November 21-23, 2023 | NE Winter Storm Potential

[MaineJay]

Last 3 runs of the GFS show how important at least partial phasing is. It lost it with the overnight 0z, 6z was generally the same but a degree or two cooler in spots. Not saying it can't go back to more phase, but in a general sense, odds are always in the favor of the unphased solution looking beyond 100 hours.

[MaineJay]

GEFS still look like the more ambitious camp, still a lotta spread. If the ECMWF bias of holding energy back to the SW holds true, I wouldn't argue with leaning that way, say 60/40 GEFS/EPS. 

[MaineJay]

Yikes, the NAM is toasty, long range though and all.

[1816]

Kind of off topic for this storm but it feels to me like the models have been getting worse the last few winters. More wild swings and taking to the last hour to get things figured out. Goes for all of them. 

Who knows what factors are causing this but I would guess the atmosphere being so different from the historical norms that the models use has a lot to do with it. My seasonal prediction for this winter is that this model struggle is going to be worse than ever. We may be able to get ideas of stuff from range but specifics are going to be hard to come by.  May be more useful to pay attention to the organic forecasts bsr etc than the models. 

[MaineJay]

On 11/14/2023 at 5:14 AM, MaineJay said:

EPS suggests a bit of a cutter, but a chance for this to redevelop at the coast.

East Asia more or less agrees.  Departing high pressure may not be able to force this to the coast.  Long way to go, but this may be a storm for our Midwest and OHV friends.

 

11 minutes ago, 1816 said:

Kind of off topic for this storm but it feels to me like the models have been getting worse the last few winters. More wild swings and taking to the last hour to get things figured out. Goes for all of them. 

Who knows what factors are causing this but I would guess the atmosphere being so different from the historical norms that the models use has a lot to do with it. My seasonal prediction for this winter is that this model struggle is going to be worse than ever. We may be able to get ideas of stuff from range but specifics are going to be hard to come by.  May be more useful to pay attention to the organic forecasts bsr etc than the models. 

Organic type forecasting seemed to be suggesting a deeper trof moving through the mid Mississippi valley/OHV. At the time, the models were showing a piece of polar jet crashing down. So there was some agreement there, so they kinda failed equally.

   Certain setups are going to pose problems, I don't think the machine learning did much, if any, better 

 We've moved through a couple rough patches for the models lately, kinda feel like it's the attempts to phase storms by the models.  Generally makes for the biggest misses.

 

[JDClapper]

Pretty good high level summary for this event, as it stands now.

[MaineJay]

SREFs are warm, not surprising seeing the NAM.

[jbrumberg]

This timeframe looks rather "interesting" weather-wise.  From the NWS/B-N Office morning discussion:

Spoiler

Guidance has come into somewhat better agreement that, though the
track of the secondary surface low passes in the vicinity of Cape
Cod, enough cold air hangs on for a 6-10 hour period of snow in the
high terrain of the Berkshires and even the Worcester Hills before
sunrise Wednesday. Bufkit soundings show a subfreezing column
through 9 or 10Z (4 or 5 am) before warmer air arrives below 800 mb
and precip switches over to rain. As for snowfall amounts, we won`t
get into too many specifics at this time range, but ensemble
guidance suggests around 1-3 inches of snow for the high terrain.
The GEFS is less excited about the highest terrain seeing AOA 3
inches (30-60%) compared to the EPS (50-80%). Elsewhere, expect rain
throughout. What is more certain is the strong dynamics accompanying
this system with a deep mid level shortwave and a 55 to 60 kt LLJ.
This, combined with ample moisture (PWATs approaching 1 inch or 200%
of normal), will lead to widespread rainfall of 0.5 to 1.5 inches.
Ensemble guidance indicates the best potential for AOA 1 inch of
rain to be over CT/RI/and southeast MA in close proximity to max
forcing from the surface low. This would place the greatest wind
threat over these same areas; we may see wind gusts of 50 to 60 mph
mix down over Cape Cod and the islands. EPS guidance places the
chance of 58+ mph wind gusts at 40-50% for the outer Cape during the
day Wednesday.

 

We'll see.

[StretchCT]

Gonna be a rough winter if this keeps up at 3-4 days out. 

 

[StretchCT]

At least I can spot a trend in the Euro

[Penn State]

48 minutes ago, StretchCT said:

Gonna be a rough winter if this keeps up at 3-4 days out. 

It gets worse.. I know this is off the topic of this thread, but the next wave has huge timing differences for the 26th (ish), and then the Euro and GDPS have been similar for the 28th-29th.. but the GFS isn’t even close to those. Wild. 

[ionizer]

8 hours ago, 1816 said:

Kind of off topic for this storm but it feels to me like the models have been getting worse the last few winters. More wild swings and taking to the last hour to get things figured out. Goes for all of them. 

Who knows what factors are causing this but I would guess the atmosphere being so different from the historical norms that the models use has a lot to do with it. My seasonal prediction for this winter is that this model struggle is going to be worse than ever. We may be able to get ideas of stuff from range but specifics are going to be hard to come by.  May be more useful to pay attention to the organic forecasts bsr etc than the models. 

I for one welcome our new AI model overlords.

[PA road DAWG]

Next Saturday looking nice! 

[NEPAsnow]

2 hours ago, PA road DAWG said:

Next Saturday looking nice! 

lets hope

 

[MaineJay]

Some ambitious EPS members in there. Maybe my little elevation can squeeze out 2 inches.  No an ideal CAD setup with high pressure departing to the SE.

 

[MDBlueridge]

Its that time of year again! I always love how 3k outlines the ridges with temps. Looks like just a little ice then nice warm rain down this way 

[JDClapper]

18 hours ago, PA road DAWG said:

Next Saturday looking nice! 

It is? 🤔

Wondering if we'll see our first wet flakes mixed in tomorrow before it goes to all 34-36 degree rain. 😃

[StretchCT]

3 hours ago, MDBlueridge said:

Its that time of year again! I always love how 3k outlines the ridges with temps. Looks like just a little ice then nice warm rain down this way 

I always liked what happened to the 850 line temps out west.

And how the NAM3k captures the valleys.  Its amazing how much of the west is over a mile high. 

And the 700mb shows the peaks

Edited November 20, 2023 by StretchCT

[JDClapper]

Juicy

 

[jbrumberg]

I does look like higher elevations in western MA may see 1" - 3" of snow tomorrow evening before it changes over to rain.

A snow graphic:

[TheRex]

BTV's snowfall map with the higher amounts to my south.  @telejunkieshould be in a good location for this system.

Quote

 

[JDClapper]

Looks like SCPA getting some winter.. State College not so much. It was 33 when I came down at 6:00, so that is pretty much that for any wintery surprises in my area.

 

[jbrumberg]

The NWS/B-N Office has issued a WWA for the higher elevations in western and central MA.

Spoiler

...WINTER WEATHER ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO
7 AM EST WEDNESDAY...

* WHAT...Snow. Total snow accumulations of 2 to 4 inches.

* WHERE...Western Franklin and Western Hampshire Counties.

* WHEN...From 7 PM this evening to 7 AM EST Wednesday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning commute.

* ADDITIONAL DETAILS...Snow developing between 8 and 10 PM
  changing to rain by 6 AM. A brief period of freezing rain is
  possible during the transition from snow to rain.

I anticipate seeing some accumulating snow tonight  (1" - 4") before it changes over to rain tomorrow.

From this morning' discussion:

Spoiler

Rain, snow and timing...

Fairly potent northern stream trough will be approaching from the Gt
Lakes tonight and moving across New Eng Wed. Primary low pres will
be moving into the Lakes but a secondary low forecast to develop
over the mid Atlc region and tracking across the coastal plain
during Wed. Strong isentropic ascent ahead of this low pres will be
enhanced by a strong low level jet (2-3SD above normal) bringing
rain heavy at times across SNE, especially late tonight and Wed
morning along the nose of the low level jet. Meanwhile, antecedent
cold air leftover from strong high pres will lead to a period of
accumulating snow for the higher terrain in the Berkshires and
Worcester hills before changing to rain by daybreak.

Given the very dry air in the 850-700 mb layer, precip will be
delayed somewhat starting 8-10 pm in western New Eng and 10 pm to
midnight in eastern New Eng. Wet bulb cooling in the lower levels
will help to lock in the cold air in the higher terrain where
soundings support mostly snow tonight, but low level warming will
eventually lead to a changeover to rain by daybreak. A brief period
of freezing rain is possible during the transition but this looks
more like a snow to rain scenario as warming is occurring in the low
levels. Marginal surface temps and some melting will keep SLR below
10:1 so our current thinking is accums 1-4 inches over the higher
elevations with the highest amounts in the northern Berkshires where
a winter weather advisory was issued. Could see up to an inch accum
in the MA Pike to I-495 corridor before it all gets washed away.

For rest of SNE, rain will be heaviest during the overnight into Wed
morning, then dry slot moves in with rain tapering off in the
afternoon from west to east. Expected rainfall will 1 to 2 inches,
heaviest across CT, RI and SE MA. Not expecting any flood concerns
other than the typical nuisance minor poor drainage flooding.

 

Now that I got the 🚜 running; bring it on.🤪

Edited November 21, 2023 by jbrumberg

[JDClapper]

Rain, 35. I might have heard a couple tings in the 5 mins I listened, but could also be my wishful mind playing tricks on me 😆

[TheRex]

BTV's forecast discussion.  It seems it is possible some of the higher terrain may see up to 6".  I'm expecting it to start as snow here and transition to rain during the night.

Quote

Previous Discussion...There were no startling changes to the
expected conditions for the pre-holiday storm system tonight
into Wednesday. The main adjustments continued to concern timing
with forecast consensus favoring a slight delay in time of
arrival from around 4pm to between 4 and 6 pm this evening for
northern New York. This timing slip could favor continued
entrenchment of colder air near the surface supporting slightly
higher ice accumulations for northern New York. There were also
some increases in liquid equivalent amounts which favor slightly
higher localized snowfall amounts for the Adirondacks and Green
Mountains. Otherwise, the expected storm evolution remains
unchanged with snow overspreading the North Country ahead of
warm air advection. As warm air overruns surface colder air,
chances for freezing rain and sleet increase, especially in the
6pm to midnight time frame for northern New York. With continued
warm air advection, a transition to mainly rain is expected
except for higher elevations where atmospheric profiles continue
to favor a mix of precipitation types.

Ice...Ice totals were marginally increased for northern New York
with higher QPF amounts and an extension of colder near-surface air,
especially towards Massena. Most likely amounts of flat ice
accretion are generally around 0.05-0.15" for portions of northern
New York with a trace to 0.05" for Vermont mainly away from Lake
Champlain. There are some indicators suggesting that there is about
a 10% chance of around 0.25" of ice towards Massena, but that will
largely depend on how whether winds aloft can thin the near surface
cold air enough to allow a transition to rain more quickly. Higher
elevations of Vermont are more susceptible to ice with timing and a
deeper layer of near surface cold air in northeastern Vermont
limiting accretion for lower elevations. Best chances for ice
accretion at lower elevations with be mainly in Windsor Country. The
slight southeasterly ridge level winds may allow for just enough
downsloping off the Greens to preclude accretion of ice for
locations west of the Greens below 1500ft. The biggest question
remains whether surface temperatures will be at freezing when the
precipitation type switches from snow to rain. There could be a few
spots mainly between 500-1500ft that see a trace of ice through this
mechanism.

Snow...General amounts haven`t changed much; still expected 2-4
inches for the Adirondacks and southern/southeastern Vermont.
However, the increase in QPF has nudged the potential slightly higher
for a few very localized spots to see 6 inches; can`t completely
ruled out these amounts. Elsewhere, only a dusting to less than 2
inches are expected. Character of the snow that falls will be wet
and slushy with ratios less than 10:1; this means that the snow may
be more difficult to drive through.

Winds...After a calm, cold start, winds will increase this afternoon
and evening mainly out of the south. The St. Lawrence Valley will
maintain a northeasterly component due to low position and terrain
influences. Breezes tonight will be strongest in the northern
Champlain Valley and for downslope spots off of the Greens where
gusts will generally be around 20-25 mph and periodically up to 35
mph. Elsewhere, gusts will be around 20 mph. Periods of moderate
precipitation will dampen these winds.

Temperatures...It`s quite chilly this morning with temperatures in
the teens for most spots and single digits for northeastern Vermont
and colder hollows of the Adirondacks. Temperatures will warm above
freezing for broader valleys with freezing temperatures more
entrenched in the Adirondacks and along/east of the Green Mountains.
It seems reasonable that northeast flow will aid in cooling
temperatures below freezing despite cloud cover for northern New
York while the Champlain Valley will be more questionable. Winds may
keep enough mixing and/or downsloping to keep conditions just above
freezing through midnight before warm air advection wins out and
increases most locations above freezing by Wednesday morning.