That reminds me, I might as well make sure everyone understands the effects the wind might have. Basically, at 20 mph or less, there is no game effect. At higher wind speeds, missile weapons become increasingly difficult to use (impossible at 51+ mph), creatures begin to be knocked down or blown away (Fort save based), and dust of disappearance is ripped away.
Wind can also penalize or entirely prevent Listen checks, kick up waves, hit you with damaging sand, and even reduce visibility if there is debris.
Strong winds can be used to very good effect in adventures, making otherwise boring fights very exciting, as the PCs scramble to stay in place or find a shield against the wind to allow a few shots with an arrow.
A note on timing: the game is going slower (in rounds) and faster (in agression) than I had originally thought, so 5-10 rounds between changes is likely too slow. As long as it doesn't bother anyone, I'll be changing the timing from 1d6+4 to 1d4+2 (3-6 rounds). Regardless, this wind will not be at full strength until round 5, per my original plans.