Southern California is facing fierce fires fueled by the Santa Ana winds, which threaten homes and put firefighters to the test.

Southern California will continue to face "dangerous fire weather conditions" including strong Santa Ana winds and extremely low humidity through later this week, forecasters said Tuesday.

A rare Particularly Dangerous Situation warning has been issued for Southern California as a powerful and potentially damaging Santa Ana wind event​ is expected.

Millions of California residents were placed under a red flag warning through Thursday amid threats of further fires with looming winds in the forecast, according to multiple reports.

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. When conditions are dry, as they are right now, these winds can become a severe fire hazard.

California Governor Gavin Newsom has deployed fire engines, water-dropping aircraft and hand crews across the region—to enable a rapid response if a new fire does break out, according to The Associated Press.

Forecasters in Southern California expect to issue a 'particularly dangerous situation' red flag warning for the coming week as the Santa Ana wind forecast worsens.