Afternoon Matt,
Well, I grew up in the LA area, went to school up in SLO, worked in Santa Barbara, San Diego, SLO, then moved up to Seattle for a bit over 7 years. I have been living in Arizona now for the last 25 years. I am not a professional photographer, so I really can't address that aspect. Engineering, I can comment on.
In terms of astrophotography, you really can't beat Arizona. As you know - from your website, AZ also has some pretty specular landscapes along with clear skys (and the telescope farms on Kitt Peak and Mt. Graham). Then there is the Arizona Highways magazine (use to be officially banned in Russia). What it does not have is a shoreline, harbors, beaches or an ocean (... yet! - potential beach front property is still available in Quartsite). Washington and Oregon are also wonderful. They have everything that Arizona does not have. Ocean, beaches, shorelines, lighthouses, harbors, mountains, fog, ferries, large bodies of water, fog, overcast, etc.
I remember that the first day sunny day of summer, the entire state of Washington - shuts down since no one goes to work, they don't want to miss possibly the first, last and perhaps the only sunny summer day of the year. Here are some cloud cover links that may also help...