December 10-12, 2023 | NE / Mid-Atlantic Winter Storm

[SquallBall]

2 hours ago, Snowadelphia said:

I've been wanting to make the switch for awhile. Finally did it today. The place was really going off the rails.

i agree... i moved over a short time ago...

happy to see a lot of the old accuweather people here

[Rush]

 

 

This is a trend I can get behind.  (Still will end up getting 0)

Edited December 8, 2023 by Rush

[telejunkie]

Still several duds in there, but a lot of SREF members starting to jump on board. Mean up to 5" at closest station on 15z run.

[telejunkie]

36 minutes ago, RobB said:

For the sake of the White Christmas movie.  Hope Vermont can score 🙂

Thanks Rob...although it may not quite be a pretty scene once the storm departs. But the ski areas will be happy that it isn't a complete wash out event (if we do get the colder scenario we're seeing now)

[TLChip]

12 minutes ago, Rush said:

This is a trend I can get behind.  (Still will end up getting 0)

Expecting 0 and being happy with cold rain, can’t be sad right? 🤣

Edited December 8, 2023 by TLChip

[tcari394]

Don't worry everyone!  I have a dentist appointment 45 minutes away at 8:30am on Monday morning, so we are in for a ton of snow from this one.  No matter how hard I try, I normally have to reschedule my winter cleaning due to a snow storm.

Edited December 8, 2023 by tcari394
spelling

[JDClapper]

Some 15z SREF POPs for CPA, NEPA and SNY.  Changeover general around and after 1am.  But I'm still in the camp it will probably be a tad sooner than modelled or forecast.  May not change the end amounts or results, but timing has tended to be quicker from my observations.

 

 

Edited December 8, 2023 by JDClapper

[JDClapper]

Some 1, 2 and 4" probabilities between 7am Sunday - 7am Monday.  Update was at 10am today.

 

[JDClapper]

Through 7am.. trend past 4 nambino runs

[JDClapper]

Sheesh

 

[JDClapper]

Feeling we'll see mostly generic 1-3, 3-6" forecasts down this way, but there's going to be a stipe that gets pasted with 10"+, that's my hunch.

[MDBlueridge]

Can't happen. 

[telejunkie]

First official NAM-job of the season for me....now definitely won't happen.

[Pghsnow]

RGEM keeps my hopes alive here in WPa

[so_whats_happening]

3 hours ago, TLChip said:

It’s not happening, I shouldn’t even post this long range NAM trend. 

 

I should pull my weather station and pull out the leaves that have my rain gauge clogged, lots of QPF to be measured. 😅

 

 

P.S welcome to the sphere for the newer members! Haven’t been to disco since last year, sad to hear they’re forcing people to sub now. 

Lol maybe if we keep nay saying it we could will it into a snowstorm. I like the tactic go opposite so that the system goes 'oh yea well how bout this!'

[so_whats_happening]

38 minutes ago, JDClapper said:

Sheesh

 

Would be lovely if the system got going just a few hours earlier. Starting to like the idea of at least some snow mixing in even down this way.

[TheRex]

BTV's latest forecast discussion for the event.  Rain to start then switches to snow and then heavy snow.  The trend has been our friend.  The area could see 12"-18" inches in the central and northern Green Mountains.

Quote

SHORT TERM /SUNDAY THROUGH MONDAY/...
As of 356 PM EST Friday...Flood watch for eastern Dacks into
central/northern VT from 21z Sunday to 21z Monday for minor flooding
forecasted by the River Forecast Center on the Otter Creek,
Winooski, Ausable, and Mad Rivers.

Winter storm watch for northern New York into parts of
central/northern VT from 03z Monday to 00z Tues for the potential
for heavy wet snowfall of 5 to 10 inches with localized 12 to 18
inches for the central/northern Green Mtns. Scattered power outages
possible, along with a hazardous Monday morning commute. It should
be noted part of this watch will probably be converted to an
advisory, while other areas are upgraded to a warning.

Latest trends have been for a faster frontal passage on Sunday night
and a slight eastward shift in sfc low pres developing along
boundary late Sunday night into Monday, which has shifted the
heaviest qpf eastward, while moving the cooler air in quicker.

It should be noted, additional shifts/trends are likely and a large
spread continues in our snowfall probability graphics, indicating
the complexity of this event.

The challenging part of the fcst is how quickly the s/w energy
phases and systems deepens, along with advection of cooler thermal
profiles, interacting with deeper moisture. This system has very
rich moisture and extremely strong s/w and jet dynamics, adding to
the complexity.

Water vapor shows a developing and very complex mid/upper lvl trof
acrs the eastern Rockies/High Plains, while potent 25h jet is
rounding the trof base acrs the southern Rockies. This developing
full latitude trof wl advance eastward and be located acrs the MS
Valley by Sunday aftn, with deep southerly flow of abundant moisture
advecting into the Mid Atlantic/NE CONUS. PW values surge to 1.0 to
1.25 ahead of boundary, which is 3 to 4 STD above normal for mid
Dec. As potent s/w energy located over central/northern CO this aftn
rounds the trof base and travels along sharpening thermal gradient
low pres wl quickly deepen acrs the eastern Seaboard on Sunday
Night. Helping enhance rapidly deepening sfc low pres wl be a
favorable dual 25h jet structure with max vertical ascent acrs
southern New England. In addition, 925mb to 700mb circulation
quickly closes off acrs southern/eastern New England by Monday
morning, while sub 985mb low pres continues to deepen acrs the Gulf
of Maine. As low pres deepens 925mb to 850mb flow wl shift to the
northwest, resulting in moderate llvl caa developing on backside of
system. As the thermal gradient tightens, an narrow axis of very
favorable 850 to 700mb fgen forcing develops acrs our
central/eastern cwa, resulting in a period of moderate to heavy
precip late Sunday night into Monday. The dynamical cooling should
help to cool column enough for a switch to heavy wet snow from west
to east acrs our region late Sunday night into Monday. The timing of
phasing and interaction of moisture with cooling thermal profiles,
makes for an extremely challenging snowfall fcst.

Our crnt thinking rain develops acrs our western cwa on Sunday
morning and increases in areal coverage/intensity on Sunday
aftn/evening with localized moderate rainfall likely. As cooler air
develops, rain changes to snow acrs the dacks btwn 03-06z on Monday,
06-09z northern Greens, and 09-12z for northern CPV/central VT zns,
and btwn 12z-15z for eastern/southern VT areas. This is definitely
subject to change as we continue to fine tune the fcst. As colder
air deepens our snow ratios wl be changing throughout the event, but
wl start at 4/6 to 1 but transitioning to 10/12 to 1 on the
backside. Given the heavy wet snowfall and developing backside
winds, scattered power outages are possible, including parts of the
Champlain Valley on Monday. In addition, with snowfall rates
exceeding 1 inch per hour.

For our storm total snowfall we continue to be on the lower side of
the snowfall probability guidance due to uncertainty on
moisture/thermal profiles. For example at BTV our mostly likely
ranges from 2 to 8.5 inches, with our expected amount of 3 inches.
Meanwhile at Stowe our mostly likely range is 6.2 to 13.8 inches
with out expected amount of 10 inches. This provides users with an
idea of potential possibilities and we anticipate the cap to close
as event becomes closer. For the watch we are wording as total snow
accumulations of 5 to 10 inches, with localized 12 to 18 inches
possible across the central and northern Green Mountains of Vermont.
Outside the watch a dusting to 4 inches possible.

Highs on Sunday range from the l/m 40s eastern VT to l/m 50s in
favorable downslope areas with localized wind gusts 30 to 35 mph
possible parts of the northern Dacks/western Slopes. Sunday night
lows range from mid 20s summits to near 40F lower CT River Valley,
with highs remaining steady or falling on Monday.

 

[TheRex]

BTV's expected snowfall map and high end 10% chance of happening map.  There is a big difference at the moment from some places on the maps.

Quote

 

[Mainiac]

Well, at least there are a few hopeful members...

 

But looks to be a rainy mess. Currently have 2"-4" of snow on the ground, but expect that to be power washed away.  I would need the track to shift.

 

 

[MDBlueridge]

NWS getting frisky down here for higher elevations. I guess they didn't see my note about this not happening. 

A strong cold front will move through the area Sunday evening into
Sunday night, leading to an abrupt drop in temperatures from the
50s/60s to the 30s. With the primary upper trough, and
associated differential cyclonic vorticity advection driven
ascent lagging a bit behind the surface cold front, some
anafrontal precipitation is expected. As a result, the
precipitation may change over to snow for a brief time Sunday
night before ending. This will almost certainly occur along and
west of the Allegheny Front, as well as along the Blue Ridge.
Further east, and at lower elevations, there`s a bit more
uncertainty, but many model solutions do show a changeover to
snow for a few hours. However, surface temperatures are at 35 or
36 degrees in valley locations while this occurs. So as of right
now, the expected scenario is for snow accumulations to remain
primarily confined to the west of the Blue Ridge, and at
elevations of 1500 feet or greater. In these locations, a couple
of inches may accumulate by daybreak Monday. At lower
elevations, there may be a changeover to all snow, but it likely
won`t accumulate with surface temperatures expected to stay well
above freezing.

[MaineJay]

This is pure liquid.

 

[MaineJay]

Heavy snow and icing disco.

Quote

...Central Appalachians through the Interior Northeast...

Day 3...

Energy currently centered over the northern Plains is forecast to move farther east and north into the Great Lakes and eastern Canada on Sunday. Meanwhile energy over the western U.S. will dig to the south, contributing to a sharp positively-tilted trough extending from the Great Lakes to the western Gulf Coast early Sunday. Energy moving through the base of the trough is forecast to assume a negative-tilt as it swings across the southeastern U.S. Sunday evening, spurring the rapid development of a surface low tracking north along a sharp cold front, with guidance continuing to show a powerful cyclone tracking across New England on Monday. The deepening low will direct moisture onto the cold side of the front, supporting rain changing to snow beginning Sunday evening across the southern to central Appalachians, before moving north through the interior Northeast Sunday night and Monday. The heaviest amounts are expected to center across northern Upstate New York and northern Vermont where a coupled upper jet and strong low-to-mid level frontogenesis are forecast to support heavy rates on the backside of the low.

The latest WPC guidance is showing moderate to high probabilities for accumulations of 8 inches or more across this area. This is expected to be a fast-moving storm, with the surface low moving quickly into eastern Canada by Monday evening. However, strong northwesterly to westerly flow in the wake of the system will support lake effect and orographic snows, contributing to additional amounts in the lee of the lower Great Lakes and over northern New England late in the period.

 

[TheRex]

18Z GFS moved the axis of the snow further east.

Quote

 

[MaineJay]

Last 5 days worth of GFS runs.

[JDClapper]

Some updated prob's for 1, 2 and 4" of snow, from 7pm Sun-7pm Mon