"A windstorm barreling from the east just set the stage for this week's burning disaster. It's a normal phenomenon that comes from the jet stream, which this time of year grows stronger. North and south "meanders" in the jet stream, known as troughs and ridges, get amplified.
These cold air masses travel through the Great Basin in Nevada and spill over the Sierra Nevada Mountains in eastern California. Big meanders set up very-high-pressure areas that accelerate winds.
"I always like to say nothing good comes from an east wind in California," Lareau adds.
As the air descends at an accelerating pace, it warms up and drives the relative humidity down. Which brings us to our second factor in the horror show: fuel -- lots of it. It may be November, but California is still extremely dry, which means plenty of vegetation that's primed to go up in flames.
The east winds further dehydrate the vegetation. This is where something called the evaporative demand drought index comes in. "You can think about it as how thirsty the atmosphere is," Lareau says.
"How strongly does the atmosphere want to pull water out of the vegetation and out of the ground?"
"It's hot, dry, and windy, are your ingredients," he adds. "We checked off all three here."
It was no coincidence that these fires landed all at once. "Literally the same air mass is what's causing the beginnings of a strong Santa Ana event ongoing now, as this air mass sags south through California," Lareau says.
This is what a climate change reckoning looks like. "All of it is embedded in the background trend of things getting warmer," Lareau says. "The atmosphere as it gets warmer is thirstier." Like a giant atmospheric mosquito, climate change is sucking California dry."
exerpts.... since some people can't be bothered to click the link, you know, because this is all, "a game".