12/10-11 Disco / Obs - Rain/Snow/Wind Event

[nj2va]

Thread for the Sunday - Monday rain/snow/wind event.

[Chris78]

1 minute ago, nj2va said:

Thread for the Sunday - Monday rain/snow/wind event.

Bring it home....

[J.Mike]

I've got goosebumps 

[NorthArlington101]

I've been straying away from looking at the means of the ensembles as they are super easily skewed. WxBell as a new tool as of this year (I think?) that displays the 10th/25th/50th/75th/90th percentile of snow accums for an event based on the ens. 

It's not as sexy as the ens mean, but this is first flakes for most and a "legit" first event out west. And it's improving run-over-run.

EURO ens not as generous, fwiw.

[Weather Will]

WB 6Z EURO snow depth map, I hope my dusting verifies!

[H2O]

Fringed

 

But rather have something over nothing so if I see snow then all good to me

[Weather Will]

Nice drought denting storm....and a little breezy....WB 6Z EURO.

[CAPE]

Nice disco from Mount Holly-

Strong trough and cold front will begin to influence the weather
more noticeably Saturday night, with increasing high and mid
clouds. The warm front will still be struggling to lift north,
so cooler temps prevail, but we will stay above freezing at
least, with 30s north and 40s elsewhere. Some patchy
fog/drizzle/mist may again develop late Saturday night.

Sunday, the warm front is finally sent well north of the region
as the southerly low-level jet ahead of the approaching cold
front strengthens rapidly. This will bring southerly winds which
may gust 30-40 mph along with increasing coverage of showers and
possibly even some embedded thunderstorms. The forcing with the
upper trough is quite potent and moist flow significant, so
locally heavy rain may start overspreading the area. The
southerly flow should bring plenty of warmer air northward as
well, so temps surge into the 60s for most.

However, the most active weather likely waits until after
nightfall Sunday night. Southerly winds may gust up to 50 mph
along the coast, maybe even a little higher, thanks to the
extremely powerful low-level jet. Any stronger cells could even
mix down winds up to severe limits. The heaviest rainfall also
will occur as the forcing maxes out just ahead of the
approaching cold front, with totals likely exceeding 2 inches
across much of the area, with localized flooding being a concern
along with perhaps some stream/small river flooding in the
coming days. A strong push of wind may then occur as the cold
front blasts across the region overnight, with widespread wind
advisory gusts possible and perhaps some localized gusts near
severe limits with the front. Temps likely stay in the 50s to
low 60s until the front passes, then rapidly drop into the
40s. A quick changeover to snow with modest accumulation is
possible late in the Poconos.

[Interstate]

Because we do cold air chasing a cold front for snow around here. 

[jewell2188]

Cold chasing precip…..works so well east of the mountains lol. 

[CAPE]

Decent early season nearby chase opportunity for those jonesing for snow.

Cold front pushes east of the spine of the Appalachians Sunday
with strong frontogenetic forcing shown, producing widespread
rainfall. Trend has been for somewhat less QPF in the northwest
but still 1-2 inches over the southeast forecast area. NBM 90th
PQPF over Preston and Tucker Counties still around 3" so
potential for decent rises in the Cheat and Mon Basins.

Confidence is low on how much snow will fall as the
precipitation is ending over the lower elevations. Still looks
good for several inches of snow in northwest flow and upslope
over the Laurel Highlands and the Preston/Tucker County areas of
West Virginia Sunday night and Monday and this will likely
require a Winter Weather Advisory at some point.

[nj2va]

Adding LWX's discussion too.  Another dent in the rainfall deficit.

Therefore, widespread rain is expected across the area Sunday into
Sunday evening and it will be breezy. A line of heavier showers
and perhaps a thunderstorm will most likely accompany the
frontal passage Sunday afternoon/evening. Given the strong winds
aloft, this has the potential to mix down gusty to perhaps even
locally damaging wind gusts. One mitigating factor will be the
lack of instability that is progged in the models. It will be
difficult to get instability rooted within the boundary layer.
Therefore, certainty for damaging wind gusts is low at this
time. A soaking rain is expected given the dynamics and moisture
associated with this system. Rainfall amounts around 1-3" are
most likely. The recently dry conditions may minimize the flood
threat, but localized flooding cannot be ruled out given the
higher rainfall amounts and the fact that rainfall rates may be
heavy at times with the frontal passage.

Colder air will move in behind the front, first later Sunday
evening in the Allegheny Highlands and then Sunday night from
northwest to southeast across the rest of the area. With the
upper-level trough axis lagging behind the frontal passage by a
few hours or so, this suggests that there will be some
anafrontal characteristics to the boundary. Therefore, moderate
precipitation is expected for a few hours or so behind the cold
front before drier air eventually works its way in overnight.
There will be enough cold air for rain to change to snow in some
areas. As of now, it appears that the best chance for
accumulation will be along the ridges of the Blue Ridge, Potomac
Highlands, and Allegheny Highlands where cold air will move in
sooner. For locations along and west of the Allegheny Front, an
upslope component to the low-level flow will cause additional
snow showers to last longer behind the cold front, enhancing
potential for accumulating snow. Winter weather headlines may be
needed for the mountains. For the valleys, any chance for
accumulating snow is low, but this will continue to be
monitored.

[WinterWxLuvr]

 

If you know, you know

[mattie g]

It's early-season potential, even if a long shot and wouldn't amount to much.

Certainly worth tracking for a couple days.

[NorthArlington101]

12z GFS. Precip cuts off faster/isn't as intense on the backside as the NAM.

[SnowenOutThere]

Gfs looks somewhat improved, gets snow closer to the metro areas than 6z

[mdhokie]

Ravens game gonna be wet!

[Eskimo Joe]

1 hour ago, jewell2188 said:

Cold chasing precip…..works so well east of the mountains lol. 

Next week we are installing mesonet sites in western Maryland. This will provide additional ground truth in the data space landscape.

[stormy]

Lets beef it up a little!   6 inches at my place!!!

[Eskimo Joe]

Just now, stormy said:

Lets beef it up a little!   6 inches at my place!!!

Psuhoffman gets winter saved 

[EastCoast NPZ]

Trashcans across the region are hurriedly taking precautions. 

[87storms]

5 minutes ago, EastCoast NPZ said:

Trashcans across the region are hurriedly taking precautions. 

lol.  I'm not tracking snow for this event.  Absolutely, not worth it.  However, I will be tracking the storm itself as it looks interesting and may provide some needed rainfall.  Might have to bike a trail or two today...I've been slacking on that.

[nj2va]

Any snow is good snow, even if its snow TV in the metros.  It'll make the Christmas decorations even more festive.  

[mattie g]

5 minutes ago, nj2va said:

Any snow is good snow, even if its snow TV in the metros.  It'll make the Christmas decorations even more festive.  

100%.

It would probably be annoying to "have to" track something like this at the beginning of February if we hadn't seen anything of note prior to that, but it's barely into December at this point. Let's track away!

[EastCoast NPZ]

9 minutes ago, 87storms said:

lol.  I'm not tracking snow for this event.  Absolutely, not worth it.  However, I will be tracking the storm itself as it looks interesting and may provide some needed rainfall.  Might have to bike a trail or two today...I've been slacking on that.

Agreed.  The rainfall is what interests me.  In this pathetic region, rainfall has become as exciting as snow used to be.

[mappy]

lolololol 12km NAM has 7" for my back yard. That's nonsense. 

[87storms]

Any snow is good snow, even if its snow TV in the metros.  It'll make the Christmas decorations even more festive.  

I’m gonna welcome it. I just know these setups are typically nowcast for our region. I haven’t looked at this event too closely, so maybe it surprises. Higher elevations will be in better shape.

[H2O]

14 minutes ago, mappy said:

lolololol 12km NAM has 7" for my back yard. That's nonsense. 

0.8 for mine.  That will verify

[WesternFringe]

GFS has mby fringed on the east of the best snow, NAM has me fringed on the west.  Seems legit- lol.

[NorthArlington101]

EURO is holding serve with a flip to flakes at the end.