Arctic cold is descending on New England and the snow continues to fly up and down the spine of the Green Mountains. What a start ! More snow is on the way but so is some potential Christmas adversity. It has become a Mad River Glen Christmas tradition dating back 5 years to experience a multi-day thaw and some rain. Once again that threat is very real, but it hasn't happened yet so lets put the reverse jinxy-cat to work.
We can expect 1-2 good bursts of snow on Thursday. The polar vortex will keep the snow showers or snow bands moving very quickly but we can expect a few wind blown inches of accumulation. The blustery winds will obviously make the single digit temperatures feel like it's well below zero. The snow showers will abate by early Friday but readings will begin the day well below zero and will likely fail to break 10.
No epic storm for the weekend but Saturday IS a powder day. We did have the chance to culminate this incredible early season period with a foot or more of powder and we didn't miss this opportunity by much. This large winter storm however will track from Colorado early Saturday toward the eastern Great Lakes and ultimately travel right up the Saint Lawrence River valley on Sunday. It will bring a nice swath of moisture on its speedy trek across the country and will encounter some serious amounts of cold as it does. Clouds will overspread the region Saturday night and snow should begin a few hours before lift operations Saturday. Temperatures will start the day within a few degrees of 10 and we should see some decent snowfall rates during the meaty hours of the ski day Saturday. By lift-closing time, we should see 4-7 inches of snow on the hill with temperatures closer to 25. The latest data suggests that a good chunk of the precipitation will be over by the time precipitation could change to freezing rain or drizzle. The mild layer will expand and intensify however and gradually work its way to the surface allowing readings to climb just above freezing by Sunday morning. We should see a bit of rain around this point before arctic air reasserts itself and sends temperatures plummeting back toward the single numbers Sunday night. The moral of all this is to enjoy Saturday because things will harden up considerably after that.
Aside from some lingering precipitation along the southeast and potentially Mid-Atlantic coastlines, much of the east coast will be dry for several days. Arctic air will only very slowly loosen its grip on the region from Monday to Thursday but we don't expect above freezing temperatures on the mountain until at least Thursday. At this point the models diverge a bit on the handling of the next system. Only stale and limited amounts of cold will be available as a rather generic looking weather system approaches. There are a few hints that this weather producer could get a boost from coastal low pressure area but the impact will be rather minimal otherwise.
There is an evil empire in the Pacific that is responsible for what could be another Christmas or post Christmas meltdown. Both teleconnection indices that we follow will make a decisive turn against us. The jet will tighten in the central and northern Pacific Ocean and the PNA will turn negative allowing the cold to focus its impact on western North America. Ensembles indicate that the peak of the potentially mild weather in this pattern will be in the period between Christmas Day and 12/28. Not every day in this period will feature extreme warmth but it looks more likely that at least two of them will. Within this time frame will likely be a rain producer of some sort. There is some time for alterations in all these expectations but I wouldn't want to mislead anyone about how things look right now. The mild weather should not persist through the New Year and there are signs that it will abate before that.