It should be a generally dry, yet cool, weekend across the Southland, but conditions are expected to change dramatically by Monday night, when a strong storm system is expected to drench much of the region with rain and cover mountaintops with snow through Tuesday.
National Weather Service forecasters on Thursday dubbed it “the most significant storm of the season.”
“A powerful storm system will bring periods of heavy rain and high elevation snow Monday and Tuesday before dry weather returns mid week,” according to the NWS.
Temperatures will remain on the chilly side through Saturday, with temperatures staying below normal and leading to freeze or frost warnings for some areas, particularly the Antelope Valley and the Santa Clarita Valley, forecasters said.
Conditions will warm slightly on Sunday, but still below normal, ahead of the storm system set to arrive in the Southland by Monday afternoon and evening. The brunt of the storm is expected on Tuesday.
While the storm system is believed to have weakened slightly over the past couple days, NWS forecaster said it is “still a potent system with healthy rainfall rates expected.”
Coastal areas and the valleys could get up to 3 inches of rain during the storm, while mountains and foothills could see up to 5 inches.
“Rain rates still have a good chance of at least reaching the lower end of established debris flow thresholds,” according to the NWS. “Thunderstorms are not currently in the forecast but can t be completely ruled out…”
Snow will fall on mountains above 7,000 feet, but the snow level could fall as low as about 4,500 feet by late Tuesday depending on the amount of moisture still in the storm system.
Meanwhile, following the rain that fell in the area on Thursday, an advisory issued by the county Department of Public Health will remain in place until at least 12:30 p.m. Sunday, warning people not to enter the ocean water near discharging storm drains, creeks and rivers due to bacteria or other harmful material that can be carried to the coast by stormwater.