Several inches of rain will soak Los Angeles and Southern California as a Pacific storm strengthens with the risk of flash flooding, debris flows, and travel delays expanding inland over the Southwest.

An atmospheric river sweeping California is bringing some rain to the southern part of the state, with more than 20 million people under flood watch advisories.

Forecasters said most of the area will receive between 3 and 6 inches of rain before the dual systems move out of the region Sunday.