Here are some of our favorite weather sites for Bariloche, Cerro Catedral, and Argentina.  The weather in Patagonia is less predictable than other places in the world - which is why we list various sites.  The first two links are all that most enthusiasts really need.

snow-forecast : free 6-day weather service for 3 different different altitudes on the ski slopes at Cerro Catedral.

wind guru - week forcasts for wind and temperature.  Great for windsurfers and kitesurfers!

Alta Patagonia:  Current on-slope conditions and lift info, in Spanish

Here are some more if you need more information: 

Metvuw: New Zealand Weather Service. Forecasts for every six hours up to 72 hours 

Accuweather : Excellent for the city and the airport, with 15-day forecasts and good satellite images

weather.com : general Bariloche from a popular weather site, with great satellite images

        - live satellite animation  

Nasa : Nasa World Satellite

sunrockice : Collection of Weather Sites from New Zealand
      (check out South Polar satellite shots)

bom : Australia Weather Service, South Pacific MSL analysis

wisc.edu :  World Satellite Composites from the University of Wisconsin 

Centro Atomico Bariloche :  Historic weather data from Bariloche's Atomic Research Center  (in Spanish)

weatherbug.com : another general weather site, with full South America satellite