California rain
© Allen J. Schaben / Los Angeles Times
Heavy rain that pounded the Southland overnight shattered rainfall records across Los Angeles County and triggered a mudslide in Sherman Oaks that damaged at least one home.

A low-pressure system that originated in the Gulf of Alaska dumped half an inch to nearly 3 inches of rain across Los Angeles, Orange, Ventura and Santa Barbara counties between Sunday afternoon and Monday morning, said Kristen Stewart, a meteorologist with the National Weather Service in Oxnard.

Heavy rain was falling across Sherman Oaks shortly after 10 p.m. Sunday when Los Angeles Fire Department crews responded to reports of flooding at a home in the 15500 block of Hamner Drive.

When crews arrived, they discovered a debris flow that had damaged the property, said Nicholas Prange, a spokesman for the Los Angeles Fire Department.

The extent of the damage to the home was not immediately clear. No one was injured in the debris flow.

The persistent rain also brought enough moisture to rewrite the record books in some areas of Los Angeles County, Stewart said.

Los Angeles International Airport received 1.73 inches of rain Sunday, shattering the record for the day of 0.82 inches set in 2005. A record of 1.51 inches of rain fell in downtown Los Angeles, breaking the prior record of 1.11 inches set in 1975.

Just over half an inch of rain fell in Lancaster on Sunday, breaking the prior record for the day of 0.41 inches set in 1958. Palmdale Airport, which received 0.45 inches, also nudged past its record of 0.43 inches for the day, set in 2018.

The rain is expected to taper off by Monday afternoon, making way for partly sunny skies on Tuesday and Wednesday. But don't put away those umbrellas just yet.

Another system is expected to move into Southern California by Wednesday night, dampening the area through Thursday. However, rainfall totals with that storm are expected to be much lighter, with most areas in Los Angeles receiving less than a quarter-inch, Stewart said.

"We're getting to the end of March, so we're nearing the end of the rainy season," she said.

The series of March storms has proved helpful in dampening Los Angeles and keeping swaths of Southern California from sinking deeper into drought conditions following a bone-dry start to 2020.

About 11.64 inches of rain has fallen on downtown Los Angeles this water year, just slightly behind the normal 12.88 inches the area typically receives. The area was much further behind before the March rains, Stewart said.

As of last week, roughly 75% of the state was considered to be abnormally dry, down from 78% a week earlier. The portion of the state considered to be in moderate drought conditions dropped slightly as well, down to about 47%, according to the U.S. Drought Monitor.