Devastating wildfires continued to burn throughout the Los Angeles metropolitan area on Friday, extending mandatory evacuations and school closures across the region. Next week promises little chance of relief; conditions will remain favorable for both the growth of existing wildfires and the emergence of new fires, as gusty winds persist amid unusually dry conditions.
Officials reported five major fires throughout the Los Angeles area Friday morning. THE Palisades fire in Pacific Palisades and Malibu consumed more than 20,000 acres, while the Eaton Fire in Altadena spans over 10,000 acres. At least 10,000 structures were reported destroyed in Los Angeles and 10 people were killed.
Favorable fire conditions require dry vegetation, low humidity and high winds. The combination of these ingredients allows fires to start easily and spread quickly; It was this dangerous mix that allowed the Palisades Fire and Eaton Fire to expand beyond any crew’s ability to control them earlier in the week.
Since then, firefighters have managed to to start control fireshelped by reinforcements from outside the State, the water from the fire hydrants being restockedand the wind speed decreases. (In addition to contributing to the rapid spread of fires, seasonal high winds in Santa Ana earlier in the week has sometimes prevented firefighting planes from working to control fires with water and fire-retardant chemicals.) The bad news is that those winds may be about to pick up again – and that on all other fronts, conditions are probably not favorable. soon in favor of the firefighters.
What happens next with the weather
THE Storm Prediction Centerthe National Weather Service agency responsible for issuing fire weather forecasts, says the fire danger will remain high throughout Los Angeles through this weekend.
We could see two more moderate wind events in Santa Ana in the coming days: one early Sunday and another possibly Tuesday. These gusts could favor the spread of existing fires and the ignition of new blazes.
A Santa Ana wind event occurs when there is a pressure difference between the Great Basin (the vast expanse of land in Nevada and Utah) and the coastal communities around Los Angeles.
Meteorologists often use the difference in air pressure between Las Vegas and Los Angeles to predict these winds. A stronger pressure difference creates stronger winds that rush toward the coast, fueling existing wildfires. This is what they predict we might see again in the coming days.
Vegetation will also remain exceptionally dry throughout the region. We are currently in the middle of the rainy season in Southern California, and yet the rain is nowhere to be found. After experiencing its third wettest February on record last year, Los Angeles International Airport has reported just 0.03 inches of rain since the start of last summer.
Although mid-January is prime time for rainy season in Los Angeles, there is very 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 phenomenon of colder-than-normal water temperatures in the Pacific Ocean around the equator. Atmospheric changes in response to La Niña can force the jet stream to shift northward over the eastern Pacific Ocean, moving storms toward the west coast of Canada rather than the western United States. United, thus depriving states like California of rain.
Right on cue, the predominant storm track across the Pacific Ocean will remain near the Gulf of Alaska through mid-January, providing little opportunity for rain to reach as far south as Southern California.
Forecasters expect a weak La Niña to persist through the end of winter, with a good chance the phenomenon will fade in time for spring. Unfortunately, this timing may coincide with the start of the dry season in Southern California.
That’s not to say we won’t see opportunities for rain in the coming months. However, little to no rain through at least mid-January will keep vegetation exceptionally dry across the region. The continued risk of new fires and additional fire growth will depend on periods of low humidity accompanied by gusty winds – and any additional wind events in Santa Ana could prove dangerous in the coming weeks.
