Alexander Gershnov

Basically, the moisture and rain gets squeezed out of these systems right on those same slopes where the Santa Ana winds blow the hardest.

Basically, the moisture and rain gets squeezed out of these systems right on those same slopes where the Santa Ana winds blow the hardest.

Basically, the moisture and rain gets squeezed out of these systems right on those same slopes where the Santa Ana winds blow the hardest.

Specifically in that region where the wildfires are right now, you have a lot of vegetation dry and ready to burn. And that's exactly where you get the strongest Santa Ana wind.

Specifically in that region where the wildfires are right now, you have a lot of vegetation dry and ready to burn. And that's exactly where you get the strongest Santa Ana wind.

Specifically in that region where the wildfires are right now, you have a lot of vegetation dry and ready to burn. And that's exactly where you get the strongest Santa Ana wind.

Santa Ana winds are a type of downslope wind. They accelerate down the slopes of the coastal topography here. And basically, they originate in an elevated basin at about 1,200 meters behind the Sierra Nevada mountains and goes all the way to the Salt Lake. And you have... cool air masses settling into the Great Basin.

Santa Ana winds are a type of downslope wind. They accelerate down the slopes of the coastal topography here. And basically, they originate in an elevated basin at about 1,200 meters behind the Sierra Nevada mountains and goes all the way to the Salt Lake. And you have... cool air masses settling into the Great Basin.

Santa Ana winds are a type of downslope wind. They accelerate down the slopes of the coastal topography here. And basically, they originate in an elevated basin at about 1,200 meters behind the Sierra Nevada mountains and goes all the way to the Salt Lake. And you have... cool air masses settling into the Great Basin.

And when you have the pressure gradients, basically high pressure around the four corners area, you get this air mass to come over and through the passes and through the gaps in the surrounding topography, basically getting pushed towards the ocean and it basically accelerates downhill under the force of gravity. And you get these dry, gusty, downslope winds that we call Santa Ana's here.

And when you have the pressure gradients, basically high pressure around the four corners area, you get this air mass to come over and through the passes and through the gaps in the surrounding topography, basically getting pushed towards the ocean and it basically accelerates downhill under the force of gravity. And you get these dry, gusty, downslope winds that we call Santa Ana's here.

And when you have the pressure gradients, basically high pressure around the four corners area, you get this air mass to come over and through the passes and through the gaps in the surrounding topography, basically getting pushed towards the ocean and it basically accelerates downhill under the force of gravity. And you get these dry, gusty, downslope winds that we call Santa Ana's here.

Downslope winds happen everywhere there are mountains. But these winds are very special because of the geography of the southwestern United States and specifically the fact that we have this elevated Great Basin where these winds are really rooted. They're basically the breast of the desert.

Downslope winds happen everywhere there are mountains. But these winds are very special because of the geography of the southwestern United States and specifically the fact that we have this elevated Great Basin where these winds are really rooted. They're basically the breast of the desert.

Downslope winds happen everywhere there are mountains. But these winds are very special because of the geography of the southwestern United States and specifically the fact that we have this elevated Great Basin where these winds are really rooted. They're basically the breast of the desert.

The one unusual thing about this particular event is that there's a lot of what meteorologists call upper air support. And basically, it's the jet stream that's blowing in the high troposphere that happens to be meandering in such a way that it just intensifies that flow from the northeast coming right into Southern California.

The one unusual thing about this particular event is that there's a lot of what meteorologists call upper air support. And basically, it's the jet stream that's blowing in the high troposphere that happens to be meandering in such a way that it just intensifies that flow from the northeast coming right into Southern California.

The one unusual thing about this particular event is that there's a lot of what meteorologists call upper air support. And basically, it's the jet stream that's blowing in the high troposphere that happens to be meandering in such a way that it just intensifies that flow from the northeast coming right into Southern California.

All the ignitions are human-caused, and there are plenty of sources of ignition out there because population is expanding into that wildland-urban interface, that sloping topography where the Santa Ana winds blow. And a lot of the sources of wildfire ignitions are going down, things like cigarette butts and campfires.

All the ignitions are human-caused, and there are plenty of sources of ignition out there because population is expanding into that wildland-urban interface, that sloping topography where the Santa Ana winds blow. And a lot of the sources of wildfire ignitions are going down, things like cigarette butts and campfires.