Where would you expect snow or rain to fall on a mountain?

on the down wind side

on the leeward side

on the windward side

it is just as likely to have snowfall on either side of a mountain.

The windward side

There are two sides of the mountain i.e windward side and leeward side. The windward side is that side of a mountain subject to the prevailing wind, and is thus the wetter side. When air reaches the mountain, it rises because the mountains are in the way. As the air rises, it cools, and because cool air can carry less moisture than warm air, there is usually snow or rainfall. So windward side cause rain or snow.