I'd commented to Chris that on my recent Europe trip to UK, Denmark, Germany, Netherlands, I'd seen the same problem (Forbidden access).
I think Chris has some extra blocks (outside of the PHPbb blocks) that may be causing the issue. I've sent him a PM to check on it since he has the cPanel for the site.
It has always been the intent of WXForum.net to include discussions from fellow weather enthusiasts from around the world. We do recommend that all discussions take place in English, but that's the only general expectation.
We'll get the access fixed... thanks for your patience!
Best regards,
Ken