Summoning up the power of the tempest, you direct a current of forceful winds where you please. This spell creates a 5-foot-diameter line of wind-the direction of the wind is away from your location when you cast the spell, and remains constant in that direction for the spell duration. Creatures caught in a river of wind take 4d6 nonlethal damage and are knocked prone. A successful Fortitude save halves the damage and prevents being knocked prone.

A creature that begins its turn wholly or partially within a river of wind must make a Fortitude save or be pushed 20 feet in the wind's direction of flow, take 2d6 nonlethal damage, and be knocked prone-a successful Fortitude save means the creature merely takes 1d6 nonlethal damage. Creatures under the effect of freedom of movement and creatures with the air subtype are unaffected by a river of wind.