The National Weather Service has again posted flash flood watches for many parts of southwestern California because a very moist subtropical airmass remains in place.

Meteorologists say daytime heating Thursday will destabilize the atmosphere, allowing showers and thunderstorms to develop. With so much moisture in the atmosphere, intense rainfall is possible from any thunderstorm.

Watch areas include the mountains of Kern, Los Angeles, Ventura, Riverside, San Bernardino and San Diego counties, and desert areas including the Antelope, Apple, Indian Wells, Lucerne and Coachella valleys.

The Santa Monica Mountains are excluded from the watch areas.

Source: Associated Press