Scenery with Thermals

[Gringo6]

Lately I've been flying sailplanes and enjoy it very much. One of the first things I added was scenery that added thermals to several selected airports around the world.

I would like to add thermals to some other airports that I fly out of that haven't been made yet.

So my question is: how do you make scenery to add thermals to existing airports?

It doesn't seem to matter which version of F/S you use since the same .bgl file will work in FS8, FS9 and FSX.

Is it possible that there is a tutorial out there that covers this?

Thanks,

Billa (aka Gringo6)