Control Winds stacking

[Toxicsyn]

If three 10th level casters cast Control Winds. Does the severity of the winds stack?

Example: Environmental condition (light winds). The first caster increase the wind level to strong winds. The second caster increase the wind level to wind storm levels. The third caster increases the wind level to tornado level strength.

[Thomas LeBlanc]

You can't cast control winds until 9th level and...

Control Winds wrote:

Wind Strength: For every three caster levels, you can increase or decrease wind strength by one level.

So right off the bat at 9th level, you can make light winds into severe winds. And a 2nd 9th level caster could increase the winds to tornado strength. Since you don't have to concentrate, there is nothing in the rules that says you can't cast the spell a second time with the same caster.

[caith]

Casts "Raise Thread"...

I would like to know if this is, in fact, possible...can you stack two castings of Control Wind together, either from the same caster or multiple casters, to increase the severity of the wind?