You could do this now by setting up an airport group in your mobile contacts apps with their cell phone numbers. Once you have done it on one cell phone, you can share the group with others as a vcard. Since the FBO usually has cell phone numbers for all the aircraft based at an airport, you should be able to work with them to set up an alert text group.
Setting up a central website and database to do this involves a lot of programming and maintenance even for AOPA. I did it as a limited concept project on my personal web site using PHP and MySQL and concluded that it's much easier to do with existing technology using contact groups.
@Robert Fogle - I live in Montgomery County Maryland, and the county has a special alert text message system for weather and traffic. You may be able to find something similar in your state or county. I also believe that Weather.gov has some type of notification system, but I do not know if you can sign-up for a specific location.