12/14-12/15 Winter Storm

[LVblizzard]

Looks like the wintry start to December will continue with, at the very least, a front-end thump of snow and ice over the weekend. Today's 12z Euro had the snowiest solution so far, with a 6-12" SECS for I-95 N&W. Other models are less bullish, with a general 1-3" or 2-4" event before ice and rain. A strong high pressure system is forecast to be over New England and southern Canada at this time, so this threat definitely bears watching, even if the track is less than ideal.

[RedSky]

Redevelopment off south jersey happens just in time on the 12z ECM run to create a decent sized snow or snow to ice event for the N&W Philly crowd I95 dividing line

 

* actually not bad for those east of I95 either

[ChescoWx]

Wxsim has an all frozen scenario for NW Chesco using the 12z GFS/NAM combo
2"-4" of snow/IP starting around noon changing to ZR late day and continuing as ZR overnight - total frozen 0.97" liquid

[Ralph Wiggum]

This system appears as though the arctic hp associated with a piece of the split pv is in a worse spot than the dec 8 storm. Therefore it allows for warming as the storm transfers to the coast. Not sure I'm loving this setup...maybe some snow or a mix over to rain except the usual interior areas. Exact details later but needless to say i'm not on board with the 12z euro.

[Ralph Wiggum]

I also wonder what role the breakdown of the -epo will play in evolution of this storm.

[RedSky]

0z ECM has a weak wave on the weekend all snow 2-4"

[kpantz]

06Z GFS also weaker.  Northern stream is even less involved than depicted by 00Z so a weak surface low slides northeastward off the coast.  Mixed bag of relatively light precip for the area.

[Ralph Wiggum]

6z gfs develops secondary about 150 miles farther se this run vs 0z....colder run less qpf. Snow to a mix phl and immediate burbs rain s and e. Better trend....this won't be a monster storm down this way with no blocking and a relatively progressive flow forecast. Euro from 0z may not be too far off of apparent weather with a weakish wave swinging thru yielding a general tame snowfall but not sure I agree with little redevelopment and the amount of llc it portrays attm.

[ChescoWx]

_{No surprise expect colder solutions as JB alluded to yesterday - cold begets cold snow begets snow - one thing for the further N and W burbs do not see freezing so a wintery mass at the least!}

[Quakertown needs snow]

I'd take another 2-4 on top of what we have.

I'll pass on freezing rain, thanks .

3rd event beofre 1st day of winter. Not bad at all.

[kpantz]

It's something, yeah.  Not a blockbuster, but I suppose we shouldn't get greedy.  If you are still hoping for a SECS, then you should pin those hopes on the 06Z NAM at 84 hours (you can stop laughing now).

 

[JCT777]

I'd take another 2-4 on top of what we have.

I'll pass on freezing rain, thanks .

3rd event beofre 1st day of winter. Not bad at all.

 

I couldn't have said it better.  And definitely rather see snow or sleet than freezing rain.

[White_Mtn_Wx]

I'd take another 2-4 on top of what we have.

I'll pass on freezing rain, thanks .

3rd event beofre 1st day of winter. Not bad at all.

heck yes

[Ralph Wiggum]

I hate using the nam for extended but showing 850 low still over ohio yet a hair weaker. Suggests snow to slop along i95 verbatim

[ChescoWx]

Latest Wxsim with 6z data still keep NW Chesco all frozen this weekend

[kpantz]

NAM lays down a 2-3 inches of snow at ABE before the end of the run.  Synoptically, it has the look of something that gets its act together a little late for a big storm here, but interior SNE could cash in if one were to let the NAM play out further.

[LMolineuxLM1]

The trends I see is further SE now not as strong but could blossom and could be a moderate event. Better then snow to ice.

[RedSky]

12z gfs is not a juiced system this weekend. Couple inches front end snow then a warm punch with freezing drizzle similar to the past weekend storm without the big frontogenic band

[Ralph Wiggum]

The big caveat in this forecast as I've been buzzing about is the strength and placement of the 850 low which shows up over the Ohio valley on majority of guidance. This in itself should be a huge red flag for anyone expecting much snow along i95 or the coastal plain. Hp also in a less desirable position than last weekend yeilds more wet than white imho. Lets hope we can reverse these trends in future runs but not looking great right now for snow mongers in the areas I mentioned. This appears like a classic new england snowstorm to my eyes attm.

[kpantz]

I don't know if I'm really worried about the 850 low (if you can even really call it that) placement here.  To me, the bigger (non) story is the weakness of the upper levels.  This thing doesn't have the support for deep cyclogenesis, at least not until it's far too late.  Yes, the mid-levels warm up and it's enough to throw some of the interior over to freezing rain, but the dynamics aren't there to really make this "one that gets away" - more like "one that we never really have."  Let's take whatever WAA frozen/freezing precip we get and remember it's only mid-December.

[Ralph Wiggum]

That's not gonna get er done...a ssw flow is the kiss of death. I'll wait to see what the euro says but I think The writing is on the wall.

[kpantz]

That's not gonna get er done

That's still snow over my house.

 

But seriously, this is not a strong system as modeled this morning.

[chrisNJ]

New HPC likes the idea of heavy snow over portions of the northeast.

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1107 AM EST WED DEC 11 2013

VALID 12Z SAT DEC 14 2013 - 12Z WED DEC 18 2013

...WINTER STORM LIKELY FROM THE NORTHERN APPALACHIANS INTO THE

NORTHEAST THIS WEEKEND...

...PATTERN OVERVIEW...

A MEAN LONGWAVE RIDGE IS EXPECTED TO PREVAIL ALONG THE WEST COAST

FOR MOST OF THE UPCOMING MEDIUM RANGE PERIOD WITH A MEAN TROUGH

BEGINNING TO DEVELOP ACROSS THE PACIFIC NORTHWEST LATE...WHILE A

MEAN LONGWAVE TROUGH CONTINUES FROM HUDSON BAY SOUTHWARD INTO THE

MISSISSIPPI VALLEY.

...MODEL PREFERENCES/UNCERTAINTY/SENSIBLE WEATHER HIGHLIGHTS...

MODEL CONTINUITY AND AGREEMENT OVER THE LAST SEVERAL CYCLES HAS

IMPROVED SLIGHTLY...WITH THE OPERATIONAL GFS AND ECMWF AND THEIR

RESPECTIVE ENSEMBLE MEMBERS GENERALLY CONVERGING UPON ONE

ANOTHER...WITH THE GFS SIDE OF THE SPECTRUM SLOWING AND ECMWF SIDE

ACCELERATING. THE SHORTER WAVELENGTH ASPECTS EMBEDDED WITHIN THE

BROADER FLOW THAT WILL ULTIMATELY DETERMINE THE SENSIBLE WEATHER

REMAIN SPLIT...WITH INTERACTIONS OF MULTIPLE STREAMS CREATING NEAR

AVERAGE UNCERTAINTY OVERALL...WITH ABOVE AVERAGE CONFIDENCE EARLY

IN THE PERIOD...AND BELOW AVERAGE CONFIDENCE LATE.

FOR THIS WEEKEND...DAYS 3/4...MODEL AGREEMENT IS ABOVE AVERAGE FOR

LOW PRESSURE TO MOVE FROM EAST TEXAS ACROSS THE APPALACHIANS TO

THE NEW ENGLAND COAST...WITH HEAVY SNOW LIKELY FOR PORTIONS OF THE

NORTHERN APPALACHIANS INTO THE NORTHEAST. EXACTLY HOW MUCH SNOW IS

LESS CLEAR. MODEL QPF VALUES VARY BY A MODEST AMOUNT...WITH THE

FASTER GFS AND GEFS MEMBERS PRODUCING MORE ROBUST TOTALS FOR

PORTIONS OF THE NORTHEAST COMPARED TO THE SLOWER ECMWF AND ITS OWN

ENSEMBLE MEMBERS. THE SLIGHTLY SLOWER ECMWF SCENARIO IS PREFERRED

BUT NOT ENTIRELY DUE TO THE CONTINUED SPREAD ASSOCIATED WITH THE

MULTIPLE STREAMS.

[Sophisticated Skeptic]

that was issued before the 12z Euro.  :-/

 

their already crying about it in NYC thread. 

 

but their moods should stabilize after tonight's 0z NAM.  

[Ralph Wiggum]

And I was told over there an 850 low passing to our n and w "means nothing in this setup". Umm, ok. That subforum is a mess.

[iceman56]

And I was told over there an 850 low passing to our n and w "means nothing in this setup". Umm, ok. That subforum is a mess.

I remember DT preaching that an ULL over OH was the kiss of death for meaningful snow in the northern mid-Atlantic and I also

remember he was right.

[Heisy]

Does the EURO show any kind of front end thump for I-95?

[famartin]

I remember DT preaching that an ULL over OH was the kiss of death for meaningful snow in the northern mid-Atlantic and I also

remember he was right.

Define "meaningful".  This time of year, and after the last two winters, a few inches can be meaningful

[RedSky]

ECM is 3-5" in sepa followed by freezing drizzle after mild air moves in. Models have become fairly close for this system.

 

Not likely to be a major snowstorm for anybody outside new england but a good moderate event

[iceman56]

Define "meaningful".  This time of year, and after the last two winters, a few inches can be meaningful

Well, weenies were hyped up over clown maps showing 10+ inches and we wound up with a coating before going to rain.

A few inches is always meaningful in this neck of the woods, but one has to keep their expectations in line with climatology.