National Weather Service issues rare blizzard warning for LA mountains
Powerful winds battered much of the Southland early Wednesday as the front end of a cold winter storm system moved into the area, giving the region a taste of the chilly temperatures, high winds, rain and snow to come — prompting an unprecedented blizzard warning for the Los Angeles County mountains.
Winds began blasting large swaths of the area Tuesday night, rattling windows while knocking down trees and power lines in parts of the South Bay. A tree even fell onto some cars and an apartment building in Manhattan Beach.
High surf, meanwhile, pounded the coast, prompting the closure overnight of the Redondo Beach Pier due to the large waves.
The National Weather Service issued a high surf advisory that will remain in effect for all Los Angeles County beaches until at least 3 a.m. Thursday. Forecasters said waves of up to 12 feet were anticipated, along with powerful rip currents that "can pull swimmers and surfers out to sea." Forecasters also warned of possible coastal flooding.
The windy conditions that greeted many residents Wednesday morning were expected to diminish, "but it will still be a cool blustery day with a chance of showers mainly over the mountains," according to the National Weather Service.
"An unusual winter storm will approach the area Thursday and will then produce periods of heavy rain and heavy mountain snow to the region Friday through Saturday night," forecasters said.
The winter storm is expected to pack a punch, even prompting the NWS to issue a rare blizzard warning that will be in effect for the Los Angeles County mountains from 4 a.m. Friday to 4 p.m. Saturday. Forecasters said up to 5 feet of snow could accumulate in the mountains, accompanied by wind gusts topping 55 mph. Higher elevations could see as much as 7 feet of snow, with accumulations of 6 to 12 inches possible at elevations between 2,000 and 4,000 feet, "including most major mountain passes."
"Travel should be restricted to emergencies only," according to the NWS. "If you must travel, have a winter survival kit with you. If you get stranded, stay with your vehicle."
According to the NWS Los Angeles office — which is actually based in Oxnard, this is the second time it has ever issued a blizzard warning for the area. The agency previously issued a blizzard warning on Feb. 4, 1984.
Ahead of the blizzard warning, a winter storm warning will be in effect in the mountains until 4 a.m. Friday for the mountains, thanks to anticipated "low elevation snow, strong winds and very cold wind chills." In the Antelope Valley, a winter weather advisory will be in effect until 4 a.m. Friday, with forecasters anticipating 3 to 6 inches of snow in the foothills and 1 to 3 inches on the valley floor, with winds gusting to 45 mph.
Forecasters said Wednesday afternoon and evening should be relatively calm in terms of weather, with lingering winds being the primary issue. Temperatures will also remain chilly, with coastal and valley areas hovering in the 40s and 50s. The snow level could fall as low as 1,500 feet in the foothills, with the possibility of accumulating snow on the Grapevine section of the Golden State (5) Freeway.
When the brunt of the storm begins to arrive Thursday, all major mountain passes will be at risk of snow, while other areas could get up to a half-inch of rain.
By Thursday night, however, things will begin to worsen.
"This system will bring a broad swath of moderate to locally heavy rain and snow (to) the area," according to the NWS. "... Snow levels will fluctuate quite a bit as the southerly flow will raise levels to about 4,500 feet briefly on Friday afternoon. This could create a mixture of rain/snow at the I-5 Grapevine area before precipitation turns back to all snow Friday evening. Rainfall rates will range from 0.50 to 1 inch per hour near the main precipitation band on Friday bringing a threat of urban flooding and issues near recent burn scars."
Coastal and valley areas could get between 2 and 4 inches of rain during the storm. But snow will be the bigger story, with the low elevation snow contributing to what could be "the largest amount of 24-48 hour snowfall seen in decades, likely rivaling the 1989 storm, for our Ventura and Los Angeles County mountains," according to the NWS.
"Snowfall of this rate and amount could lead to damage to structures and trees with an immense threat of avalanches, especially in the eastern San Gabriel Mountains by Saturday," forecasters said.
Temperatures will be in the 40s and 50s in most of the area, although they will drop into the 30s in the mountains and some valley areas, particularly at night, and into the 20s in the Antelope Valley.