A late-season storm dumped about three-quarters of an inch of rain onto Santa Monica on Monday amid high surf and flood advisories. 

Waterworks began at about 8:30 a.m. Monday, March 28, with trace rain expected through the night Monday and into the early morning hours of Tuesday. By 4 p.m., the National Weather Service (NWS) rain gauges recorded .81 inches of rain had fallen at Santa Monica Airport since the storm began.

The NWS predicted Santa Monica might see some showers again later in the week on Thursday morning, reporting a 20 percent chance of morning showers on March 31.

By noon on Monday, the NWS said the heaviest rain had already moved through the area.

The weather system marked a turnabout from an extremely dry winter that has spurred calls for water conservation; it was the first major rain event of the year.

Locals were warned to be careful in the ocean from 3 p.m. Monday through noon Tuesday, with a NWS high surf advisory in effect for the Los Angeles County coast. 

“There is an increased risk of drowning due to the hazardous conditions,” the advisory read. “Rip currents can pull swimmers and surfers out to sea. Waves can wash people off beaches and rocks, and capsize small boats nearshore.”

Swimmers and surfers are warned to avoid entering the water during rain events and to stay out of the ocean for up to three days following rainfall due to pollution and bacterial runoff from roadways and storm drains.

An NWS flood advisory was in effect through 11:30 a.m. Monday, with “urban and small stream flooding caused by excessive rainfall” expected throughout Ventura and Los Angeles counties. 

The storm hit the San Francisco Bay region overnight from Sunday into Monday and spread east and south.

Winter weather advisories were issued for the Sierra Nevada, where 6-12 inches of snow were expected to fall at elevations above 6,000 feet, the NWS said.

The Mammoth Mountain resort said the storm could bring some of the biggest totals in quite a while.

“Mother Nature has returned wintry weather and we couldn’t be more stoked,” the resort said on its website.

Winter storm warnings posted for Southern California mountain ranges called for similar amounts of snowfall as well as up to 18 inches at higher elevations. Bear Mountain and Snow Summit east of Los Angeles announced last week that they will remain open through April 16.

After two years of drought, California got off to a good start with heavy precipitation in October and December 2021. Then, January and February were historically dry, leaving the state’s snowpack well below normal.

Santa Monica was spared the more serious effects of rain, with no major incidents reported by the Santa Monica Police Department, Fire Department or California Highway Patrol on local roadways. 

During the heaviest rainfall, which fell mid-morning, several minor incidents were reported including a spun-out Dodge Charger on the Santa Monica (I-10) Freeway at Bundy and a stalled Crown Victoria on the I-10/405 interchange. 

Southern California Edison did not report any unplanned power outages to the Santa Monica area; the same was true for Malibu, which is much more likely to see outages and other weather-related disruptions when rain occurs. Though Las Virgenes Canyon Road saw minor mudslides, in general the rainy weather did not cause damage to the Santa Monica Mountains area. Leo Carrillo, located near the Los Angeles/Ventura county line, received nearly an inch of rain on Monday, according to an NWS gauge. 

emily@smdp.com