I agree with Brian the humidity alone doesn't create good seeing conditions. Desert observatories on mountains in Chile (and southern Arizona, for that matter) have great seeing independent of humidity. But maybe Derrick is onto something regarding air mixing. One thing is certain. If you're observing on the desert or Valley floor on a calm night during our other nine months of dry weather and a breeze comes along, you can bet the seeing will degrade quickly. I have recently observed on two breezy Monsoon nights that have been steady. Were these conditions both rare exceptions or the rule? The only way to find out is to set up the scope and look, which was the reason for my original post. By the way, what remains of the South Equatorial Belt of Jupiter is about as interesting these days as I have ever seen it. Tom -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.