Fire Weather: On the Front Lines of a Burning World

by John Vaillant

Smoke columns behave like fountains in other ways, too: suffused within that swirling vortex, inconceivable in the face of so much fire, was a colossal amount of water—not just from moisture bound up in the forest, but also from melting ice, broken water lines, and fire hoses. In order for fuels to burn as explosively as they did in Fort McMurray, any residual moisture had to be removed by evaporation. All that water has to go somewhere, and it does: what looks from a distance like “smoke” is really a combination of soot, combustive gases, toxic chemicals, and steam. Hundreds of thousands of gallons of water vapor were being carried skyward though the smoke column, ten, twenty, thirty thousand feet above the fire, where it condensed and then froze. There, miles above the city, hurricane-force downdrafts hurled fusillades of black hail back to earth, just as they had done in ancient Egypt. Reduced to their most elementary ingredients, these carbon-infused ice pellets were all that remained of the trees and houses so recently devoured by the fire.