Weather

i'm making a snowy map right now, and i want the whole map to have the weather effect of the northrend blizzard , but then after around five minutes or so, it changes to falling snow (the heavier one), then after five minutes it changes to the lighter falling snow, then repeat.. (basically i want it to last forever until the game ends)

is it impossible?

This is really easy.

make three triggers.

Events
Map initalization
Actions
Create weather northrend snow at playable map area
Activate last created weather effect
wait 300 seconds
Run trigger 2

Actions
destroy last created weather effect
Create falling snow at playble map area
activate last effect
wait 300 seconds
run trigger 3

Actions
destroy last created weather effect
Create light snow at playble map area
activate last effect
wait 300 seconds
run trigger 1(ignoring conditions)

Or use object editor