Although Northern California will likely see the worst from the massive storm headed toward the state, Southern California residents should prepare for significant hazards, forecasters say, with flooding, high winds and dangerous surf expected in the region through Friday.
Los Angeles County has already issued evacuation warnings for residents in the northern mountains close to perilous burn scars and has closed at least one roadway in preparation for heavy rainfall.
“The heaviest rain may be focused on Northern California, but as far as the Southland is concerned, this will be the strongest storm this season so far, hands down,” said David Sweet, a meteorologist with the National Weather Service in Oxnard. “It could be very hazardous and people need to respect the level of hazard that this storm is going to bring.
“There’s enough concern with this system that everyone needs to stay on guard,” Sweet said. “Significant flash flooding and debris flows are possible, especially in and below recent burn scars.”
In L.A. County, the National Weather Service is most concerned about flooding in the Lake fire burn scar area around Lake Hughes, northwest of the Santa Clarita Valley, and the Fish fire burn areas in Duarte, Sweet said. The whole county remains under a flood watch beginning Wednesday afternoon and continuing through Thursday.
Flash flood warnings have also been issued in Ventura, San Luis Obispo and Santa Barbara counties, and parts of Orange, Riverside and San Bernardino counties.
Los Angeles County warned residents near the Lake fire and north end of the Bobcat fire burn scar areas in and around the Angeles National Forest to “be ready” for possible evacuations beginning at 1 p.m. Wednesday, “due to the potential for mud or debris flows.”
Light rain and scattered showers fell in some parts of Southern California early Wednesday, but forecasters expect more intense rain later this evening. The heaviest rainfall is likely to coincide with rush hour Thursday morning.
“It’s going to be a difficult commute Thursday morning,” Sweet said. Rainfall in the L.A. area is expected to fall at a pace of up to 1 inch per hour Thursday morning, with the most intense downpour lasting for about three hours, he said.
Throughout the storm, most of L.A. is expected to get 2 to 4 inches of rain, while the mountains could see up to 8 inches, Sweet said.
Once the worst of the cold front passes through by about mid-day Thursday, “the rainfall intensity should lessen, and turn to showers Thursday afternoon,” Sweet said.
The storm will also bring strong winds across the region, dangerous surf to the coast and significant snowfall in the mountains, Sweet said. A winter storm warning is in effect for the Los Angeles, Ventura and San Bernardino County mountains, with up to 2 feet of new snow expected for some of the highest regions, with gusts of wind reaching 60 mph.
“Even in the lower elevations, we’ll be looking at wind gusts at 40 to 50 mph, very strong winds,” Sweet said, which means possible power outages, downed trees and other debris concerns.
Light rain showers & drizzle affecting parts of southwest California. Rain still on track to pick up a bit in coverage and intensity thru the day (including PM commute), before the heavy rain moves thru tonight and Thu. Plan for delays on roads. Stay safe neighbors. #cawx #larain pic.twitter.com/19Ybev8Eit
— NWS Los Angeles (@NWSLosAngeles) January 4, 2023
Along with the possibility for flooding, Sweet said “there’s a lot of opportunity for blocked roads, unfortunately.”
Beaches in L.A. and Ventura could see waves well over 10 feet with dangerous rip currents, Sweet said, with some coastal flooding expected.
Los Angeles County is offering sandbag pickup at a number of locations.
