Firefighters at the Rocky Mountain Arsenal, a wildlife refuge in Colorado, conducted a controlled burn of 150 acres of land on March 14. While they burned the loose vegetation, a dust devil formed. The Facts on File Dictionary of Weather and Climate defines this phenomenon as "a localized whirlwind of dust in a desert area . . . caused through intense local heating of the ground surface by the Sun, which results in strong convection currents being formed."
Tumbleweeds and other pieces of brush caught on fire and were swept up in the wind, creating a terrifying vision of smoke and flame. Thomas Rogers was on hand to shoot a video of the hellscape.
-via Ace of Spades HQ
UPDATE 3/24/14: Thomas Rogers, the firefighter who shot this video, wrote a lengthy description of this unusual event at Ace of Spades HQ. He also describes the challenges and complexity of a controlled burn. It makes for fascinating reading.