Hello Geoff!!! Nice to see you here!!

Regarding climates, you well know how hard it is to calculate what you want. I remember reading a paper about the winds of Argentina (the pampero, the sudestada and another one I can't remember its name...), which gave some figures about speed and humidity change while crossing the Andes. I'll have to go to the library to check it out, though...

However, it would be extremely hard to code...

Idea: How about using a FEA software, like abaqus (which is GNU iirc) or CFD like OpenFOAM (Which is GPL, but I have to say I haven't used -not my field...), although I'm not sure about the last one... I just heard about it from my buddies at uni.

relevant links:

CFD

FEA


Of course, we end up where we always do: yet another thing to learn to aid our secret vice of conworlding