Those who need more motivation to stay home to help curb the spread of the coronavirus will get some help this week from a slow-moving storm that’s expected to dampen — and at times — douse Southern California with rain.
The center of a low-pressure system lingering off the coast of the Bay Area brought widespread showers to the Southland overnight Sunday into early Monday. The bulk of the rain is expected to fall in Los Angeles County through Monday before diminishing overnight. Heavy rain will return Tuesday night through at least Wednesday evening, and some areas could see showers Thursday, said Tom Fisher, a meteorologist with the National Weather Service in Oxnard.
As of 6 a.m. Monday, the storm had dumped 1.27 inches on Beverly Hills, more than an inch in Bel-Air, more than half an inch in downtown Los Angeles and just under 2 inches in Woodland Hills. The Los Angeles County mountains got an even better soaking, having already received up to 2.5 inches of precipitation early Monday, according to the weather service.
“It’s very moisture-rich,” Fisher said of the storm. “This is more of what we expect to see in a January or February system. It’s unusual, but it’s welcome.”
The storm is expected to bring between an inch and 2 inches of rain to the coasts and valleys through Tuesday. The San Gabriel Mountains are expected to see a bit more, with forecasters anticipating between 3 and 5 inches falling along the range. Forecasters say strong wind gusts ranging from 45 to 55 mph are expected through Monday.
The rain prompted the weather service to extend a flood advisory for Los Angeles County through Monday morning, warning of rainfall rates that will cause ponding of water on roadways and local flooding in low-lying areas.
“Rainfall rates were generally between 0.20 and 0.33 inches per hour, but local rates up to one-half inch per hour have been observed,” the weather service wrote.
There is still a slight chance of thunderstorms, forecasters say, that could increase rainfall rates even more. The heavy rain could bring the threat of rock and mudslides along canyon and mountain roadways. The weather service also warned of possible shallow debris flows around the areas where the Getty and Saddleridge fires burned last year.
In anticipation of the storm and potential mudslides, Riverside County officials issued an evacuation warning for residents of Indian Canyon, where the Holy fire burned in August 2018. However, no significant damage has been reported from the storm as of Monday morning, forecasters say.
The storm is also expected to dump some much-needed snow across California’s mountains.
The Los Angeles County mountains are forecast to see heavy snow at higher elevations through Thursday, with 15 to 30 inches predicted at 6,000 feet and higher, and 4 to12 inches at 4,500 feet.
The Sierra Nevada is also expected to receive a solid dumping of fresh powder, with up to 4 feet likely above 7,000 feet and up to 3 feet up as low as 5,000 feet in the southern section of the mountain range.
The Lake Tahoe area, where surveyors with the Department of Water Resources last week measured a lackluster snowpack resulting from a mostly dry winter, could see up to a foot of snow, forecasters say.
“This storm has stronger orographic lifting than what we saw in the several systems in March,” Fisher said, meaning the storm is primed to bring more rain and snow to mountain areas. “This one is on a good trajectory to bring us significant rainfall.”