I wouldn't get my hopes up there, Dan Greenawalt has stated that in his opinion, weather like rain is not a high priority for a racing simulator, since people don't race in the rain generally.
SCCA?
IMSA?
NASA?
Sure it doesn't happen all the time, but just like damage it's a big part of racing. In his defense he was probably just deflecting the question because FM2 doesn't have weather. At least that is what I hope.