Did I Write the Sunday Storm Off Too Quickly?

Yesterday I blogged about all of our models yanking the Sunday/Monday storm far inland and virtually guaranteeing a rain storm. With no help from the -NAO and no semblance of a high pressure to the north getting things to change enough for snow was going to be hard to do.

Some of our models, however, are beginning to shift to a more interesting scenario, particularly for the Berkshires and Green Mountains. It’s possible that Connecticut could cash in too if things break just right.  It’s still going to be tough.

Here’s the 12z ECMWF forecast from Tuesday. This is about as awful of a snow setup as you can get. Rain, rain, rain!

Today’s 12z GFS along with the 12z UKMet and the 12z GFS ensembles are much further east. Almost shockingly so. Though this is still a rain event for almost all of New England (some snow at the front and back end in Vermont) it’s pretty close to being a decent snowstorm. The reason is that the Pacific energy responsible for the storm remains separate from a strong jet stream disturbance in southern Canada. Instead of joining forces and phasing over Kentucky and Indiana (forcing the storm way west) the systems remain apart until near the Mid Atlantic coast. At face value this solution would produce a blizzard from central Pennsylvania north through most of upstate New York.

It still appears that rain is most likely from this storm in Connecticut. That said, this storm may still have a few surprises left for us. Stay tuned!

Snow for the Mountains, Cold Elsewhere

A large low pressure system is part of a major block in the northern Hemisphere that extends from the northeast US through western Europe.  A series of storms will develop around this upper level low but will miss southern New England. Downeast Maine and southern Quebec will be hit with snow over the coming days from these storms and a persistent northwest wind along with waves of moisture and lift will be sufficient for a major upslope snow event in the Green Mountains of Vermont.

Though the bulk of the snow will be across northern Vermont, central and southern areas above 2500 feet will see some flying on and off from Saturday through Tuesday. Generally 2″-4″ is expected for most elevated areas though the higher elevations and areas that tend to get more upslope snow (like Killington) could pick up 4″-8″+ of snow in this long duration event.

For areas not getting snow (like most of southern New England) an unseasonably cold and cloudy airmass will settle in. Periods of flurries are possible but they won’t amount to much. Temperatures will stay in the 30s for many areas though the valley locations and shoreline will be nearly 40. Temperatures will slowly drop through the middle of next week where 30s will be the rule everywhere for daytime highs.

Our next storm threat appears to be in the 12/13-12/14 period as the block relaxes some and the storm track energizes and changes. This could turn into a winter storm for most of us… stay tuned!

Some Freshies Tomorrow Midday?

Behind the low pressure that brought rain, freezing rain, and sleet to most of northern New England a much colder air mass has moved in. It’s plenty cold (and dry enough) to fire up the snow guns tonight and Mother Nature may have some tricks up her sleeve tomorrow.

Here’s the 18z GFS forecast of 500mb heights and vorticity valid at 1 p.m. Saturday. You can see an impressive vort max sliding through Vermont and New Hampshire. This will provide “lift” in the atmosphere and when coupled with a strong westerly wind upsloping over the Green Mountains I expect 1″-3″ of snow at the higher elevations, particularly for Killington on north. Jay Peak and Stowe could pick up 3″-5″ near the summit. It’s possible places like Mount Snow and Stratton get a quick inch or two if the atmosphere is able the moisten up enough.

It’s been a disappointing start to the winter up north but this is better than nothing!

Where’s the Snow?

Not here! Skiers have been waiting for a burst of snow but unfortunately the cold pattern we’ve just entered will not produce.

Tonight, freezing rain and sleet will muck up the ski slopes in Vermont, but thankfully there will be little melting with temperatures in the low 30s. I am expecting travel problems Friday morning especially on the east slopes of the Green Mountains away from the Connecticut River Valley where subfreezing cold will stay longest. On the left is a temperature forecast for 7 a.m. Friday morning from the 12z NAM.  You can see the 32 degree isotherm straddling the spine of the Greens down to the Massachusetts border with the coldest weather on the east slopes and especially across New Hampshire. Freezing rain is likely for a period of time early Friday across a large chunk of northern New England.

Beyond Friday I’m expecting a solid 48-72 hours of snowmaking weather in the higher elevations of southern and central Vermont. Daytime highs will stay below freezing about 3000 feet with overnight lows in the teen. Very low dew points and relatively light winds will make conditions good for the snow guns.

Early next week looks good with fair weather, light winds, cold nights and seasonable days. Rain may enter the picture on Thursday but we’ll deal with that when it arrives. I’m still hopefully we can squeeze out a snow event sometime in the first 10 days of December.

Big Thanksgiving Questions

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.