Wednesday into Turkey Day Storm

[WhiteoutMD]

Thanks!

 

My personal guess based on all the data is Light rain starts in the city pre-dawn like 3-5am, probably some sleet/snow/rain mix at 7am-8am, but the city goes over to mostly rain through rest of day with sleet/snow mixed in at times...

 

I think Philly sees <1" of snow, I am not feeling good about this event...

 

However, 15-20 miles N and W? Could be a nice wet snowstorm. 

[ChescoWx]

My latest forecast for NW Chesco at 685 ft asl with the Wxsim program just shows rain with a little mixing for a couple hours with no accumulation - total precip at 0.66"

[Birds~69]

Ch6/Accu-Weather noontime broadcast maps (Euro and GFS) current prediction:

 

 

[MJO812]

Euro is further east

[DiehardFF]

I say the euro gives NW I-95 6"-8" of paste.

[Blizzard-on-GFS]

Ch6/Accu-Weather noontime broadcast maps (Euro and GFS) current prediction:

Those graphics are highly inaccurate.

[Birds~69]

Those graphics are highly inaccurate.

 

Yeah...just throwing it out there.

[Heisy]

Those graphics are highly inaccurate.

 

 I disagree, they seem pretty fair imo

[Blizzard-on-GFS]

I disagree, they seem pretty fair imo

The GFS shows at least an inch for I-95.

[JCT777]

I do think there will be at least a little snow accumulation from the city on north/west.  It'll come down to precip rates determining whether it's a light mix / rain or whether it's accumulating wet snow falling.

[TeleConnectSnow]

In my honest opinion, areas in the immediate philly area will have a rough time this storm. I think they will see snow but hard for any accumulations, I might not have all the science behind my reasoning, but I have been present in some big time storms in the past 20 years, I truly believe models are going to shift back west. That shortwave is the key to this setup. I think the models aren't getting a grasp on that piece of energy yet.

[Heisy]

The GFS shows at least an inch for I-95.

 

and the map shows I-95 C-1", you're issue?

[RedSky]

Wunderground snow maps have 7-11" in SEPA from SE to NW. I think Berks has the best shot at 10" and Philly comes in lower more like 3"

[Lady Di]

I hate these I-95 rain\snow line storms.  9 times out of 10 in my location (extreme se PA near DE line) we are too warm at the surface starting as rain and the energy off the coast gets well past us during changeover lowering rates.  Expecting some flakes to a coating here.  Looking forward to an all frozen storm to track in the near future. 

[hazwoper]

Mt Holly watch forth coming

 

.LONG TERM /TUESDAY THROUGH SUNDAY/...
DRAFT WITH ADJUSTMENTS AT 330 PM WHENEVER THE HIGH RES ECMWF ARRIVES.

**WINTER STORM/EVENT OF WET SNOW AT HAND E PA AND NW NJ. WATCHES
WILL BE EXPANDED TO JUST NW OF THE I-95 INTERSTATE CORRIDOR**
 

THE STORM...

OUR RECOMMENDATION: TO REACH YOUR HOLIDAY DESTINATION ON TIME WITH
PROBABLY A MINIMUM OF WEATHER RELATED TRAVEL DELAYS...AND ESPECIALLY
TRAVELING WEST OF I-95 INTO NORTHWEST NJ...EASTERN PA...TRAVEL SHOULD
BE COMPLETED BY 10 AM WEDNESDAY.

THE WATCH WILL BE EXPANDED SOUTHWARD TO JUST NW OF I-95 IN THE 330 PM.
ANY FURTHER CHANGE AFTER THIS WRITING IS RELATED TO A SUBSTANTIAL
CHANGE IN THE EVENTUAL 12Z ECMWF RECEIPT.

TUESDAY NIGHT...LEFTOVER WARMTH AND IT APPEARS THE LEADING EDGE OF
THE PCPN SHIELD WILL BEGIN AS RAIN MOST OF THE AREA EXCEPT WELL
WEST OF I-95. NO ACCUMULATION ANTICIPATED. LIGHT WEST WIND BECOMING
N-NE TOWARD MORNING.

WEDNESDAY THROUGH MIDNIGHT WEDNESDAY EVENING...

WEST OF I-95...MAINLY WHERE SOME BANDING AND ASSOCIATED SNOWFALL
RATE ENHANCEMENT EXPECTED ALONG THE SE EDGE OF THE COMMA HEAD (THERMAL
AXIS OF PIVA AND FGEN). ACCUMULATION HERE MAY BE MORE ON THE ORDER
OF 12 TO 1? FIVE PLUS TOTALS...ESPECIALLY ELEVATIONS WHERE 10
INCHES MAY ACCUMULATE ABOVE 1000 FT (POCONOS AND SUSSEX COUNTY NJ).

I-95 CORRIDOR RAIN MIXING WITH OR CHANGING TO WET SNOW AT TIMES OR
POSSIBLY REMAINING AS SNOW DURING THE AFTERNOON. WHILE QPF IS
GREATER HERE...ACCUMULATION SHOULD BE NOT BE GREATER THAN 10 TO
1 RATIO. SLOPPY WET SNOW THAT COULD CLING TO TREES AND WIRES AND
OBSCURE ROAD SIGNS DURING THE AFTERNOON EVENING IN A 32-33F SURFACE
TEMPERATURE ENVIRONMENT. IF 6 INCHES OF WET SNOW WERE TO OCCUR...THE
RISK OF BROKEN TREE LIMBS SHOULD INCREASE CONSIDERABLY BUT ONLY
WHERE 6 INCHES OCCURS. TOTALS UNKNOWN BUT SUSPECT 0.5 TO 4 INCH
AMOUNTS. FINE LINE ON WHERE IT WILL SNOW BUT TOO MUCH INFO ATTM TO
WARRANT A WATCH PER INTERNAL COLLABORATION.


COAST: RAIN POSSIBLY ENDING AS SNOW WEDNESDAY EVENING. TOTALS NIL TO
2 INCHES? NO ACCUMULATIONS DURING THE DAY AS PER THE WATER TEMPERATURE
STILL IN THE MID 50S, THE ONSHORE FLOW AND PROXIMITY OF THE WARMING
ALOFT NEAR THE SURFACE LOW AND EAST OF THE VORT PATH SHOULD KEEP
THEM WELL ABOVE FREEZING THROUGH OUT THE DAY. THE CAVEAT TO ALL OF
THIS IS THAT THE LOCATION OF THE RAIN/SNOW TRANSITION AND EVEN SNOW
RATIOS IS VERY MUCH DEPENDENT ON THE TEMPERATURE PROFILE. THERE
IS STILL MODEL DISAGREEMENT, SO SNOW AMOUNTS REMAIN UNCERTAIN FROM
I95 EASTWARD REMAIN FAR FROM CERTAIN.

THE COAST SHOULD CHANGE TO SNOW OR FLURRIES WEDNESDAY EVENING BEFORE
ENDING WHEN A SLIGHT ACCUMULATION COULD OCCUR.

PRECIPITATION EVERYWHERE MODERATE TO HEAVY FOR A TIME DURING THE
DAY WITH TAIL END SNOW IN EASTERN PA AND NW NJ POSSIBLY STILL
MODERATE DURING THE EVENING.

 

[Morch Madness]

Yes please

 

[KamuSnow]

Yes please

 

 

 

There you go! Getting better for those near the fall line...

[hazwoper]

Yes please

 

 

 

Back to pretty much what they had yesterday.  This should be what we see at this point.

[jimmosk]

What the grep does "ACCUMULATION HERE MAY BE MORE ON THE ORDER OF 12 TO 1? FIVE PLUS TOTALS." mean?

 

Ah, wait, I get it - they don't mean accumulation of 12 inches, they mean 12:1 ratios, with total accums of five inches plus.

 

As Emily Latella would say... Never mind!

[KamuSnow]

I hate these I-95 rain\snow line storms.  9 times out of 10 in my location (extreme se PA near DE line) we are too warm at the surface starting as rain and the energy off the coast gets well past us during changeover lowering rates.  Expecting some flakes to a coating here.  Looking forward to an all frozen storm to track in the near future. 

 

I know what you mean, but I'm 50/50 optimistic for my location (as far as more snow vs. more rain), and I think you'll do better being 12 miles to the west. I don't think there will be as much of a north/south difference at our latitude, more WNW to ESE. You may be closer to the "safe zone". We shall see!

[hazwoper]

What the grep does "ACCUMULATION HERE MAY BE MORE ON THE ORDER OF 12 TO 1? FIVE PLUS TOTALS." mean?

 

I am assuming they menat to add some (  ) in there so it would read something like the following as the comma head is where you'd expect the best snow growth and thus higher ratios (but I am just making a guess):

 

ACCUMULATION HERE MAY BE MORE ON THE ORDER

OF (12 TO 1) FIVE PLUS TOTALS...ESPECIALLY ELEVATIONS WHERE 10

INCHES MAY ACCUMULATE ABOVE 1000 FT (POCONOS AND SUSSEX COUNTY NJ).

[Heisy]

Can't I just imagine that it is January and the other levels of the atmosphere don't matter...please?!

 

 

lol

[Fields27]

Winter storm watch up!

 

Urgent - Winter Weather message
National Weather Service Mount Holly NJ
331 PM EST Mon Nov 24 2014

Hunterdon-Berks-Lehigh-Northampton-Western Chester- Western Montgomery-upper Bucks- including the cities of...Flemington...Reading...Allentown... Bethlehem...Easton...Honey Brook...Oxford...Collegeville... Pottstown...Chalfont...Perkasie 331 PM EST Mon Nov 24 2014

...Winter Storm Watch in effect from Wednesday morning through late Wednesday night...

The National Weather Service in Mount Holly has issued a Winter Storm Watch...Which is in effect from Wednesday morning through late Wednesday night.

* Locations...A Small portion of Northern New Jersey...The Lehigh Valley Down into Southeast Pennsylvania.

* Hazard types...Heavy Snow. 

* Snow accumulations...4 to 8 inches.

* Timing...Precipitation...Mostly Rain...Will begin near Dawn Wednesday. It will probably quickly transition to wet Snow by Mid or late morning and continue moderate to heavy at times during the afternoon before ending during the late evening Wednesday.

* Temperatures...Above freezing Early in the Day falling to freezing during the Snow and then falling Only a Few degrees below freezing after the Snow ends Wednesday night.

* Impacts...Anyone with Holiday travel plans Wednesday should Complete travel by Mid morning Wednesday to avoid any significant Weather related delays. Wet Snow May Cover road signs. There is a Small Chance wet Snow could knock down a Few tree limbs if it accumulates more than 4 inches on branches and wires. This would Result in a Few Power outages.

Precautionary/preparedness actions...

A Winter Storm Watch Means there is a potential for significant Snow...Sleet...Or Ice accumulations that May Impact travel. Continue to Monitor the latest forecasts.
A2

[Coltsfan1217]

Has anyone seen the euro ensembles? Is it me or are they showing a lot more cold air in place than the OP Euro?

[JCT777]

71 today and a forecast from Mt. Holly for 4 to 6 inches of snow starting in about 42 hours.  Fun stuff!

[Heisy]

I found this interesting, but the NAM-Hi res has a deathband over SE PA, and you can kind of see the dynamic cooling from it based off the 925mb temps....at least I think you can...

 

[Birds~69]

Glenn's map from the 6pm broadcast. Think it may be a little high? Maybe change 3-5 to 2-4...5-8 to 4-6....who knows?

 

 

[noctilucent]

Glenn's map from the 6pm broadcast. Think it may be a little high? Maybe change 3-5 to 2-4...5-8 to 4-6....who knows?

 

He may be accounting for unpaved surfaces.   I expect that my sun-exposed driveway will hold only about half or less of the accumulation on unpaved surfaces.    

 

I tossed out my 10-year-old snow shovel at the end of last season, and bought a new one today on the way home from work.

Then I saw the Winter Storm watch up and thought I might need to break out the snowblower, but whatever falls on paved surfaces is likely to be the slimiest muck I will ever see!   Plus we will be only about 48 hours removed from near-70 degree temps.

 

Gonna be quite the roller-coaster ride.

[Birds~69]

He may be accounting for unpaved surfaces.   I expect that my sun-exposed driveway will hold only about half or less of the accumulation on unpaved surfaces.    

 

I tossed out my 10-year-old snow shovel at the end of last season, and bought a new one today on the way home from work.

Then I saw the Winter Storm watch up and thought I might need to break out the snowblower, but whatever falls on paved surfaces is likely to be the slimiest muck I will ever see!   Plus we will be only about 48 hours removed from near-70 degree temps.

 

Gonna be quite the roller-coaster ride.

 

Oh yeah he mentioned that which I expected. Lots of variables...changeover time...precip intensity...track of storm etc.

[Birds~69]

I believe he is accounting for proper measuring techniques (use of snowboard). METs don't make forecasts for snowfall based on what accumulates on asphalt or grass

 

This is probably true but he has to "dumb it down" for the casual viewer and how it affects them especially on one of the busiest travel days of the year. Basically saying the totals will be in that range but a certain amount won't be on paved surfaces. (roads) and will accumulate on trees, grassy and unpaved surfaces.