Tens of thousands have fled their homes as a brush fire in the Pacific Palisades has burned nearly 20,000 acres as of Thursday. Fire crews are actively working to contain the flames and stop any forward progress.

Forecasters are warning of a “life-threatening and destructive” windstorm expected to last several days and affect a massive swath of Southern California beginning early Tuesday. The offshore winds will be dry,

High pressure is building from the north and that will help to tighten the pressure gradient over southern California, producing more gusty winds.

Winds have begun shifting to the east, which drove the Eaton fire toward Arcadia and Monrovia early Wednesday morning. Smoke will more likely begin to blow into the eastern San Gabriel Valley, not as much to the south of the fire, Lyou explained. “Arcadia, Duarte and Azusa may see elevated levels (of bad air) from that fire,” he said.

Although the strongest wind gusts have passed through the Southern California region, another "traditional Santa Ana wind event" will move in Thursday night.

What are the Santa Ana winds? Santa Ana winds are created when large areas of high pressure become established over the Great Basin in the interior of western America, which inclu