The Met Office now have a much improved Mountain specific forecast. Detailed forecasts include a break down of elevation to show temperature, wind, gusts and wind chill.
This is the traditional mountain weather forecasting site. You'll often find this forecast printed in cafe's, hostels, tourist information so it's worth becoming familiar with the format.
We also regularly use a weather app with a rain radar on it. This is great for extremely accurate local rainfall forecasting. There are a number of apps available for Android and iPhone - Home and Dry, Rain Today.
The SAIS publish daily reports of observed and forecast, avalanche, snow, and mountain conditions for the 5 most popular mountain areas of Scotland. They provide a daily avalanche hazard report which will be displayed in cafe's, hostels, tourist information, etc. So it's worth becoming familiar with the format and how to understand the content.
The latest tool for winter adventurers is a handy app with a host of features to help you stay safe in the mountains. Slope aspect and angle tools, avalanche hazard reports, snow stability observations.
Each winter, usually from December to March, Fell top assessors walk up Helvellyn. They check conditions, take photos and supply a report to add to the Met Office weather forecast that appears 365 days a year .