It's all about the "Polar Vortex"

Very cold weather has enveloped the state and particularly the high country where temperatures even during the day have remained below zero Tuesday. This general theme should continue through the duration of the week and aside for a few insignificant flurries, it will remain dry. We had hoped a clipper Thursday could provide a little refreshening but the Polar Jet obliterates this thing before any constructive interaction can occur with the Atlantic Ocean. On Friday we should see temperatures inch above the zero line and with light winds and good visibility, it should almost feel nice.

Our next very good chance of snow comes Saturday from another clipper. These types of systems often lack substantial amounts of moisture but this one is a bit more dynamic and will mark the advance of a reenforcing shot of chill for Sunday. Light snow should begin pretty early in the day and continue through the evening. I don't expect we see a major accumulation from this but 2-4 inches is a good preliminary guess. Saturday's temps should also moderate, reaching the low 20's as the snow is flying. Flurries will continue through a good part of Sunday as well but we are back in the deep freeze with daytime temperatures between zero and 10.

The media has fallen in love with the "polar vortex" phrase and why not. It's an easy hashtag on twitter and a charismatic headline for cable news. This particular "vortex" of cold in the jet stream will position itself south of the Hudson Bay and impulses rotating around this feature will continuously bring big shots of extreme cold to New England over the next week. The last of these impulses and potentially the biggest shot of cold arrives early next week. I think we can be pretty sure that temperatures will nosedive toward the -20 degree range Tuesday or maybe Wednesday morning. The question relates to yet another clipper associated with this last PV impulse and whether or not it can deliver some additional snows to the region Monday. At this point it seems reasonable to expect at least a little.

Beyond the middle part of the week, it still appears as if the jet stream will split across western North America. A significant and potentially fruitful development. We should see a big increase in storminess across the country and there are now indications of that on various models late next week into early February. At the same time, we should see temperatures moderate; in fact, readings could actually creep above average by early February. In the end, there should be enough competing forces in the overall pattern to make this a potentially very good period for Vermont. The split flow across the west and just enough cold air positioned across Canada could be the ticket to some big snows. The first of these may or may not occur between January 30 and Feb 1 with additional chances thereafter.