LOS ANGELES - Another Santa Ana wind system was setting up over the mountains and canyons of Southern California today, and red flag warnings were posted at midmorning to extend into Tuesday night.

Sustained winds of 20 miles per hour may gust to 50 mph today and through Tuesday in the mountains of Los Angeles and Ventura counties, including the Santa Monica Mountains and Hollywood Hills, the National Weather Service predicted.

The Santa Clarita Valley was included in the high-wind warning zone.

Coastal and valley areas should experience winds of 15-25 miles per hour, with gusts to 40 mph, the National Weather Service warned.

Humidity readings were expected to drop into the single digits, as dry air from inland deserts was squeezed towards the coast through mountains, canyons and passes.