Weather forecasting remains at a relatively "black art" in spite of the best efforts of modern technology. The SkiTools CD-ROM contains a comprehensive section devoted to explaining how to predict the weather in the mountains - based on general large scale weather patterns and local effects. Understanding how to recognise clouds and other signs of local weather development is important for safety and pleasure in the mountains. With this in mind, realising that local weather is subject to greater large scale weather patterns, my advice is to look at the Met. Office weather reports - it is there that probably the best internet weather reporting is to be found. Local weather reports can be useful - but it is best to learn how to interpret the development of mountain weather for yourself - as frequently the local reports are caught out. Weather is subject to the effect of "sensitivity to initial conditions". This means that a very small inaccuracy in measurements is rapidly amplified so that predictions are liable to be wrong after a short period of time "known as the butterfly effect". This is a problem that is certainly insurmountable by technology in the forseeable future - so it is best to learn a bit about how to interpret the development for yourself on the mountain.

24 hour satellite animation
3 day pressure animation
Cloud/Pressure composite
Infrared Satellite Earth
Infrared Satellite Europe
Visible Satellite Europe

Met Office (Great general weather forecasting)
Satellite imaging and animation - not much "local" information.

Meteo France (Alpine, European and World weather - in French)
A great deal of useful information here - including a dictionary of meterological terms with photographs. This is even usefull if you don't understand French as the terminology is the same as for English.

USA Today (American and World wide weather)
Practical and detailed information without any technical understanding required. A considerable amount of interesting and informative background information is available.