A major storm system arriving early Monday morning in Los Angeles County is expected to bring freezing temperatures to Antelope Valley and mountainous areas.
Based on the National Weather Service forecast, the county health official issued a cold weather alert for the Lancaster and Mount Wilson areas beginning Tuesday and Wednesday. Wind chill temperatures should be below 32 degrees.
“These inland valleys and mountainous areas will be quite cold behind this system,” said Todd Hall, NWS meteorologist in Oxnard.
Vulnerable populations should seek shelter or public facilities for warmth, said LA County health officer Muntu Davis. The LA Homeless Services Authority has a winter shelter program; information can be found at lahsa.org or by calling the county information line at 211.
“Children, the elderly and people with disabilities or special medical needs are particularly vulnerable in cold weather. Extra care should be taken to make sure they don’t get too cold when outside,” Davis said.
Light to moderate rain is expected to begin early Monday morning, with heavier precipitation later in the day, Hall said.
The Weather Service issued a flash flood watch for much of LA County Monday through Tuesday evening.
“That’s when we expect the precipitation to get heavy,” Hall said.
Urban flooding is possible and small streams can overflow their banks. There is a possibility of thunderstorms, which have the potential to bring even heavier showers, he said. The weather service forecast 2 to 4 inches of rain along the coast and valleys and 4 to 8 inches in the mountains.
At the height of the storm, rainfall could reach 1 inch per hour.
The ground in Southern California is waterlogged after weeks of successive storms, making flooding more likely.
“We’re seeing saturation in some watersheds and we’re starting to see more excessive runoff,” Hall said.
Residents should be on the lookout for debris flows in the Fish Lake, Route, Bobcat and Ranch burn areas.
Snow is expected to fall above 7,500 feet and high altitude wind gusts could exceed 70 miles per hour.
“It will be a windy system, with strong surf at local beaches and very strong winds in the mountains,” Hall said.
Another storm is expected to hit Southern California next weekend.
Los Angeles Times