Clouds will play a bigger part in the radar changes I am planning. I have posted the full plan in the "Idea to alternative to replace AWACS radar" thread.
In short, being near an enemy will no longer put him on your side's map. Someone on your side has to actually see him, and that can't happen if either of you is inside a cloud. So being in a cloud will hide you from the seen contacts of the whole enemy side, not just from the pilot chasing you. Radar contacts are separate, so radar can still show you.
HiTech