Heavy snowfall and rainfall are broken
Wind speed set to 20 for both snow and rain weather, snow ripples are enabled, OpenMW:
For some reason the raindrops/snow ripples don't show up on water and the particles act weird, Wind direction is still correct though and NPCs block with their hands as expected.
Morrowind for reference:
Snowfall, heavy: heavy_snowfall_mw
Vanilla value: slow_snowfall_mw
Rainfall, heavy: heavy_rainfall_mw
Vanilla value: slow_rainfall_mw