February 13-14 Potential Snowstorm II

[bluewave]

In this set up it is not that simple. The incoming kicker and westerly flow will only allow for so much of a westward trend. I actually tend to think that we will see a tick southeast over time, but yes it is possible this ends up a little more tucked in than the NAM.

Even the warmer models give us all a foot of snow...I don't think there should be any panic in here at all.

 

Interesting how close the euro and nam are with the two streams yet the nam is a little further east. All the important

stuff right now is still within the margin of error for a 72--84 forecast. Really small changes are going to make the

difference here.

[Superstorm93]

Where are individual members on Wxbell? I don't see them.

 

Go to Dr. Maues twitter feed. He posted a link to them if you are a WxBell subscriber. 

[IsentropicLift]

Late Thursday night?  According to the NAM, precipitation ends by around 7pm Thursday region wide and heavy precip is done by mid to late afternoon.

What are you looking at?

 

At 03z it's still snowing.

[IsentropicLift]

4k NAM has most areas snowing by 06z Thursday.

[Jersey Shore snow]

What are you looking at?

 

At 03z it's still snowing.

Negative...look at 06z Friday, there is no accumulated precipitation (or just a few hundredths) in the prior 6 hour period, so snow has stopped at 00Z Friday or 7pm on Thursday.

[NEG NAO]

don't see this too often - wide area down south and up the east coast of winter warnings

 

http://preview.weather.gov/

[Stormlover74]

don't see this too often - wide area down south and up the east coast of winter warnings

http://preview.weather.gov/

Wait til tomorrow.. The amount of pink and blue on that map is going to be staggering

[JetsPens87]

Negative...look at 06z Friday, there is no accumulated precipitation (or just a few hundredths) in the prior 6 hour period, so snow has stopped at 00Z Friday or 7pm on Thursday.

 

You are indeed correct

 

http://mag.ncep.noaa.gov/Image.php?fhr=078ℑ=data%2Fnam%2F18%2Fnam_namer_078_sim_radar.gif&model=nam&area=namer&param=sim_radar&group=Model+Guidance&imageSize=M

[sferic]

So us here, reading, analyzing and all of us snow lovers, does Wednesday's system appear to be he biggest snowmaker of the season so far?

[JetsPens87]

So us here, reading, analyzing and all of us snow lovers, does Wednesday's system appear to be he biggest snowmaker of the season so far?

 

Theres a snowstorm coming?

[JetsPens87]

What are you looking at?

 

At 03z it's still snowing.

 

On the NAM this looks to be about an 18 hour event give or take a few.

[PB GFI]

Theres a snowstorm coming?

What if game ,  The Northern SW gets better sampled tomorrow  and the changes are minor  , Do you think  being inside 48 hours one the changes are manageable as oppose to what they would do downstream say 120 hours plus . 

[Stormlover74]

Was surprised to see mt holly going with .1-.25" of ice as well

[JetsPens87]

What if game ,  The Northern SW gets better sampled tomorrow  and the changes are minor  , Do you think  being inside 48 hours one the changes are manageable as oppose to what they would do downstream say 120 hours plus . 

 

Yes, IMO the changes would be minor shifts in the track, I think OTS and inland runner are off the table. To me the sampling of the kicker will affect a few things...

 

1. How close to the coast does this come? I doubt huge jumps in the track at this point I feel the models are handling the southern stream pretty well

2. What does the precip shield look like? Exactly how much will that Gl disturbance press on the mid level field

3. How far away from the LP can dynamics reach? And where does the ccb setup?

4. Duration...Again a double edged sword with this GL disturbance but if it comes in faster then obviously an exit stage right will occur quicker but it will also prevent it from being too close to the coast

[PB GFI]

Yes, IMO the changes would be minor shifts in the track, I think OTS and inland runner are off the table. To me the sampling of the kicker will affect a few things...

 

1. How close to the coast does this come? I doubt huge jumps in the track at this point I feel the models are handling the southern stream pretty well

2. What does the precip shield look like? Exactly how much will that Gl disturbance press on the mid level field

3. How far away from the LP can dynamics reach? And where does the ccb setup?

4. Duration...Again a double edged sword with this GL disturbance but if it comes in faster then obviously an exit stage right will occur quicker but it will also prevent it from being too close to the coast

Right agree  at 120 hours , you`re foul pole to foul pole at 48 hours , you`re 2B to SS . Problem is when you get to the coastal plain , even that`s the whole forecast .

[tdp146]

Upton Summary: "P-type will be a challenging forecast" ... gee thanks

 

COMPLEX FORECAST WED NIGHT THROUGH THURSDAY.

BASED ON 12Z MODEL INTERROGATION...CHALLENGING FORECAST DUE TO
DIFFERENCES IN STRENGTH OF UPPER TROUGH/CLOSED LOW...AND THUS SFC
LOW PRESSURE TRACK. RAIN/SNOW LINE WILL BE THE ISSUE THIS FORECAST
PERIOD. ISOTHERMAL LAYER RIGHT AROUND 0C PER SOUNDINGS...AND A
DEGREE OR TWO EITHER WAY WILL MAKE A BIG DIFFERENCE. STRONG UPWARD
MOTION AND THE EFFECTS OF WET BULBING/EVAP COOLING WILL MAKE A BIG
DIFFERENCE AS WELL. OVERALL...A SFC LOW TRACK NEAR THE
BENCHMARK...EXCEPT ECMWF...WOULD BE A GOOD TRACK FOR PREDOMINATELY
SNOW...WITH HEAVIEST BANDS CUTTING THE CWA IN HALF. H8 LOW PASSING
JUST SOUTH IS ALSO INDICATIVE OF MAINLY SNOW.

LOW LEVEL THICKNESS PER NAM/GFS AND ECMWF THOUGH QUITE CLOSE WITH
PTYPE CONCERNS OVER A GOOD PORTION OF CSTL AREAS.

FOR NOW...BEST GUESS IS FOR SNOW TO COMMENCE WED NIGHT...BY AROUND
MIDNIGHT OR SO. SNOW ALL LOCATIONS WITH AN ACCUMULATION DURING THE
MORNING COMMUTE. THEN DURING THE DAY THURSDAY...PTYPE FORECAST WILL
BE A CHALLENGE. AGAIN...COASTAL LOCATIONS COULD SEE A RAIN/SNOW OR
SLEET MIX. NW ZONES MOST LIKELY REMAIN SNOW. SOMEWHERE IN THE
CWA...WARNING CRITERIA SNOW COULD BE REACHED...ALTHOUGH SREF PLUMES
AVERAGE IN THE ADVISORY RANGE...OR UNDER 6 INCHES MOST LOCALES.

HOWEVER...PTYPE ISSUES WILL BE PROBLEMATIC...THUS CONFIDENCE IN ANY
SNOW AMOUNT FORECASTS ARE LOW. TOO EARLY FOR ANY HEADLINES GIVEN THE
UNCERTAINTY.

[jm1220]

Right agree  at 120 hours , you`re foul pole to foul pole at 48 hours , you`re 2B to SS . Problem is when you get to the coastal plain , even that`s the whole forecast .

The warmest model gives us a huge snow thump before changing over. So even though a wrapped up Euro-like track eventually warms up, it also dynamically cools tremendously, and there might not be much to fall after temps get too warm. And that's the furthest west model by quite a bit.

[+SNfreak21]

Extreme comparison, but the 1993 Superstorm dropped around a foot with a front end thump in NYC with a coastal hugger track, if 850's stay cold and dynamics take over with a close track (like what 18z NAM is showing), it could be comparable to 1/27/2011

[PB GFI]

The 0 line get back through CNJ all the way N . Its a tic warmer than the OP .  But not as west as I thought it was gona be

[PB GFI]

The 0 line get back through CNJ all the way N . Its a tic warmer than the OP .  But not as west as I thought it was gona be

[Stormlover74]

Extreme comparison, but the 1993 Superstorm dropped around a foot with a front end thump in NYC with a coastal hugger track, if 850's stay cold and dynamics take over with a close track (like what 18z NAM is showing), it could be comparable to 1/27/2011

Yeah and the low tracked right over the Hudson river basically. Had slot of sleet before the dry slot/light rain and finally snow on the backside

[monmouthcounty11]

Mt. Holly's Updated Discussion:

 

WSW ISSUED FOR LOCATIONS WHERE CONFIDENCE LEVELS HAVE REACHED 50
PERCENT. SINCE THIS IS A 5TH PERIOD WATCH FOR OUR CWA AS IS AND WITH
UNCERTAINTIES TO NWWD EXTENT (ALSO GOING INTO A 6TH PERIOD) HELD
OFF ON A WATCH FOR PLACES FARTHER TO THE NORTH AND NORTHWEST.

THE GFS INITIALIZATION LOOKED BETTER OVERALL THAN THE WRF-NMMB AND
THE OPERATIONAL RUN HAS MOVED WESTWARD CLOSER TO CONSENSUS. OTHERWISE
WE ARE SEEING SIMILAR MODELING OUTCOMES TO THE LAST COUPLE OF DAYS
WITH THE ECMWF ON THE WEST SIDE OF THE SOLUTION ENVELOPE. ONE
PIECE OF THE PUZZLE IS NOW IN CALIFORNIA (AND SLIGHTLY STRONGER
THAN INITIALIZED), WITH ANOTHER PIECE OF THE PUZZLE STILL IN THE
PACIFIC. ITS DP/DT ALSO LOOKS STRONGER. WHILE THERE ARE TRACK
DIFFERENCES. THERMALLY ALL OF THE MODELS (18Z WRF NOT) ARE SHOWING
SOME PTYPE ISSUES FROM AROUND THE INTERSTATE 95 CORRIDOR
SOUTHEASTWARD. CONVECTION IN THE GULF OF MEXICO AND OFFSHORE ARE
GOING TO CAUSE MODELING WOES WELL INTO WEDNESDAY AND WE STILL HAVE
TO WAIT FOR THE NORTHERN STREAM SHORT WAVE TO COME ONSHORE. SO
PLEASE DONT GET TOO ATTACHED TO THE PREDICTED SNOW AND ICE AMOUNTS
AS WHILE WE ARE FAIRLY CERTAIN ABOUT WINTER STORM CRITERIA BEING
MET, THE COMBINATION OF SNOW, SLEET AND FREEZING RAIN ARE FAR FROM
ETCHED IN STONE.

LONG TERM STARTING QUIET ENOUGH OM TUESDAY NIGHT WITH HIGH PRESSURE
BUILDING NORTH OF THE AREA. BETTER CHANCES OF WINDS GOING L/V NORTH
THAN SOUTH AND REASON (ALSO WITH MORE SNOW COVER) OF GOING BELOW
STAT GUIDANCE THERE.

CLOUDS WILL INCREASE ON WEDNESDAY AS THE SYSTEM STARTS TO GET
ORGANIZED AND MOVE CLOSER TO OUR AREA. AIR MASS POTENTIAL WOULD
SUPPORT SLIGHTLY HIGHER MAXES THAN WE HAVE POSTED, BUT SHAVED A FEW
DEGREES OFF BECAUSE OF THE CLOUDINESS.

A JUXTAPOSITION ON WEDNESDAY NIGHT AS THE SYSTEM APPEARS TO BE
INITIALIZING DEEPER (THUS SLOWER?) BUT WAA INDUCED PCPN LIKES TO
START FASTER. WE HAVE OPTED TO BALANCE THE TWO OPPOSING TENDENCIES
AND STILL HAVE PCPN ARRIVE ON THE GROUND STARTING WEDNESDAY EVENING.
INITIALLY EVERYONE WILL BE COLD ENOUGH FOR SNOW, BUT BY LATE AT
NIGHT WARM AIR MOVING IN ALOFT SHOULD START CHANGING THE SNOW OVER
TO SLEET OR RAIN FAR SOUTHEAST. THE GFS CONFINES THE STRONGEST FGEN
FORCING, ISENTROPIC LIFT AND WAA SOUTHEAST. WE WERE SLIGHTLY MORE
LIBERAL WITH QPF THAN THAT EXPECTING A NWWD ADJUSTMENT. THIS WOULD
ALSO MEAN A STRONG FRONT END SNOW BEFORE EVEN A THOUGHT OF A
CHANGEOVER CAN BE ENTERTAINED. PART OF THIS THINKING TO IS BECAUSE
OF THE IDEAL LOCATION OF THE ENTRANCE REGION OF THE 250MB JET AT
THAT TIME.

THEN ON THURSDAY ALL THE MODELS KEEP SNOW AS A PTYPE FROM THE FAR
NORTHWEST PHILADELPHIA SUBURBS THROUGH THE POCONOS AND NORTHWEST NJ.
UNCERTAINTY IN THESE AREAS IS ON PCPN AMOUNTS. FROM AROUND THE
INTERSTATE 95 CORRIDOR SOUTHEASTWARD WHETHER ITS AT 850MB OR 925MB,
ALL THE MODELS ARE FORECASTING A AT OR ABOVE FREEZING WARM LAYER TO
COME IN AT 850MB (LIKE THE EC) OR 925MB (LIKE THE 12Z WRF-NMMB).
THEY ARE ALSO RAISING TEMPERATURES TO OR ABOVE FREEZING. THIS WILL
BE ANOTHER BALANCING ACT AS THE POSITION OF THE SFC HIGH IS
FORECAST TO NOT BE THE BEST TO MAINTAIN SNOW AS A PTYPE NEAR THE
COAST. THIS WILL BE COUNTERBALANCED BY THE INTENSIFICATION OF
THE SFC LOW ITSELF. WE HAVE FOUND A COUPLE OF ANALOGOUS EVENTS
AND THEY HAVE PRODUCED ONE FOOT SNOWS WI CWA. WE DID NOT INCLUDE
THE POSSIBILITY, BUT THE FCST EPV DOES GO NEGATIVE AS THE DRY SLOT
APPROACHES THE ERN PART OF OUR CWA THURSDAY MORNING. THUNDERSNOW
WOULD NOT BE OUT OF THE QUESTION.

THE ECMWF IS MOST BULLISH WITH THE DEFORMATION ZONE/WRAP AROUND PCPN
ON THURSDAY NIGHT. FOR NOW WE LEANED TOWARD OTHER MODELING CONSENSUS
AS FOR TIMING (FASTER ENDING) AND QPF AMOUNTS. A CHANGE BACK TO
SNOW APPEARS LIKELY FOR MOST OF OUR CWA.

[IsentropicLift]

The 0 line get back through CNJ all the way N . Its a tic warmer than the OP .  But not as west as I thought it was gona be

How many feet of snow does it spit out for the interior?

[David-LI]

Why couldn't this be 24 hours out instead of 60 ....Euro with its more NW track should likely win, though the NAM 700mb makes a lot of sense with how it is modeled. 

 

Upton already said the euro is the outlier. Going with a blend of gfs, nam, ukie

 

"EASTERN U.S. CYCLONE AND WINTER STORM...

PREFERENCE: BLEND OF 12Z NAM/GFS/UKMET

CONFIDENCE: AVERAGE"

[PB GFI]

How many feet of snow does it spit out for the interior?

Don't have precip , but think this you`re storm

 

But If the UKIE is right , no one escapes

[nyblizz44]

Yeah and the low tracked right over the Hudson river basically. Had slot of sleet before the dry slot/light rain and finally snow on the backside

the snow on backside which was forcast to be 2-4 or 3-6 depending on location never happened in queens - merely a few flurries. with very few exceptions never count on backend snow arond locations from knyc / east

[sferic]

What's nice if not great is that it is super cold between now and Wednesday night with fantastic snowcover. By Thursday it will look awesome. What is on the potential drawing boards for after Thursday?

[sferic]

Are the winds with this one, Any potential blizzard like conditions?

[jm1220]

the snow on backside which was forcast to be 2-4 or 3-6 depending on location never happened in queens - merely a few flurries. with very few exceptions never count on backend snow arond locations from knyc / east

The 500mb low during the Superstorm never closed off I believe. You need the closed off 500mb low to have snow due west or SW of the surface low. That will cause air to flow around and down the west side of the low in the mid levels, where snow forms.

[DiehardFF]

^{1.1 QPF from PHL to NYC on the ECM ENS.}