LOS ANGELES -- When Forest Service meteorologist Tom Rolinski heard that a wildfire had broken out Monday evening in Ventura County, he knew it was going to be a problem.
The Thomas fire started in a known wind corridor on the first day of dry Santa Ana winds that are expected to buffet Southern California for nearly a week. What's more, it has been a good eight months since a decent rainfall soaked the chaparral hillsides.
"Fires will spread very rapidly in these conditions and basically will be uncontrollable," Rolinski said.
The blaze was the latest in a series of wildfires that are searing 2017 into the state's record books. They all have had one thing in common -- winds that quickly turn a fire into an inferno.
More than drought or heat, winds can determine whether California burns or doesn't.
October's devastating Northern California wildfires exploded on a night when Diablo winds raged across parts of eight counties, tossing embers into Santa Rosa and ultimately claiming 44 lives.
Southern California managed to escape major wildfires during the final years of the state's big drought because the Santa Anas didn't blow much.
But this year is different. Fire meteorologists predicted an above-average number of Santa Ana wind days this fall and winter.
There were 14 Santa Ana days -- more than twice the norm -- in October, when the Canyon 2 fire in Orange County burned dozens of buildings. December typically brings 10 Santa Ana days. By the end of the week, the region will already have been hit by six of them.
The fire danger is expected to be greatest on Thursday, when the online Santa Ana Wildfire Threat Index forecasts an extreme fire threat all the way from Ventura County to the Mexican border.