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

As the relentless Santa Ana winds sweep through, a new fire threat emerged in Jurupa Valley, leaving residents on edge and firefighters racing against time.

RIVERSIDE COUNTY, Calif. - A fire broke out in Jurupa Valley as the Santa Ana winds continued to linger around Southern California.

Several counties in Southern California faced "critical" fire risks this week, according to an AccuWeather forecast.

The Santa Anas are expected to be most powerful Monday night into Tuesday. Fire services across the region say they are ready.

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

Santa Ana winds return to Southern California from Monday to Tuesday, once again raising fire danger concerns.

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.

Critical fire conditions are expected to continue through Friday. But rain could be on the way this weekend. Here's what to know.

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.

The backstory: Russian thistles, better known as tumbleweeds, arrived in South Dakota in the 1870s most likely via a shipment of flaxseeds from Russia that was contaminated with the invasive seeds. Read on... for more on what scientists are doing to combat the invasive species.

Weekend rains could bring some relief to Southern California. Here's the forecast and an assessment of how much it will help reduce fire risk.