The National Weather Service has issued a Red Flag Warning for most of San Diego County amid another round of Santa Ana winds.

Smoke from wildfires in Los Angeles is drifting to the San Diego region, causing a dip in air quality and prompting North County fire officials to issue a smoke advisory.

Helping drive the wildfires in the US city of Los Angeles are the so-called Santa Ana winds, a weather phenomenon known to dry out "the hills and the nerves to

Santa Anas winds blustered the inland valleys and mountains Thursday amid a continued Red Flag Warning, with some areas in the region experiencing wind speeds over over 75 mph.

The Santa Ana winds are dry, powerful winds that blow down the mountains toward the Southern California coast. The region sees about 10 Santa Ana wind events a year on average, typically occurring from fall into January.