Mountain weather is notoriously dynamic and regional weather trends can be dramatically altered by local terrain effects. Slight shifts in wind direction can, quite literally, mean the difference between a day of sunshine and 30cm of snow in a whiteout.
Weather forecasts are more accurate in stable (generally high pressure) conditions, whilst the low pressure and un-settled conditions that bring us what we want (snow) are, by their very nature, much more dynamic and difficult to accurately predict. As a rule of thumb, mountain weather forecasts further out than 48-72 hours should only be taken as an indication.
Athough forecast models improve with every year, it is just not possible to accurately predict quantities of fresh snow more than a few days in advance.
We update our snow reports and forecasts several times each day, and you can always find the latest information on the J2Ski Snow Pages at https://www.j2ski.com/snow_forecast/