Global/Trigger Weather..

Does Global map weather set in preferences override and trigger based weather? Cause my global map weather is set to light snowfall, but some regions I want it to have heavy snowfall, but it doesn't seemt to be working.

Global weather doesnt overide but it will stack with the triggered created weather effects, or at least I think.

edit: Ehh my bad I forgot I think snow will not work cause it is same effect

If you want different regions with different weather you don't need triggers. Just make the region and under options in the region, you can set any kind of weather you want.

I think you must first use trigger action "Enable Weather Effects"

Nah, you dont have to, Enable is there if you disable them.
Weather effects are enabled at the start.
If a region has a effect, or there is a Triggered effect, they will still appear.
Without Enabling them

What about two regions that overlap with one another?

It would only take you 30 seconds to test it .
Anyway, they overlap and both effects are visual