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

[ionizer]

Just now, Penn State said:

Ruh-Roh

 

is that just torrential downpour of rain or something else hitting everyone on the east coast?  i can't tell

[Penn State]

GDPS 👀

[Penn State]

1 minute ago, ionizer said:

is that just torrential downpour of rain or something else hitting everyone on the east coast?  i can't tell

lol.. Indeed. But that secondary low.. I mean, it’s making it interesting for folks like me in the interior. 

[Penn State]

GFS also popping the secondary further east.. 

[Penn State]

Looking at the 500mb.. You can see the difference. The GFS has a more neutral tilt at hour 84. The GDPS and ICON are still positive, and the implications are represented down the road. Long range NAM and RDPS.. and even the UKMET are more positive. 

[MaineJay]

ECMWF with some "baby got back.. end snow". These anafrontal events aren't super common, but some flakes after the rain could be possible.

How weak will the parent low get over the next few cycles. These deep lows in the D5+ range just don't materialize. Models are over phasing quite often.  

[JDClapper]

Even 0z EPS with a baby bump now for Central PA. Yesterday 12z was cause for writing everything off forever, but now hope has arrived. 😅

 

Edited December 6, 2023 by JDClapper

[MaineJay]

3 minutes ago, JDClapper said:

Even 0z EPS with a baby bump now for Central PA. Yesterday 12z was cause for writing everything off forever, but not hope has arrived. 😅

 

[MDBlueridge]

1 hour ago, MaineJay said:

[jbrumberg]

I would like to see some backend snow with this pending FROPA, but at this point the NWS/B-N Office is looking at an all rain event for southern NE:

Spoiler

Sunday through Monday: As advertised, this is the most active period
of the forecast. From a synoptic point of view, the mid-level ridge
shifts east with decreasing 500mb heights over southern New England.
An amplified trough digs south, before becoming negatively tilted, a
signal for potential intensification. At the surface, there remains
a good deal of uncertainty with the origin of a developing low
pressure system, global guidance doesn`t have a good handle on this
as of yet. But as of early Sunday there is a weak low around the
Great Lakes, which the GFS, ECMWF, and GEM show deepening while
moving east. Parked off shore is a 1030mb high, generating a tight
pressure gradient over the northeast.

A bit of better news, Sunday is beginning to look like a drier day,
at least during the daylight hours. A forward shift in the timing
likely to bring a multi-hazard system late Sunday night into Monday.
Keep in mind there remains a bit of uncertainty with the fine timing
of the event, but what has remained consistent, the strong southerly
winds, periods of heavy rain, and potentially dangerous marine
conditions.

GFS, ECMWF, and GEM continue to indicated a robust LLJ with 900mb
wind roughly between 70 and 90 knots. It is still to early to say
how much of the wind could mix to the surface, but even a fraction
would lead to fairly gusty conditions. As you could imagine the
strong wind will lead to building seas, some guidance suggests some
rather high waves by Monday morning. On top of dangerous conditions
on the water, potential coastal flooding if max surge were to
coincide with the high tide, in addition to the potential for
coastal erosion. Lastly, WPC has placed much of western MA and CT
in a marginal risk for excessive rainfall for this system. Ensembles
are in pretty good agreement we will see at least 1/2 inch of rain,
with modest probabilites of up to an inch west of Route 146. Even
low probabilites, less than 20 percent, of 2 or more inches of rain
in far western MA.

In addition, will be quite warm for early December, highs in the mid
and upper-50s on Sunday, then cooling off to near normal highs on
Monday near 50 degrees. More to come over the coming days, stay
tuned!

Tuesday into Next week: Trending drier and slightly warmer than
average, per CPC there is between a 40 and 50 percent chance for
above normal average temperatures.

Highs trend in the mid-40s where as lows trend towards the
mid-30s.

 

😭

[TheRex]

12Z GFS showing heavy snow for Monday morning in the same places that have been getting the heavy snows so far this winter.  Jay Peak, which is in northern VT along the Canadian border, is reporting 91" of snow so far this winter.  Too bad you can't get there from here.

Quote

 

[TheRex]

This is the AI generated Euro snowfall depth map for Monday and it looks like it expects snow to be on the ground in some places in the northeast that hasn't seen much snow this year.  

Quote

 

[NEPAsnow]

This would have some Heavy Precip rates as the temp crashes and switches to some heavy snow for a period.

Edited December 6, 2023 by NEPAsnow

[JDClapper]

We did this last year, where most models, and to the extreme GFS, showed backend snow. Talking 10-15" on some GFS runs.

It rained, the front came through and the storm was over. Fool me once! 😃

[MDBlueridge]

3 minutes ago, JDClapper said:

We did this last year, where most models, and to the extreme GFS, showed backend snow. Talking 10-15" on some GFS runs.

It rained, the front came through and the storm was over. Fool me once! 😃

Hard to argue with this. Backend snow always favors elevation as well where temps/atmosphere crash the quickest. 

[JDClapper]

Imma still watch every model run though

[buxtonian]

Is this going to be another year of Great Lake Cutters???

[JDClapper]

1 minute ago, buxtonian said:

Is this going to be another year of Great Lake Cutters???

Yes, maybe. Could be different though.

[telejunkie]

7 minutes ago, buxtonian said:

Is this going to be another year of Great Lake Cutters???

certainly looking like an el nino pattern for now...

[JDClapper]

14 minutes ago, MDBlueridge said:

Hard to argue with this. Backend snow always favors elevation as well where temps/atmosphere crash the quickest. 

 

[telejunkie]

46 minutes ago, TheRex said:

12Z GFS showing heavy snow for Monday morning in the same places that have been getting the heavy snows so far this winter.  Jay Peak, which is in northern VT along the Canadian border, is reporting 91" of snow so far this winter.  Too bad you can't get there from here.

 

The only way to get there is from Montreal....

Bolton is reporting 71"...also pretty impressive. Bromley still at 18" for the season....#sadtrombone (but at least we don't have much to lose when this storm blows through)

Burlington's morning disco:

Quote

Rainfall amounts of 1-2 inches still in the cards along with significant loss of snowpack across central-northern mountains as the existing snowpack is above normal and wet in nature with dewpoints likely in the 40s and strong winds all contributing to significant loss. Ensemble long range hydro guidance and SPORT suggests mountain watersheds will possibly/likely see action to minor flood levels based on current assumptions. Slightly concerned that some convection could get involved which would potentially lead to isolated flash flooding, not that uncommon with timing of max snowmelt with convective rains. Still way ahead but stay tuned.

 

Edited December 6, 2023 by telejunkie

[SnowloverSid]

18 minutes ago, buxtonian said:

Is this going to be another year of Great Lake Cutters???

Regardless of El Niño or La Niña, the pattern has supported cutters, notably in the Dec, 20-25 period.

[MaineJay]

Don't really think it's possible to "get there", but the ECMWF is still pushing east.

[MaineJay]

1 hour ago, JDClapper said:

 

[MaineJay]