Dec 16-17 MidAtl/NE Storm, Reality: Short Range (0-4 Days Out) Forecasts Options

[NYCSuburbs]

Messy on the RGEM in terms of snow and ice north of me

http://collaboration.cmc.ec.gc.ca/cmc/cmdn...pe_gem_reg.html

Looks ugly for the high elevations. At least we still get a dusting before the changeover... not exactly sure how much the 0z showed but the 18z had up to an inch.

This post has been edited by NYCSuburbs: Dec 14 2012, 10:22 PM

[LoveNYCSnow]

Looks ugly for the high elevations. At least we still get a dusting before the changeover... not exactly sure how much the 0z showed but the 18z had up to an inch.

Yea I'm pretty sure neither of us are in particularly prone CAD locations. I think west of the hudson valley could be in for a nasty ice event Sunday night.

[NorEaster07]

KBOX snow map

[NorEaster07]

Quick look at the sounding from GFS for Hartford CT. Considering all the shuffling by models I honestly believe it did very well knowing where the snow accumulations would be. ( I-90 N) before the changeover south of VT.. there were some crazy runs showing accumlations further south but those werent the consistant ones.

[NYCSuburbs]

NAM keeps trending drier for the front end snow; might have to turn those front end flakes to a front end flake (obviously not that little but still less than before, basically just flurries).

I can't believe I could actually end up having gone through November and 2/3rds of December in Albany with barely 1 accumulating snow event less than an inch (according to KALB; I measured a bit more with the 12/1 event). I'll be back in Albany after a while in NE NJ, but an early end to a non-winter and a late start to the next winter is really making the wait for snow much longer than it should be.

[NorEaster07]

Wow... Bostons discussion very detailed and informative.. The entire thing is worth reading. They mentioned substantial analog events had ice observations and mention half foot into SNH.


http://forecast.weather.gov/product.php?si...p;highlight=off

A CLASSIC OVERRUNNING CASE WHERE WARM MOIST AIR IS ADVECTED NEWD
ISENTROPICALLY THRU BROAD MID-LVL ASCENT ACROSS LINGERING COOLER AIR
MASS AT THE SURFACE REMNANT FROM A DEPARTING ARCTIC HIGH. SOME
NOTABLE FEATURES:

- A MID-LVL RIDGE AXIS WILL DOMINATE THE INITIAL PD /SUBSIDENCE/...
GRADUALLY TRANSITIONING EASTWARD AS A SERIES OF SHRTWV DISTURBANCES
ADVECTING THRU THE LONGWAVE PATTERN AHEAD OF A NEGATIVELY TILTED
OPEN WAVE TROUGH ACROSS THE GREAT LAKES REGION.

- WHILE BROAD ISENTROPIC LIFT AND DIFLUENT MOTIONS ALOFT ARE
EXPECTED...THE ATTENDANT JET AXIS TO THE AFOREMENTIONED TROUGH IS
WSW-ENE ACROSS THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND. DEEP-LYR
LIFT ASSOC WITH THE LEFT-EXIT RGN OF THE JET AXIS WILL LIKELY BE
CONCENTRATED ALONG AND S OF SOUTHERN NEW ENGLAND /SPECIFICALLY IN
PROXIMITY TO THE MASS PIKE/. SUBSEQUENTLY HEAVIER QPF.

- MODEL 2M TEMPS ARE INDICATIVE OF A COLD AIR DAMMING SITUATION AT
THE SURFACE. WITH EXPECTED SURFACE EASTERLY FLOW AS THE ARCTIC HIGH
LIFTS NEWD AND A WARM FRONT APPROACHES FROM THE SW...LOW-LYING
LOCALES ARE ANTICIPATED TO SCOUR OUT EARLY /COASTAL PLAIN/...
WHEREAS ACROSS THE INTERIOR...ESPECIALLY WITHIN VALLEYS...COLDER AIR
WILL LINGER.

/FORECASTER THINKING/

TEMPS/DEWPOINTS:

MAIN QUESTION IS WHERE COLD AIR DAMMING TAKE PLACE? FOLLOWED CLOSELY
WITH 2M MODEL TEMPS FROM THE NAM/WRF-ARW/WRF-NMM WHILE INCORPORATING
METNAM BIAS-CORRECTED GUIDANCE. CONSEQUENTIALLY...WITH EASTERLY
WINDS...THE SE COASTAL PLAIN SCOURS QUICKLY EARLY SUNDAY. WEST OF
THE I-495 BELTWAY AND I-95 CORRIDOR IT WILL LIKELY TAKE MORE TIME
FOR CONDITIONS TO WARM. WHILE A MAJORITY OF THE RGN WILL FLIRT
AROUND THE FREEZING MARK...LOCALES ACROSS THE HIGHER TERRAIN OF THE
BERKSHIRES AND WORCESTER HILLS...INCLUDING THE MID CT VLY.

PRECIPITATION CHANCES:

CONDUCTING A BLEND OF THE NAM/GFS/SREF...ONSET OF OVERRUNNING PRECIP
OCCURS IN THE EARLY MORNING HRS ON SUNDAY. AREAL COVERAGE OF LIKELY
POPS IS EXPECTED BY MIDDAY OVER MUCH OF THE FORECAST AREA WITH THE
HIGH CATEGORICAL POPS SUNDAY NIGHT INTO THE EARLY HALF OF MONDAY. IT
IS ANTICIPATED THAT HAZARDOUS DRIVING CONDITIONS WILL BE EXPERIENCED
FOR ROADWAYS ALONG AND N OF THE MASS PIKE ON SUNDAY AND INTO THE
MONDAY MORNING COMMUTE.

WEATHER:

FOLLOWING WITH A BLEND OF THICKNESSES FROM THE NAM/GFS/ECMWF/SREF
AND GOING WITH A TOP-DOWN METHODOLOGY...AM EXPECTING AN INITIAL
ONSET OF OVERSPREADING LIGHT SNOW FOR ALL AREAS SUNDAY MORNING
INTO MIDDAY. BY SUCH TIME THE WARMER EASTERLY FLOW WILL HAVE
LIKELY SCOURED COLDER AIR ACROSS THE SE COASTAL PLAIN AND POSSIBLY
ACROSS ALL OF RI INTO N CT /ALONG AND S OF THE MASS PIKE/...THOUGH
A WINTRY MIX MAY LINGER FOR AREAS N/W OF THE BOSTON METRO.
OTHERWISE...FROM LATE SUNDAY INTO MONDAY IT IS A SLOW PROCESS BY
WHICH DAMMING COLD AIR ACROSS THE INTERIOR IS GRADUALLY SCOURED
OUT. A WINTRY MIX OF SNOW...SLEET...AND FREEZING RAIN ALONG AND N
OF THE MASS PIKE GRADUALLY LIFTS NORTHWARD /QUICKLY MORESO FOR
LOCATIONS FURTHER E AND CLOSER TO THE E MA COASTLINE/.

HAZARDS:

/SNOW/ HEAVIER SNOW AMOUNTS ON THE ORDER OF 2 TO 4 INCHES WITH
ISOLATED AMOUNTS POSSIBLY UP TO 6 INCHES IS EXPECTED FOR S NH...WITH
A GENERAL 1 TO 2 INCHES ACROSS N MA.

/ICE/ ICE ACCUMULATIONS UP TO AROUND A TENTH OF AN INCH WILL BE
POSSIBLE FOR THE HIGHER TERRAIN OF THE BERKSHIRES AND WORCESTER
HILLS...INCLUDING THE MID CT VLY...WHERE COLD AIR WILL BE ENTRENCHED
LONGER AT THE SFC WITH WARMER AIR OVERRUNNING JUST ALOFT.

/OVERALL/ GENERAL HAZARDOUS WX WITH REDUCED VISIBILITIES AND
SLIPPERY CONDITIONS ON UNTREATED SURFACES. AS MENTIONED EARLIER...
HAZARDOUS DRIVING CONDITIONS ARE EXPECTED FOR THE PERIOD...
ESPECIALLY ALONG AND N OF THE MASS PIKE...AND W OF THE I-495/I-95
CORRIDOR.

CONCLUDING REMARKS:

UTILIZING CIPS ANALOG GUIDANCE FROM SAINT LOUIS UNIVERSITY...NEARLY
ALL OF THE ANALOGS EVENTS /15 IN TOTAL/ SIMILAR TO 15.0Z NAM
EXHIBITED A SUBSTANTIAL NUMBER OF FREEZING RAIN OBSERVATIONS ACROSS
SOUTHERN NEW ENGLAND. COLD AIR DAMMING IS DEFINITELY APPARENT IN
MANY OF THEM AS WELL...WITH THE SE COASTAL PLAIN SCOURED OUT
QUICKLY...WHILE THE INTERIOR REMAINS AT OR BELOW THE FREEZING MARK
FOR A LONG PERIOD OF TIME. THE BEST ANALOG EVENT IN THE LAST SEVERAL
RUNS CONTINUES TO BE CENTERED AROUND DECEMBER 9TH 1986 WHERE THE HEAVIEST SNOWS WERE ACROSS N NEW ENGLAND...HEAVIER PRECIP WAS S OF
NEW ENGLAND...AND A MAJORITY OF NEW ENGLAND SOME FREEZING RAIN AT
SOME POINT. IT IS UNCLEAR HOW MUCH ICE ACCRETION OCCURRED.

WITH THE POINTS RAISED ABOVE...FEEL THE EVENT IS MARGINAL AT THIS
TIME. DO NOT HAVE ENOUGH CONFIDENCE TO BELIEVE A WATCH IS WARRANTED
CRITERIA BEING 6" SNOW AND/OR 0.5 INCHES OF ICE ACCRETION. WHILE
WINTER WX ADVISORIES ARE LIKELY NEEDED FOR 3RD AND 4TH PERIODS BASED
ON THE LATEST FCST...WILL ALLOW LATER SHIFTS TO ADDRESS ACCORDINGLY
WITH UPDATED FCST INFORMATION AND PUBLISH AS THEY SEE FIT.

[LUCC]

NAM keeps trending drier for the front end snow; might have to turn those front end flakes to a front end flake (obviously not that little but still less than before, basically just flurries).

I can't believe I could actually end up having gone through November and 2/3rds of December in Albany with barely 1 accumulating snow event less than an inch (according to KALB; I measured a bit more with the 12/1 event). I'll be back in Albany after a while in NE NJ, but an early end to a non-winter and a late start to the next winter is really making the wait for snow much longer than it should be.

Wouldn't hold by breath for front-end snow for this one, if anything maybe a flurry or two, then grab your rain gear and be sure to check your sump pumps and clean your gutters for the next 2 storms.

[NorEaster07]

Heads up for messy morning commute if you're in the prone areas for this event.

http://www.facebook.com/US.NationalWeather....gov?ref=stream

"Confidence has increased for a winter weather event for Sunday into Monday. But uncertainty prevails concerning the remaining week thereafter as an active weather pattern is anticipated with a series of disturbances. Our latest thinking is below"

[jonjohnson]

I understand that this is a weather forum. I am upset that someone erased my post about yesterdays shooting. Coming from a person that has two small children and loves to talk weather with all of you, someone needs to grow up and maybe change a policy during extreme circumstances.


This post has been edited by jonjohnson: Dec 15 2012, 08:59 AM

[LUCC]

I understand that this is a weather forum. I am upset that someone erased my post about yesterdays shooting. Coming from a person that has two small children and loves to talk weather with all of you, someone needs to grow up and maybe change a policy during extreme circumstances.

I created a thread about the shooting in the proper 'everything else' section of the forums. Feel free to comment there.

This post has been edited by LUCC: Dec 15 2012, 09:13 AM

[NorEaster07]

OBS/Forecast thread for this event. http://forums.accuweather.com/index.php?showtopic=30282

[jdrenken]

I understand that this is a weather forum. I am upset that someone erased my post about yesterdays shooting. Coming from a person that has two small children and loves to talk weather with all of you, someone needs to grow up and maybe change a policy during extreme circumstances.

There are a few reasons why it was done...

1. This is a weather thread
2. Our guidelines state to stay on topic, your post would've taken away from it.
3. I also have children and felt heartbroken...but immediately went to the"Everything Else" thread knowing someone would have created a thread.