I found a solution for the rain sounds. Will post the script here later that needs to be used in your missions if you want to have snowfall on without the annoying impact sounds playing inside vehicles.

-*Edit posted in description

Snow roads turn brown at short distances. Will be fixed

-* Fix ready

Map humidity will be adjusted to prevent dust on dirt roads.

Theres a bug due to low cell size that causes zeus artillery support module to crash

Try to avoid avoid use of Zeus and use other means of calling artillery, I/e AI group member placed in artillery piece outside map to avoid this issue.