First of all, NS would need to subscribe to a weather service. On top
of that, the weather service would need to have updated weather
forecasts for every mountain in the world. Then, the website would need
to be personalized to your very specific area, and refresh periodically
when new updates came in. It's just too difficult. BUT, if you'd like
to constantly know the forecast for a specific area, check out the firefox
extension Forecastfox. It displays the current weather at the bottom of your browser.