I'd think that the big satellite picture is going to get a bit nasty during chase season with people trying to load the forums on their mobile phones or wireless internet connections. Could we just have a link to it instead maybe?
That being said, there's plugins for certain types of mobile phone browsers for most cms/forum software these days.
Does this site have any subdomains available? You can set m.theaustralianweatherforum.com to run a low bandwith, mobile friendly phpbb theme which will run the same content.