Flood Watches are posted for the Los Angeles area burn scars left from the Palisades and Eaton fires as the first rain in weeks pushes into Southern California.
LOS ANGELES — The first significant rainfall in several months will spread across Southern California this weekend, giving a badly needed sip of water to an area parched by drought and devastated by multiple raging wildfires.
But with the rain comes a cost: Potential mud and debris flows where the scars remain from those wildfires that have scorched tens of thousands of acres and left neighborhoods in ruins.
An upper level low will swing in off the Pacific Ocean, bringing a few showers on Saturday afternoon as it approaches the coast. Most of the showers will keep rain rates in manageable ranges of around 0.10 inches or less per hour.
Southern California Rain Forecast
“This is not all day rain. It’ll be a lot of on and off showers throughout the day,” said FOX Weather Meteorologist Ari Sarsalari. “They’re a little bit hit or miss, but very high likelihood that you’re going to get wet at some point.”
Rain showers will increase in intensity and coverage as the low pushes inland on Sunday afternoon and the atmosphere becomes more unstable. That’s when the rain may become too much of a good thing in some spots, especially if it comes in heavy spurts. The National Weather Service gives a 15-25% chance of thunderstorms across the region, which could bring periods of heavy rainfall that could overwhelm the burn scar areas.
Flood Watches are now in effect from 4 p.m. Sunday through Monday afternoon for potential flash flooding in the burn scar areas left behind by the deadly Palisades and Eaton Fires, as well as the charred areas from the recent Franklin, Hughes and Bridge fires.
The NWS calculated a 10-20% chance of “significant” debris flows in the sensitive Los Angeles area burn scars.
“Just a short period of moderate rainfall on a burn scar can lead to flash floods and debris flows,” the National Weather Service said. “Rainfall that is normally absorbed by vegetation can run off almost instantly. This causes creeks and drainage areas to flood much sooner during a storm, and with more water, than normal.”
Los Angeles metro area rainfall forecast.
In addition, soils inside burn scars can contain significant amounts of mud, boulders and vegetation. And officials warned that charred hillsides are in danger of giving way even if there isn’t rain. The burned landscape, littered with broken water mains, and the influx of water from firefighting efforts have further destabilized hillsides in the region.
The sun-kissed Los Angeles area isn’t known for getting much rain, only averaging about 12 inches per year, but this dry stretch has been remarkable even by their standards.
(FOX Weather)
Just a few minutes of moderate rain this weekend will likely quickly qualify the day as the city’s wettest day since last spring. Los Angeles’s LAX Airport has only seen three days with measurable rain — and just a paltry 0.01″ each day at that — since May 5.
Downtown Los Angeles hasn’t fared much better, netting just five days with measurable rain totaling 0.16 inches since May 5.
Recent rain benchmarks for the Los Angeles area, taken at the Downtown Los Angeles weather station at USC.
About 0.50-1.00 inches of rain are expected around the Los Angeles area by the end of Monday, with 1-2 inches of rain in the mountains, though the higher elevations will pick up some snow.
“Keep in mind there’s a pretty significant drought going on. And this isn’t going to be the kind of rain that’s going to bust the drought overnight,” Sarsalari said. “We would need like a foot of rain to bust the drought, and you wouldn’t want that to happen in one event anyway. But this will be about 1 to 2 inches for a lot of people.”
But the storm’s rain and increased humidity will only help the thousands of firefighters still trying to douse the lingering flames of multiple fires still burning in the region.
The Eaton Fire is at 95% containment while containment on the Palisades Fire is now up to 79% according to fire officials. The Hughes fire burning north of Los Angeles is at 79% containment after scorching over 10,000 acres.
Current Southern California Wildfires Status
A new wildfire, dubbed “Border 2,” erupted Friday near Chula Vista, just 9 miles southeast of San Diego, prompting early morning evacuation orders.
The blaze, currently spanning over 6,200 acres with low containment near the U.S.-Mexico border, had forced schools to close in the area as residents flee for safety. Nearly 700 firefighters are now on the scene battling the blaze, according to San Diego County Fire.
The long range forecast returns to drier weather next week, but unlike the past several weeks, there doesn’t appear to be any dangerous levels of Santa Ana winds returning anytime soon.