What kind of action must an Air Elemental take to become a whirlwind?
How often can an Air Elemental use Whirlwind?
The ability's template includes a frequency
whirlwind (3/day, 10–30 ft. high, 1d6+6 damage, DC 15)
But the bestiary entry for Small Air Elemental doesn't.
whirlwind (DC 12, 10-20 ft.)
If a Small Air Elemental creates a 20' tall whirlwind, what's the size category of the whirlwind?
Creatures one or more size categories smaller than the whirlwind might take damage when caught in the whirlwind […]
Is it the size of the creature in its normal form (Small Air Elemental affects Tiny creatures), or does it go by the height of the whirlwind (≥10' affects Medium creatures, ≥20' affects Large creatures, etc)?