   Global weather simulator
  I am thinking about making a global weather simulator.  The idea is that based on a land and water mass similar to the earth, I would like to simulate weather patterns for the world.  I am talking at a large scale level.  Basically, I want my weather system to create thunder storms, snow, sleet, hail, etc.  In the future, I would also like add in hurricanes, tornadoes, etc.  I am not looking for accurate simulation per se, just reasonable and realistic.  I plan for the simulator to tell the client what kind of storm is where and what the intensity of that storm is.  The client will be in charge of actually figuring out how to draw the storm.  I am not planning on using the simulator to actually predict what the storm would look like on the client if that makes sense.  Has anyone attempted this before?  If so, what kind of problems did you run into?  What resources did you find helpful?   
  SimEarth did a reasonable job of this.  Also, there's the BUGS site.Basically you want to simulate something like the Hadley cells.  Combined with the twisting of the air currents from the Coriolis effect.  And then model moisture getting sucked into warm low winds from the oceans and turning into clouds in the high cold winds above land.   ;  very cool.  Thanks for the link to the BUGS site.  That looks very promising.   ;  You can also take a look at this project I did two years ago.  It wasn't a weather simulator (never got that far), but it does use the geodesic grid the BUGS site talks about, so you could steal my implementation of the data structure if nothing else.I did some initial thinking about how an atmospheric simulator would work.  What I came up with was to do three separate layers.  The bottom layer for rain clouds at sea level, the middle layer for reasons I forget (something to do with circulation and mountains), and the top layer for jet streams.  If you set the system up correctly you should end up with some nice emergent weather that makes sense.  Like the top jet stream layers just emerge as a natural consequence instead of being something you explicitly set up.The key is to model warm air wanting to go up (it's lighter/less dense) and cold air wanting to go down (heavier/denser).  And of course warm air holding moisture while cold air doesn't.   