Remember, Mt. Wilson and Palomar have some of the best seeing in the world. (Well, seeing, not light pollution!). But a mere five miles east or north of them the seeing is destroyed by the nice stratified ocean air falling into the desert. And that desert is where many of us are suggesting you head. So, while you may not like your seeing, be careful with that which you travelled eight hours to get to!!!
I don't think you even have to go five miles. Seeing is VERY local and the Palomar Observatory Camp Ground seems to have pretty terrible seeing even though it is only about 1.2 miles from the observatory. The problem, I think, with the Observatory Camp Ground is that it sits near to a narrow downslope from the surrounding higher elevations, so there is a funneled current of air that runs down that slope and that pretty much ruins the seeing conditions.
Local conditions like this are one reason why seeing predictions are often wrong. If you could observe from a balloon that was suspended 1000 feet above any of the surrounding terrain or buildings then you could probably depend upon the seeing prediction sites a lot more. As it is, they probably represent not much more than a guess at what could be the BEST that you may get if you happen to live in a good location (but move one mile from that "good" location and things could change significantly and always, I suspect, for the worse). However, most of the prediction sites seem to ignore even fairly large and important weather events like the Santa Ana wind conditions that we get fairly often here in southern California. I've yet to see a Santa Ana condition that produced good seeing and yet the prediction sites often show good seeing on those nights.
All that said, the ocean is by far the biggest influence in terms of both seeing and cloud cover where I live and that's another thing that these weather prediction sites often misrepresent. I live inland about six miles from the ocean and you can pretty much depend that from spring until the fall that the vast majority of the nights will be 100% overcast, even though the weather sites often say otherwise. Unfortunately, many of our clear nights happen during Santa Ana wind conditions which blow the low clouds and fog out to sea but with pretty severe consequences for the seeing (as well as producing our disastrous fires, which admittedly are a much more serious issue).
Edited by james7ca, 17 November 2018 - 04:31 PM.