As the winds squeeze through canyons and valleys they speed up, fanning flames. The winds are also usually gusty and can change direction quickly, sending flames racing into new areas. As the winds whip over mountains and squeeze through canyons, friction helps create eddies, or swirling winds. As these come and go, the air can become almost still and then quickly speed up in gusts. The winds are like water rushing down a very rough white-water stream, creating eddies that come and go.
Fires also affect the winds.
As the flames warm the air, it rises and more air rushes into to replace the rising air, helping create more gusts.