[Solved] Weather-change (in a small area)

Hiya, how do I change the weather on the map, but only in a small area? Like I make a region, and a sandstorm comes every 5 minutes for 10 seconds at the region, is this possible or does it only work on the whole map?

Events

Time - Every 300.00 seconds of game time

Actions

Environment - Create at Rect 000 <gen> the weather effect Ashenvale Rain (Heavy)

If you have several weathereffects you'll need local variable (or global variable with array) to delete it.

Set w = (Last created weather effect)
Wait 10.00 seconds
Environment - Remove w
set w=null

Wow thanks! Much much appreciated :)