Parts of Southern California could get up to an inch of rain this week

Light showers could hit parts of Los Angeles County beginning late Monday as a low pressure system moves onshore, with some areas across the region expected to get up to an inch of rain on Tuesday, forecasters say.

The eastern end of Los Angeles County, including Azusa, could get less than a 10th of an inch of rain starting Monday after 6 p.m., said Kathy Hoxsie, a meteorologist with the National Weather Service. A slight chance of isolated thunderstorms is also forecast.

Up to an inch of rain could fall in some areas of Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties starting Tuesday evening through Wednesday morning, Hoxsie said.

The last measurable rainfall in Los Angeles County was on May 21, Hoxsie said. The total for March was 2.69, the last time the area had a good soaking.

Meanwhile, Hurricane Rosa, which is moving toward the Baja Peninsula near the U.S.-Mexico border, is expected to make landfall as a tropical storm as it moves northeast Sunday toward Arizona, bringing precipitation to Southern California.

Swells generated by the hurricane are also expected to bring high waves to the area. In Los Angeles and Ventura counties, surf could build to 6 to 10 feet high by late Sunday on south-facing beaches.

A separate system coming from Alaska is forecast to arrive late Monday into Tuesday that could bring widespread showers across the entire Bay Area and down into the Central Coast, said meteorologist Rick Canepa of the National Weather Service’s Monterey office.

Snow is possible beginning Tuesday in the Sierra Nevada above 9,000 feet, the National Weather Service office in Hanford said, with accumulations of 2 to 5 inches.

dakota.smith@latimes.com

Twitter: @dakotacdsmith

UPDATES:

5:40 p.m. This article has been updated with new information from the National Weather Service.

This article was originally posted at 11:40 a.m.