Severe Fire Conditions Lead to ‘Extreme’ Red Flag Warning in Los Angeles Area

An “extreme” red flag warning has been declared in the Los Angeles area ahead of some of the worst conditions for a fire in the last 12 years.

Thousands of people have already been forced to flee the Tick and Getty Fires in the Los Angeles area, but meteorologists warn that conditions are becoming even more dangerous for extreme fire behavior — fires which spread quickly and may behave erratically — in the Ventura County Valleys, the Ventura County Mountains and Los Angeles County Mountains. National Weather Service Meteorologist Curt Kaplan warns that the area hasn’t seen such extreme conditions since 2007. That year, California faced 9,093 wildfires, according to the National Interagency Fire Center.

Kaplan explains what makes the situation so dangerous is that the region is facing four dangerous factors at once — powerful Santa Ana winds with gusts over 60 mph, very dry vegetation, very low humidity, and a long duration of favorable conditions for a fire.

Kaplan warned that that the combination means that the conditions are different than a “run-of-the-mill” red flag warning.

“It’s not terribly rare we get Santa Ana wind events this strong, but it is rare to get these conditions for a red flag warning and for extreme fire behavior,” Kaplan said.

Lisa Phillips, another National Weather Service meteorologist, tells TIME that it was unusual to see all of the conditions that forecasters watch out for to predict fires at their “peak.” The area is experiencing wind gusts of up to 65 miles per hour, with strong winds forecasted into Thursday. The landscape is unusually dry, because the region recently underwent a long drought and has gotten little rain since the winter. On top of that, the humidity is at “zero” in some locations, Phillips.

“These are dangerous conditions. Be prepared to evacuate if you need to,” says Phillips.

Experts say that California’s wildfires have become larger and more damaging in recent years. Although the causes are complex, experts say that climate change has increased the frequency of the hot and dry conditions that fuel fires, and that rising costs have compelled construction in areas at high risk for fires.