But that's so much simpler than double encoded, ill-formed RDF in a SOAP wrapper. You can tell it's simpler because it doesn't have a namespace. You should write a program that takes their output, encodes it again, and puts it in an OPML attribute. They don't have namespaces either, so it's a perfect match.
Seriously though, it's just a matter of time before someone writes an ultra-liberal weather parser. And then the dream of interoperability of weather data at the purely syntactic level will be utterly shattered. I'd volunteer to shatter it, but I'm a little busy these days.