As an aside, studies suggest that increased atmospheric moisture content as a result of AGW should actually enhance upward EP flux in the subtropics and polar regions, particularly in the winter.... That's the posited physical mechanism for disturbing the PV (or at least it used it to be). I haven't followed the literature closely enough to see how well the link between snow cover (extent or advance) and +EP flux anomailes has been established over the years... we had some anecdotal evidence of correlation but not what I'd call conclusive, and the physical mechanism explanation could have used some work as well. It also sucked when the Berlin site went down that you used to be able to monitor this stuff with.
At any rate, I can't help myself and still check wave 2 plots pretty often through December into Jan, but I've definitely got the feeling that the whole thing is a secondary signal at best as I've watched winters come and go.