I've just finished Stronghold v.3, a T2 FM by JohnEric, and I was very impressed by its use of snow and fog. In this one, Garrett has a winter retreat in the mountains. The atmosphere in and around his retreat is superb, and unlike any other Thief mission I've played, original or fan-designed.
Now, the mission was good overall but a little uneven. But this mission, along with belboz' Raid on Washout Central, left me wishing that FM designers would use weather and fog more. Aside from Stronghold and Washout, are there any other FM's that use weather in an interesting way? (I'm assuming they would have to be T2 missions.)