risk for new fires and additional fire growth will depend on periods of low humidity with strong winds—and any further Santa Ana wind events could pose a danger in the coming weeks.