Wet snow late Sunday and Sunday night will turn more powdery Monday as temperatures nosedive

Most of the current weekend will be on the cloudier side but temperatures will be rather mild for late December, achieving and exceeding the freezing mark both Saturday and Sunday. The question we all want answered though is whether or not to use that last vacation day of 2013 on Monday (or fake sick). There has been some small modifications in the thinking regarding the storm that is expected to advance up the Atlantic Coast Sunday and spread precipitation into the region Sunday afternoon but we think we have enough information to provide some detailed expectations.

Given the prevailing mild temperatures encompassing the mountain, you would be right to say that temperatures will be in that marginal category Sunday afternoon as precipitation commences. Model cross sections are in fact indicating some above freezing layers in the lower troposphere, and as a result, precipitation may begin as some rain or sleet. Within an hour or so of the precipitation start time, we should begin seeing all snow. Temperatures will hover around the freezing mark through a good part of Sunday night and the snow consistency could be a bit gloppy in low lying areas while closer to powder near the summits. In areas below 1000 feet, precipitation could remain mostly rain or simply a rain/snow mix. The snow should taper to flurries or snow showers Monday morning as the arctic deluge reaches the mountain but a few hours of heavy snow overnight should push snow totals in the 6-12 inch category. As wet as the snow might seem Monday night, plummeting temperatures during the day Monday will alter the consistency of the snow to a dense powdery layer. It will also be quite blustery creating wind chills of near zero as actual temperatures to near 10 by late in the day. 

The arctic cold will prevail through the New Years holiday and into the first full weekend of 2014. Models are not at all conclusive regarding some of the fast moving systems that might be on the weather map during much of this time frame. The American model suggests that a clipper system will rotate into the Ohio Valley around New Years Day and later intensify off the northeast coast into something fairly interesting by Jan 2nd or 3rd. The European Model keeps much of the precipitation from this system well south of the region and by the weekend has a massive coastal system near Cape Hatteras with historic snows in the Virginia Tidewater area. The Canadian model is also on the dry and cold side for interior New England. There is undoubtedly a few things that need to be sorted out. For the mountain, our best  shot at some additional snow comes late New Years eve into New Years day. We do know it will be very cold with temperatures near -10 on a few mornings between Tuesday and Friday and struggling to get above zero during the days. 

In the longer range, we still have the negative AO competing with a retrograting ridge. In summary we will go from two favorable teleconnection indices late next week to just one by around January 8th or so. This leaves us somewhat vulnerable for trouble between the 8th and 10th of the month.