SoCal To See Year's Biggest Storm Yet: How Much Rain To Expect

SOUTHERN CALIFORNIA — Cupid is bringing more than just love and chocolate this Valentine’s Day as rain is set to soak the Southland most of this week.

Following a few days of reprieve from light rain, Southern Californians are being warned to brace for the season's biggest storm yet, weather experts say.

A major atmospheric river storm is expected to arrive Wednesday and last possibly through Friday night. It could bring significant rain — about 2 inches — to many areas, from Los Angeles to San Diego County. The local mountains can also expect the heaviest snowfall of the year so far.

Much of the Southland will begin seeing evidence of the storm arriving from NorCal on Tuesday, as temperatures cool, clouds knit together and wind gusts pick up. Rain will begin falling in most areas on Wednesday, but the heaviest downpour is expected to hit Thursday and Thursday evening.

"This atmospheric river will bring with it multiple inches of rain from the North Bay Area all the way down the coast to San Diego," said AccuWeather Meteorologist Jacob Hinson. "Most areas will see 1-2 inches of rain from early Wednesday morning through Friday night. Typical upslope areas could see as much as 2-3 inches for the duration of the event."

The storm will bring multiple inches of needed rain to the region, but the storm also raises fears of major mudslides and other hazards in areas scarred by recent fires.

"Additionally, there is a chance that rainfall totals could be even higher," the National Weather Service warned.

The looming threat of the region's first big storm this season has also prompted flood warnings.

"While this rain will be beneficial to areas like the Central Valley and L.A. Basin, it could be too much of a good thing in certain areas. We’re still concerned about burn scars getting enough rainfall to affect soil stability, thus causing landslides or debris flows. The amount of rain in the forecast can also cause issues where drainage systems aren’t adequate, causing localized flooding of streets and roadways," Hinson told AccuWeather.

RELATED: Amid La Nina, SoCal Returns To Drought With Record Dry Weather

The storm is also expected to moderately douse San Diego and Orange counties as well as the Inland Empire.

"Rain will be heavy at times and snow will be confined to the highest mountains. Dry and warmer weather is expected over the weekend," NWS forecasters in San Diego said.

In Riverside County, forecasters were reporting a 90 percent chance of greater than an inch of rain for the valleys and a 65 percent to 90 percent possibility of coastal mountain slopes receiving at least 2 inches of rain.

In Orange and San Diego counties, the rain could arrive a little earlier along the coast on Tuesday.

As the rain arrives in SoCal, some snow could fall at 5,500 feet Wednesday morning before snow levels rise to more than 7,000 feet on Wednesday, increasing to 8,000 feet late Thursday, according to the NWS.

The storm also brings a 5-to-10-percent chance of thunderstorms on Thursday and Friday for the entire region, the National Weather Service said.

And while this week's storm is expected to be the strongest yet, it likely won't surpass storms that pummeled the Southland at the start of 2023, the Los Angeles Times reported. That storm triggered hundreds of mudslides from the Hollywood Hills to Malibu and evacuations in Montecito and killed two people.

The incoming atmospheric rivers will be just the third significant rain event since winter began. Last week's storm brought less than an inch of rain to most areas.

The Southland recorded its driest start to a rainy season in modern history as the state fell back into drought conditions, weather experts told Patch.

This week's storm is expected to bring further relief to bone-dry Southern California, which is still in high fire season. The region will need to get at least 2 to 3 inches of rain for high fire season to transition to low fire season, according to the Los Angeles Times.

Downtown LA has gotten about 2 inches of rain since the rainy season began in October. The typical average halfway through the wet season is 7.93 inches, the Times reported.