Snow cover development in October can be a key cog in developing cold airmasses and also developing high arctic blocking patterns in the winter, which help benefit our weather if the NAO is also in a negative alignment. Siberian snow cover -- and a rapid expansion of it westward across Russia -- can help provided that mid latitude patterns and the Pacific cooperate. This latter aspect is a huge wildcard that still is yet to be flushed out.
|Images courtesy of Rutgers Snow Lab.|
Snow pack in itself isn't a full guarantee of a great winter -- October 1998 featured above average snow cover in Eurasia but a cold winter did not materialize in the Eastern US. Other Octobers -- 2009 and 2010, to name two, did follow the norm. Hopefully for snow lovers, snow pack will increase over the duration of October across Eurasia...otherwise, the odds of a snowy winter may take a bit of a setback.