Thanksgiving

[JD]

Looks like another system end of this week. We gonna start where we left off with the holiday storm cycles?

[ajl50]

that would be nice...
I'll take copious holiday rain here in philly if it means snow for the north country.

[danny p]

has anyone heard any good news about the precip for thanksgiving? any northern ski areas gonna get the white stuff instead of the wet stuff? any predicted rain/snow lines predicted yet? I haven't seen anything but ncp so far...

[ALLSKIING]

I think its all ncp.....just pray its not much.

[BeanoNYC]

Originally Posted by ajl50

that would be nice...
I'll take copious holiday rain here in philly if it means snow for the north country.

good man.

[andyzee]

NCP seems to be the trend for Thanksgiving. Normally rain thanksgiving day followed by freezing temp overnight and ice. Play it safe and stay home, I'll be sure to take pics and post to let you see what you missed.

[loafer89]

It looks like it will stay snow for exteme Northern Vermont, New Hampshire and Maine for most of the time with a bit of freezing rain and sleet mixed in.

[Bob R]

I won't take pictures and I'll be out. Look us up Loafer89.

[awf170]

Any ideas powderfreak and others? NECN is saying that is going to close, but northern NE should stay mostly snow. Any opinions on it?

Man, another foot in the northern mountains and basically everything would be skiable. One can dream...


Edit: Wow, I missed JD thread. I suck.

[powderfreak]

Here's a time-line for the next event...

Wednesday Afternoon and Evening: Mixed precipitation breaks out with snow/sleet/freezing rain all equally possible...transitioning to all rain except pockets of freezing rain across far northern NY and northern VT east of the Green Mtn Spine. Scattered rain showers are all thats expected down south towards Rutland.

Wednesday Night: Showery precipitation becomes more stratiform in nature. Heaviest in the north. Mixed precipitation could continue near Jay Peak. Temps hold steady in the mid 30's to lower 40's area wide.

Thursday and Thurs Night: Falling temperatures will bring a quick changeover to the western and northern Adirondacks and maybe up towards Jay Peak during the morning hours. This changeover line will slowly work its way southeast. Snow should reach BTV and points ESE later Thurs PM within a few hours of darkness. A light snow accumulation of 1-4" is likely in the Adirondacks, central and northern Green Mountains, and northern White Mountains by Friday morning. Whiteface and Jay Peak are the wildcards right now with the rain/snow line inching closer during time of heaviest precipitation. They could come out with 4"+ by Friday morning.

Friday: Much colder and breezy conditions will be the rule on Friday...with upslope light snow occurring across mainly the west slopes of the Green Mountains and in prone areas of northern NH (Bretton Woods and Cannon mostly). A dry air punch sometime later Friday will cause areas of snow to decrease. I'm thinking total snowfall between 2pm Thurs and 2pm Friday will be 4-8" across the northern spine and northern Adirondacks, 3-6" across the central spine and northern NH, and a trace to 3" across the rest of VT...though not much will happen south of a Glens Falls-Rutland-Lebanon line. It will get pretty cold Friday night as high pressure builds in.

Discussion:

I've been holding off on making a distinct call for this upcoming system because the NAM and GFS were at odds...with the NAM being significantly colder and staying mostly snow from BTV northward. Alas, the 18z and 00z runs of the NAM finally switched gears and trended significantly towards the GFS. The European is also in line with the GFS so will follow a solution heavily weighted towards those models, at least in the larger scheme of things, but as always tweak this to my local knowledge of how wx interacts with the north country terrain.

A strong area of baroclinicity is developing across northern NY and northern New England...caused by an incredibly temperature gradient at the 850mb level. To give an example, 2pm Thursday has a 5,000ft temp of +10C at ALB and -7C at BUF! Strong thickness packing along the temp gradient in upstate NY through northern New England will be the focus of heavier precipitation. Strong mid-level WAA can be seen on the thickness plots with as 850-700mb thicknesses (measure of the depth of cold air) are too high to support snow. Boundary layer temps will be in the 30's and low 40's so we shouldn't have a freezing rain problem except maybe in low elevation areas along the border as the High-Res NAM is indicating some spot 32F areas in the NE Kingdom over into northern NH.

Thursday will be a tricky day and with rapidly dropping temps, we should see some stronger wind gusts during the time of transition...some wind hold may be a problem Thursday afternoon. I'm noticing a subtle trend which we've seen in past storms near this time of year, and its the strength of the low level cold air that may try to under-cut the frontal boundary. Valley locations in northern NY and west of the Green Mtn spine (CPV) might go over to a period of freezing rain/sleet before the change to snow. Low level cold air can funnel down the St. Lawrence valley and Champlain Valley before it hits a 4K foot wall and stops. Just like the cold gets locked in east of the spine, so does warm air so may take longer to reach the surface east of immediate spine. This is a minor but interesting feature that could cause an ice layer before the change to snow.

Overall, precipitation exits pretty quickly after the cold air arrives but we should see a period of moderate snow and rapidly falling temperatures Thursday evening. Take note if you are traveling...a flash freeze is very possible.

Will continue to monitor the backlash snows but expecting light to moderate amounts across most of ski country with the larger valleys seeing a dusting to a couple inches.

-Scott