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Iniciado por http://www.weather.com/services/xmloap.html Weather XML Data Feed
Now you can include weather from The Weather Channel in your own application by signing up for access to our XML data feed. We'll enable you to search for a location and to integrate current conditions and the forecast for today and tomorrow in your application - for FREE!
Te está indicando que para poder ver el XML, tienes que registrarte y que es gratis. Me imagino que después que te registres te darán la documentación más el XML.