When snow falls in September and October, people get excited thinking of powder days ahead. Some even point to the early-season snow as a sign that the upcoming winter will be blessed with tons of powder.
But can we make this claim? Does early snow predict a great (or lousy) season?
In one word, "no". Early season snow (unfortunately) says nothing about what the rest of the season will hold.
For example, here's a bunch of data from a SNOTEL site in the Never Summer mountain range of Colorado (on the western side of Rocky Mountain National Park).
The bottom of the chart shows the months of the snow season, and the vertical shows the amount of snow on the ground.
The red line is the current snow measurement (October 14, 2012), and each dark line shows how the amount of snow that fell in past seasons. The darkest lines are those seasons that also had early snow like this year (the station recorded about 6-12 inches of snow on October 12-13, 2012).
Notice though that some of the darkest lines are great snow years (they go up very high showing lots of snow) and others are lower snow years (they stay lower on the chart).
This means that some years with early snow turned out great, and other years didn't turn out so well.
This all means that early-season snow is a welcome sight, but it's not a good forecasting tool.