I have messed with this a bit more for different effects, Here is another for you to mess with.
if never() and Past(90) then
overcast(70,10)
endif
if never() and Past(120) then
rain(100,30)
overcast(100,10)
endif
if never() and Past(130) then
movefog(200,40)
endif
if never() and Past(360) then
rain(0,20)
endif
if never() and Past(370) then
movefog(275,60)
overcast(0,10)
endif
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