LOS ANGELES (KABC) — A trio of storms is expected to move across Southern California beginning on Sunday, bringing colder winter temperatures and significant rainfall to the valleys and inland areas and snow to the mountains.

The first storm is expected to be the heaviest and produce the greatest overall rainfall totals, with forecasts calling for about 1 to 3 inches in coastal and valley areas and 2 to 5 inches in the mountains by late Monday, according to the National Weather Service.

A flood watch was issued for a wide swath of Los Angeles County from Monday morning through Monday evening. Rock and mud slides are possible near steep terrain, and debris flows are possible on burn scars.

“Those living in areas prone to flooding should be prepared to take action should flooding develop,” forecasters said.

Rainfall is expected to decrease in intensity on Monday night into Tuesday, though scattered showers could linger as colder air moves into the region, forecasters said.

Snow levels are forecast to drop from around 6,500 feet early in the storm to near 5,000 feet on Tuesday.

A second storm system is expected to arrive Tuesday night into Wednesday, bringing colder temperatures and the potential for additional rain and mountain snow. Forecasters said snow levels could fall as low as 2,500 to 3,000 feet at times, creating possible travel hazards on mountain roads.

An additional 1.5 to 3 inches of rain is likely on Tuesday and Wednesday, with a possibility of 3 to 6 inches of total rain in the mountains, according to the NWS meteorologists.

Temperatures will drop sharply beginning Monday, with daytime highs remaining in the mid-50s in most of Los Angeles and Orange County all week, and dropping to the low 50s and even upper 40s in the Santa Clarita and Antelope valleys.

Overnight lows will be in the 40s in most areas, but will drop into the 30s in the mountains, Santa Clarita Valley and the high desert from Tuesday to Friday.

Thunderstorms combined with strong winds and rough seas could also create dangerous marine conditions early next week, forecasters said. The third storm system is expected on Thursday, but meteorologists say the moisture levels are unconfirmed.

Copyright 2025, City News Service, Inc.