Bootleg Fire Is So Big 'It's Changing the Weather'

You can talk about acres burned, containment, or the number of firefighters engaged, but a quote from a state forestry official in Oregon might provide the best sense of just how big the Bootleg Fire has grown: “The fire is so large and generating so much energy and extreme heat that it’s changing the weather,” says Marcus Kauffman. “Normally the weather predicts what the fire will do. In this case, the fire is predicting what the weather will do.” More on that:

• The fire is creating a rare phenomenon known as pyrocumulus clouds, per CNN. These form when a wildfire's extreme heat forces air to rise rapidly. As trees and other plant life burn, the water inside them evaporates into that rising air, per a separate explainer by CNN. "This additional moisture in the atmosphere condenses in the cooler air above, on smoke particles also produced by the fire." Essentially, the clouds become self-contained thunderstorms, complete with lightning and fierce winds.

• As the New York Times puts it, the fire is generating its own weather, which makes an already challenging task for firefighters even more difficult. "The intensity and extreme heat can force wind to go around them, create clouds and sometimes even generate so-called fire tornadoes—swirling vortexes of heat, smoke and high wind."
• As for the numbers, the 2-week-old fire has grown to 537 square miles, which makes it the fourth-largest fire in state history, per the AP. Roughly 2,000 homes have been evacuated and another 5,000 are threatened, numbers that would be far higher if Oregon were as densely populated as, say, California. The fire was 25% contained as of Tuesday morning, per the Oregonian. That's up from 22% on Sunday.

(More wildfires stories.)