I mean are they wrong through (at least with December)? We've seen time and time again that when a SER establishes itself it takes ~3 weeks to undo the damage and have a winter weather chance again.
I've seen a couple of those and don't know why. We haven't really had any blowtorches recently and the last couple weeks had 2-3 mornings that were below freezing.
Actually their snow came from a different mechanism than what causes our big snows. I actually asked PSU about it when it happened and he said it actually could be possible for the Gulf Coast to score the way they did while at the same time we permanently lose big snows. Now he does not believe we've reached the point where the once a decade big snow storm is a thing of the past but snowfall is still in an overall decline due to a loss of the smaller marginal events.