Our computer models are all over the place with the Thanksgiving storm. A highly anomalous pattern featuring large blocks in the upper levels of the atmosphere is making this storm a difficult one to forecast.
Last night’s 00z Euro run sent a fairly intense storm way west, cutting through the Great Lakes, and sending warmth and rain into all of New England late Thursday and into Friday. The run showed freezing rain and sleet at the onset in Vermont but even there temperatures wind up warming well above freezing before the storm ends. This map valid Thanksgiving evening shows the storm moving through Wisconsin! Unless there is a stronger secondary storm that forms near southern New England to lock in the cold this setup is no good for snow in New England. In fact by Friday morning the Euro has temperatures near 60 degrees in New London and the 32 degree isotherm in southern Quebec!
On the other hand the GFS has been consistently taking a weaker and more sheared out storm south of New England producing a much colder and wintry scenario. The 06z GFS produced a decent snowstorm (probably 6″ of so) for the higher elevations of Vermont and New Hampshire with even some snow and sleet in parts of interior Connecticut and Massachusetts (not much accumulation) on Thanksgiving.
It’s most likely the truth will lie somewhere in between the Euro and GFS with snow, sleet, and freezing rain likely across Vermont and maybe northwest Massachusetts with mainly rain in Connecticut after a brief and light wintry mix to start. If the storm is able to hold on to enough cold air in mid levels of the atmosphere a light to moderate snow is possible in the higher elevations of southern Vermont but it’s too early to say anything with much confidence.