Much of the Southland was enjoying a respite Tuesday from powerful winds that had been blasting the region, but even stronger and “particularly dangerous” Santa Ana conditions were expected to return by Wednesday morning, leading to more warnings of critical fire threat.
Many valley and mountain areas spent Monday under red flag wildfire conditions as Santa Ana winds blew through the region and humidity levels dropped to critically low levels. But National Weather Service forecasters said that was only a taste of what’s to come.
“There is increased confidence of a stronger, more widespread, and longer duration Santa Ana wind event which will likely bring widespread critical fire weather conditions to many wind prone areas of Los Angeles and Ventura counties Wednesday into Thursday,” according to the NWS, which called the forecast a “Particularly Dangerous Situation red flag warning event in many areas.”
The strongest winds are anticipated Wednesday “when widespread damaging wind gusts of 60 to 80 mph are likely in the mountains and foothills of Los Angeles and Ventura counties (including the Santa Monicas and Santa Susanas), with isolated gusts of 80 to 100 mph possible in favored areas of the San Gabriels. Similar winds are expected once again in the mountains Thursday night.”
“For wind prone coastal and valley areas of Los Angeles and Ventura counties, damaging gusts of 50 to 70 mph will be likely (including the Malibu coast and Ventura County coastal plain),” according to the NWS. “Due to the strong upper level wind support, typical wind sheltered areas such as portions of the L.A. basin all the way to the coast, Lake Casitas and Ojai, as well as the Channel Islands and Catalina Island are expected to see gusty north to northeast winds with associated red flag conditions.”
Forecasters said humidity levels are expected to drop to 8% to 15% by Wednesday afternoon, continuing into Thursday, giving the region a dangerous combination of dry, windy conditions.
Red flag warnings of critical fire conditions will be in effect:
— from 2 a.m. Wednesday until 6 p.m. Thursday in the Antelope Valley;
— from 11 a.m. Wednesday until 6 p.m. Thursday for L.A. County beaches and the Palos Verdes Hills;
— from 2 a.m. Wednesday until 11 a.m. Friday in the Santa Monica Mountains Recreational Area, San Gabriel Mountains and the Antelope Valley (14) Freeway corridor, with a “Particularly Dangerous Situation red flag warning” in effect in those areas from 9 a.m. Wednesday until 9 a.m. Thursday;
— from 2 a.m. Wednesday until 11 a.m. Friday in the Golden State (5) Freeway corridor;
— from 2 a.m. Wednesday until 6 p.m. Thursday in the Santa Clarita Valley, Malibu Coast and San Fernando Valley, with a “Particularly Dangerous Situation red flag warning” in effect in those areas from 9 a.m. Wednesday until 4 p.m. Wednesday;
— from 2 a.m. Wednesday until 6 p.m. Thursday in Calabasas, Agoura Hills, the Antelope Valley Foothills and the San Gabriel Valley; and
— from 11 a.m. Wednesday until 6 p.m. Thursday for Catalina Island and the L.A. County inland coast, including downtown Los Angeles.
Orange County coastal areas will be under a red flag warning from 11 a.m. Wednesday until 6 p.m. Thursday, while the Santa Ana Mountains will be under red flag warnings from 4 a.m. Wednesday until 6 p.m. Thursday.
“This is a dangerous fire weather event. Any new fires in the red flag warning area will have rapid fire spread, extreme fire behavior, and long range spotting,” forecasters said.
Due to the forecasted winds, the California Highway Patrol announced that Topanga Canyon Boulevard will be closed to non-residents between Mulholland Drive and Pacific Coast Highway from 6 a.m. Wednesday until 6 a.m. Friday. The CHP also issued a wind advisory throughout the Antelope Valley, including the 14 Freeway from Ward Road to the Kern County line, urging caution by people driving high-profile vehicles or campers or hauling trailers.
As is typical with Santa Ana wind events, Southern California Edison officials warned that some residents may be subjected to “Public Safety Power Shutoffs,” in which electricity is cut to some areas experiencing particularly high winds to reduce the possibility of fires being sparked by damaged equipment.
Thanks to Tuesday’s brief break from the winds, no such shutoffs were in effect as of mid-morning Tuesday. But the utility was warning nearly 47,000 customers in Los Angeles County and more than 8,100 in Orange County that they were under consideration for cuts once the gusting winds return Wednesday.