If you want snow, that is...
We have had some hints of a coastal storm for over a week now on weather models. That, in weather world, is pretty rare to have a storm stay on track for over 7 days. It might have even been longer than that, but really, past 8 days out, I don't take much to heart with forecast models... anyway, I digress.
Let's talk about this next storm for Wednesday night-Thursday! It's a Nor'easter- and a decent one, too! As of Monday night (Christmas Eve) the energy of this storm system brought snow to parts of the intermountain west, through Colorado, Utah (click for timelapse from Bountiful, UT), and the mountains of northern New Mexico! That energy will ride the jet stream, swooping south through the Gulf coast states by Christmas Day. This will, unfortunately for Louisiana and Alabama, mean severe thunderstorms and the risk of tornadoes on Christmas Day (click for info from SPC). Once that storm shifts out toward the mid Atlantic states on Wednesday, it will re-focus it's energy to the coastline of around the Del Marva, then move toward about Cape Cod on Thursday morning. This is pretty much a perfect track for our area to get decent snowfall. And indeed, that's what I expect.
As of Monday night (Christmas Eve), models had very good consistency in the track and intensity of this storm by Thursday. A spit out of total liquid precipitation is on the order of .75-1.25" for our region. A loose translation of snowfall is to use a 12:1 ratio (ie: 1" of liquid = 12" snowfall). Given that, we would be in for a widespread 9-15" of snow through Thursday. As of Christmas night, the going forecast is about that...I've generalized 8-14" of snow for most areas- Now we must dig into more detail! The influence of local terrain will play a role, as it often does here in our bumpy region. The influence of mountains will cause areas of locally higher and also locally lower snow amounts. First...let's talk where snow totals will be higher. We'll be looking to 2 areas for locally higher totals- along the spine of the central and southern Green mountains and along the eastern facing slopes of the mountains there may see some enhancement as upslope flow enhances snowfall there. The other region will be in the Adirondacks where slightly colder temps will increase that snow ratio (fluff factor), perhaps to 15:1 or so. Because of this, totals may be slightly higher, along the lines of 10-18". Now on the lower end, just like upslope conditions will increase the snow amounts for some, downsloping will keep totals slightly lower along the leeward side of our mountains. Particularly just to the west of the White Mountain region in NH, slightly lower totals of 4-9" are currently in my forecast. Feeling the low level moisture flow will be blocked by the 3000-6000' mountain region. So parts of Caledonia and Essex county in Vermont, as well as northwestern Grafton county will be "shadowed" from some snowfall.
For a few given locations, here's an estimated snowfall forecast as of Monday night.
Burlington: 11" (thanks to some quick stats from the Burlington NWS staff, the last 6"+ snowfall in Burlington was March 7, 2011!)
St Johnsbury: 7"
Saranac Lake, NY: 15"
Montreal, QC: 12" (~30 cm)
Lebanon, NH: 9"