Online campaign: local geo questions

[Magyar Khan]

1) is the baltic sea frozen in winter or is it "sailable"?

2) how hard is it for an army to move thru mountainous regions in winter?

3) do regions with an arid climate undergo regulary snowing in winter?

[Postino]

1) not a clue
2) very difficult, but it would vary with the paticular mountains you are trying to pass and the actual area you are passing through them. here is some more work for you: a local terrain difficulty rating. this is effected by season. this effects march rate, moral, mabey casualities, supply availability, etc. ouch, you can ignore that suggestion if you like.
3) depends on how much moisture they get on a regular basis. from west to east, sea, tundra, mountains, tundra. the first tundra would receive lots of snow, but the second tundra would just be dry and butt cold. again, geography and more research for you.