I would like to see this spell gain a little bit of power in the "knocked prone" department as the caster gains levels. Being capable of knocking prone Medium creatures with a caster level of 6+ and knocking prone Large creatures with a caster level of 12+. I have no idea if there is something like that that increases in power yet, but I would like to see one. The original spell is as follows...
Gust of Wind
Evocation [Air]
Level: Drd 2, Sor/Wiz 2
Components: V, S
Casting Time: 1 standard action
Range: 60 ft.
Effect: Line-shaped gust of severe wind emanating out from you to the extreme of the range
Duration: 1 round
Saving Throw: Fortitude negates
Spell Resistance: Yes
This spell creates a severe blast of air (approximately 50 mph) that originates from you, affecting all creatures in its path.
A Tiny or smaller creature on the ground is knocked down and rolled 1d4×10 feet, taking 1d4 points of nonlethal damage per 10 feet. If flying, a Tiny or smaller creature is blown back 2d6×10 feet and takes 2d6 points of nonlethal damage due to battering and buffeting.
Small creatures are knocked prone by the force of the wind, or if flying are blown back 1d6×10 feet.
Medium creatures are unable to move forward against the force of the wind, or if flying are blown back 1d6×5 feet.
Large or larger creatures may move normally within a gust of wind effect.
A gust of wind can’t move a creature beyond the limit of its range.
Any creature, regardless of size, takes a -4 penalty on ranged attacks and Listen checks in the area of a gust of wind.
The force of the gust automatically extinguishes candles, torches, and similar unprotected flames. It causes protected flames, such as those of lanterns, to dance wildly and has a 50% chance to extinguish those lights.
In addition to the effects noted, a gust of wind can do anything that a sudden blast of wind would be expected to do. It can create a stinging spray of sand or dust, fan a large fire, overturn delicate awnings or hangings, heel over a small boat, and blow gases or vapors to the edge of its range.
Gust of wind can be made permanent with a permanency spell.