Control Winds

Transmutation
Circle: Shaman 7
Casting Time: 1 standard action
Range: [Medium]
Effect: Windstorm affecting everything within [Medium] range of you
Duration: [Encounter]
Saving Throw: Fortitude negates

You alter wind force in the area surrounding you. You can make the wind blow in a certain direction or manner, increase its strength, or decrease its strength. The new wind direction and strength persist until the spell ends or until you choose new ones, which requires concentration. You may create an "eye" of calm air up to 80 ft in diameter at the center of the area if you so desire, and you may choose to limit the area to any cylindrical area less than your full limit.

You may choose one of four basic wind patterns to function over the spell's area:

A downdraft blows from the center outward in equal strength in all directions.
An updraft blows from the outer edges in toward the center in equal strength from all directions, veering upward before impinging on the eye in the center.
A rotation causes the winds to circle the center in clockwise or counterclockwise fashion.
A blast simply causes the winds to blow in one direction across the entire area from one side to the other.

You cause the wind conditions in the area of the spell's effect to become any one of the conditions on the list below. Each [Round], at the start of your turn, each creature in the area of the spell's effect must make a Fortitude save against the spell. On a failed save, that creature suffers the effects of the current wind condition and all wind conditions with lower miles per hour (mph).

Strong winds (21+ mph) make maintaining a solid footing or sailing difficult. The creature treats all squares as difficult terrain when moving in the direction against the wind.
A severe wind (31+ mph) tears tiles off rooftops and causes other minor destruction. The creature is [Checked] against the direction of the wind. If it is [Flying], it is pushed back 1d6 x 10 ft.
A windstorm (51+ mph) drives most airborne creatures from the skies, uproots small trees, knocks down light wooden structures, tears off roofs, and endangers ships. The creature is [Blown away], and this spell deals 5d6 physical damage to it.
Hurricane force winds (75+ mph) destroy wooden buildings, sometimes uproot even large trees, and cause most ships to founder. The creature is [Battered].
A tornado (175+ mph) breaks buildings and bones and often uproots large trees. This spell deals 5d6 additional physical damage to the creature.