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

[JDClapper]

PSU's call (they don't usually post on the weekends)

 

[MDBlueridge]

Plumage jump even in the cumberland valley. 

No way. 

[JDClapper]

5 minutes ago, MDBlueridge said:

Plumage jump even in the cumberland valley. 

No way. 

Yeah, 21z went bonkers .. mean of 4" up here (8 members over 4").. that's up from 2" at 15z

[JDClapper]

[JDClapper]

4 hours ago, so_whats_happening said:

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!'

Yaas!  Let go and have some simple fun with us for a spell.  🙂  

[Rush]

46 minutes ago, MDBlueridge said:

Plumage jump even in the cumberland valley. 

No way. 

Frederick is almost up to 3" now.  The SREF is the only model that even gave me digital snow last year.  Nice to see it back at work this winter.

[JDClapper]

Trending more negative late Sunday, since the 12z run.

[JDClapper]

Appalachian special

 

[JDClapper]

Deeeeamn.

[JDClapper]

Last frame of 3k NAM.  Not as generous with snow to the west of me, but fairly similar from mid-state east.

[JDClapper]

Then there's the FV3 through hr 60 haha

[Penn State]

35 minutes ago, JDClapper said:

Appalachian special

 

Would absolutely love this.. NAM, why do you tease me so? 

[TLChip]

The trend is your friend? I'll take the cooler trends all day.

Edited December 9, 2023 by TLChip

[Penn State]

I feel like this GFS run will either be an epic run or totally deflate the ballon lol 

[Penn State]

Not bad.. 

[Penn State]

SREF for Hagerstown, MD. Substantial. 

[MaineJay]

6z NAM isn't making too many friends.

[MaineJay]

A multitude of hazards. 

GYX

Quote

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Overview: Significant storm impacts the area to start the
period. This will be followed by trofing and westerly flow. This
will generally be drier but with upslope snow showers and cooler
temps.

Impacts: Three primary hazards are in play with the Sun/Mon
storm. Strong winds near the coast may lead to power outages.
Widespread moderate to heavy rainfall may lead to small stream
and poor drainage flooding...potentially even mainstem rivers
if enough snow melt occurs. Finally rain may change to snow fast
enough on the backside of the system for a short duration but
heavy/wet snow accumulation. This could also add to power outage
concerns.

Forecast Details: Significant cool season storm to affect the
forecast area Sun night into Mon. Multiple headlines have been
issued to cover various hazards thru the event.

Strong forecasts for low pressure have led to strong forcing for
ascent and resulting QPF has gone up today. Mean forecasts are
now comfortably around 1.5 inches...with higher totals where the
strongest forcing and upslope is located. So a flood watch has
been issued. See the Hydrology section below for more details on
that threat.

Coincident with the flooding threat is the threat of strong
winds. Model guidance has really ramped up LLJ forecasts today
and continue to hold serve. NBM mean gusts are quite robust at
this range...but entirely supported by deterministic and
ensemble guidance. I tried not to go too overboard with this
update...and allow some room to adjust up or down as necessary.
However...NAM and GFS forecast winds at 925 mb approaching 80
even 90 or 95 kt is on the extreme end of model climatology.
Taking half of that wind to the surface is easily wind advisory
criteria...and I felt there is more than enough reason for a
high wind watch given 50 percent confidence level. If models
continue to forecast these kinds of low level winds...an
increase in forecast gusts is reasonable to expect.

Finally there is the threat from a rapidly cooling column as low
pressure deepens. On the northwest side of the system temps will
cool enough to flip rain to snow. In fact forecast soundings
show potential to flash over to heavy snow at the changeover.
Even if this window only lasts an hour or two...a quickly 2 to 4
inches is possible. North of the notches 6 or more inches
remains a possibility. While the column will be cooling...it
will also be near isothermal around freezing as snow starts. So
a wet sticky snow is possible...and additional power outages
that are not wind related could result. There is more time to
iron out that snow forecast however...as the change over will
not come until mid morning Mon or later.

 

 

[MaineJay]

Last 7 NAM. 6z is particularly weaker/slower/east-er.

[Rush]

2 hours ago, MaineJay said:

6z NAM isn't making too many friends.

SREF went down too.  So it begins...

[JDClapper]

It wouldn't be a winter storm without not knowing WTAF is going to happen until it happens 🙂

SFEF 1"+ prob trend from 4pm Sun-4pm Mon.. pretty clear eastward, weaker trend the past day. (Includes 9z, hot off the press)

 

Edited December 9, 2023 by JDClapper

[Hiramite]

[so_whats_happening]

20 minutes ago, Hiramite said:

Yep about what i expected to see. Should have also included VT with central and upstate NY. Ill enjoy the mood flakes as the system exits and move on. My personal hope is to at least beat the last 2 years of snowfall, which we are already pretty close to beating last years!

Im more so happy to see the increase in moisture. Hope we can get a solid foot storm in the future to slow the feed of rain into the groundwater.

[so_whats_happening]

34 minutes ago, JDClapper said:

It wouldn't be a winter storm without not knowing WTAF is going to happen until it happens 🙂

SFEF 1"+ prob trend from 4pm Sun-4pm Mon.. pretty clear eastward, weaker trend the past day. (Includes 9z, hot off the press)

 

Lol models am i right.

[HVSNOWSTORM]

6Z NAM