Santa Ana winds are expected to again batter the Southland this week, with localized gusty conditions and low humidity developing as early as Tuesday evening, followed by more widespread winds that will heighten the risk of wildfires.
The National Weather Service issued a fire weather watch for the valleys and mountains of Los Angeles County that will be in effect from late Wednesday night through Friday afternoon, thanks to the combination of gusting winds and low humidity. In Orange County, a more serious red flag warning — denoting conditions ripe for wildfires — will be in effect from 6 p.m. Wednesday to 10 p.m. Saturday for the Santa Ana Mountains and inland areas, including Anaheim, Santa Ana, Garden Grove, Irvine, Orange, Fullerton and Mission Viejo.
“The strongest winds are forecast to occur after sunset Wednesday night and continuing through Friday morning,” National Weather Service forecasters said of the Orange County conditions. “Winds will continue quite strong through through Saturday and it is this combination of strong winds and very low relative humidity that will result in this extended period of critical fire weather conditions over the mountains and valleys.”
In Los Angeles County, NWS forecasters said critical fire weather conditions will develop off and on over the next week, including Tuesday night in some areas that could see 30 to 45 mph winds and humidities as low as 5%.
“A significant strengthening Santa Ana event is still on target to form Wednesday night through Thursday, then continue into Friday with slow and gradual weakening through the weekend,” according to the NWS. “Gusts should peak between 45 and 65 mph … , with minimum humidities between 8 and 15 percent on Thursday, and 5 and 10 percent on Friday through Sunday.”
Forecasters said red flag warnings could be issued in the Los Angeles area as early as Wednesday evening, potentially continuing through Friday or Saturday.
“There is a chance for red flag conditions to persist through as late as Tuesday as the dry air persists, but there remains a lot of uncertainty in the wind projections,” according to the NWS.
The fire weather watch will affect the San Fernando and Santa Clarita valleys and the Santa Monica Mountains Recreational Area.
The wind event will again raise the possibility of power outages. Southern California Edison warned Tuesday that some customers could be subject to Public Safety Power Shutoffs, in which electricity is cut in particularly wind-affected areas to prevent equipment damage that could spark fires.
“We understand that having your power turned off is a hardship, especially in the middle of a pandemic and when most folks are at home. We are working to limit the number of customers who are shutoff due to Public Safety Power Shutoffs,” Vik Trehan, SCE director and incident commander, said in a statement. “We know this is especially difficult for customers who lost power due to PSPS over the Thanksgiving holiday and who live in areas with high winds and increased wildfire threats. These PSPS are initiated to reduce the risk of wildfires and to protect communities from wildfire danger.”
Residents can get more information about the shutoffs, and determine if they are in an area being considered for power cuts, by visiting www.sce.com/psps. As of Tuesday, the utility listed 33,415 customers in Los Angeles as being under consideration for possible shutoffs, along with 22,395 in Orange County.