March 25-26 Potential Bomb Part II

[wolfie09]

Model diagnosis 

 

CYCLOGENESIS OVER THE NORTHEAST GULF OF MEXICO LATE MON...
...RAPIDLY INTENSIFYING SURFACE LOW OFF THE SOUTHEAST/MID-ATLANTIC
STATES BY TUES...

PREFERENCE: BLEND OF THE 12Z GFS/12Z GEM GLOBAL AND 00Z ECENS MEAN
CONFIDENCE: BELOW AVERAGE

THE UPR PATTERN BEGINS TO STRONGLY AMPLIFY ENTERING THE BEGINNING
OF NEXT WEEK WITH A LARGE POSITIVE HEIGHT ANOMALY SETTING UP
ACROSS THE WESTERN U.S. AND AN INCREASINGLY AMPLIFIED EASTERN U.S.
LONGWAVE TROUGH WHICH WILL BE ENHANCED BY THE DIGGING OF A
WELL-DEFINED SHORTWAVE TROUGH WHICH WILL RACE FROM THE DAKOTAS
SEWD INTO THE OH/TN VALLEYS BY EARLY TUES. THIS FEATURE IS OF
SIGNIFICANT IMPORTANCE AS IT ALLOWS FOR THE LARGER SCALE TROUGH
APPROACHING THE EAST COAST TO BEGIN TAKING ON A
NEGATIVE-TILT...AND IT WILL BE INTERACTING WITH A STRONG FRONTAL
ZONE OVER THE GULF OF MEXICO AND JUST OFFSHORE THE SOUTHEAST
COASTLINE. THE GUIDANCE SHOWS SIGNIFICANT CYCLOGENESIS
OCCURRING...WITH LOW PRESSURE INITIALLY DEVELOPING OVER THE NERN
GULF OF MEXICO AND THEN INTENSIFYING RAPIDLY OFF THE SOUTHEAST AND
MID-ATLANTIC COASTS ON TUES.

THE LATEST NAM DEPICTS AN ELONGATED BUT NEGATIVELY TILTED TROUGH
BY TUES STRETCHING FROM THE GRT LAKES REGION DOWN TO THE
MID-ATLANTIC STATES...BUT TENDS TO BE SLOWER WITH THE NRN PORTION
OF THE TROUGH AXIS. IT IS QUITE ENERGETIC WITH IS SHORTWAVE
DYNAMICS CROSSING THE OH VLY AND CNTRL APPALACHIANS AND SO MUCH SO
THAT IS PLACES A RATHER DOMINANT AREA OF LOW PRESSURE OVER THE OH
VLY...WHILE SUGGESTING CONSIDERABLY MORE MODEST CYCLOGENESIS OVER
THE NERN GULF OF MEXICO AND OFFSHORE THE EAST COAST BY COMPARISON.
THE 12Z GFS/12Z ECMWF/12Z GEM GLOBAL AND 12Z UKMET SHOW MUCH LESS
EMPHASIS ON AN OH VLY LOW AND SUPPORT CONSIDERABLE CYCLOGENESIS
JUST OFF THE SOUTHEAST COAST BY EARLY TUES...AND WITH RAPID
INTENSIFICATION TO OFFSHORE THE MID-ATLANTIC BY WED. THE 12Z GFS
IS QUICKER WITH THE LOW CENTER OFF THE EAST COAST COMPARED TO THE
12Z ECMWF...BUT WITH RESPECT TO TIMING THE 12Z UKMET AND 12Z GEM
GLOBAL ARE TRENDING TWD A SOMEWHAT FASTER SOLN LIKE THE GFS. THE
12Z UKMET IS THE DEEPEST SOLN OVERALL AND TRACKS ITS LOW CENTER
FARTHEST LEFT...WHICH HAS VIRTUALLY NO ENSEMBLE SUPPORT ATTM. THE
12Z GEM GLOBAL IS A LITTLE WEAKER THAN THE 12Z UKMET...FOLLOWED
THEN BY THE 12Z GFS AND 12Z ECMWF. IT WAS NOTICED THOUGH THAT THE
12Z GFS MAY BE SUFFERING FROM SOME DEGREE OF FEEDBACK NEAR THE
MID-ATLANTIC COAST ON TUES...WHICH HAS SOME IMPLICATIONS FOR ITS
QPF DISTRIBUTION...BUT ITS MASS FIELDS OTHERWISE SEEM REASONABLE.
THE STRONGEST MODEL CLUSTERING AT THIS POINT NOW TENDS TO FAVOR
THE 12Z GFS/12Z GEM GLOBAL AND 00Z ECENS MEAN...WITH THE
DETERMINISTIC ECMWF APPEARING TOO SLOW AND PROBABLY TOO FAR
SOUTHEAST OFF THE EAST COAST ON TUES. THE 12Z GEFS MEAN FAVORS THE
MORE PROGRESSIVE CAMP GFS-LED CAMP. THEREFORE...BASED ON THE
LATEST TRENDS AND MODEL CLUSTERING...WILL PREFER A BLEND OF THE
12Z GFS/12Z GEM GLOBAL AND 00Z ECENS MEAN...HOWEVER CONFIDENCE
WILL REMAIN LIMITED.

 

 

http://www.hpc.ncep.noaa.gov/discussions/pmdhmd.html

[ag3]

If it's snowing lightly or even moderate in the middle of the day it will not accumulate..come on,we have seen so many March and April storms..if there is heavy snow it's a different story..probably most of the snow that accumulates on the Euro is from late afternoon and night..it's March 25th

Euro had .55" of precip AFTER 8pm and only .09" before 8pm.

For KLGA.

[IsentropicLift]

Part of the problem here is that the mid-level centers are closing off just a tad late for our area. You can see here the hour 81 panel of the 12z GFS and the 850mb low just now closing off. You would want this to happen 6-12 hours sooner.

 

[famartin]

There were a few positives today at 12z. The GEFS GGEM EURO all sneak .5 into KNYC and .75 just to the east across long island.

 

The GGEM is only 0.3" at the park.

[Yanksfan]

A quote from a well respected Met:  "Yeah but even a monkey can figure out that the European model surface depiction is completely wrong. Sometimes people say that to be weenies, but I'm telling you it is more obvious than Marilyn Monroe having an affair with JFK."         Bobby Martrich Chief Meteorologist for EPAWA.

[IsentropicLift]

Still, if you follow the upper level wind structure on the GFS, this shows why it's tracking from near OBX to just SE of the benchmark. Despite the winds being more north to south the isobars are more SW to NE.

 

[famartin]

A quote from a well respected Met:  "Yeah but even a monkey can figure out that the European model surface depiction is completely wrong. Sometimes people say that to be weenies, but I'm telling you it is more obvious than Marilyn Monroe having an affair with JFK."         Bobby Martrich Chief Meteorologist for EPAWA.

I tend to agree that the Euro is a bit wacky, but FYI, he's not a met.  At least, not a degreed one.

[ag3]

The GGEM is only 0.3" at the park.

.

Yeah, but it's 10-15mm for Queens and Brooklyn.

.40"-.60"

[ag3]

.

Yeah, but it's 10-15mm for Queens and Brooklyn.

.40"-.60"

[weatherpruf]

I tend to agree that the Euro is a bit wacky, but FYI, he's not a met.  At least, not a degreed one.

Can you call yourself a meteorologist w/o a degree?

[Rjay]

Can you call yourself a meteorologist w/o a degree?

Lol apparently u can

[Yanksfan]

Still, if you follow the upper level wind structure on the GFS, this shows why it's tracking from near OBX to just SE of the benchmark. Despite the winds being more north to south the isobars are more SW to NE.

 

I read on another forum that a met stated that the 12z EURO and GFS both suffered from convective feedback issues, due to the new info starting to be picked up by the models, and the complex dynamics of the storm itself. He said the low should have developed closer to the coast and to toss them both. Ride the ensembles for now.

[Kevin Reilly]

I tend to agree that the Euro is a bit wacky, but FYI, he's not a met.  At least, not a degreed one.

Agreed .... Bobby is not a Met a nice guy though

[MJO812]

Hpc is saying feedback on the gfs and euro.

[Zelocita Weather]

Looks like model consensus today is 2-4" ne nj, 3-6" NYC and w li, 5-10" c and e li

[SnowGoose69]

I read on another forum that a met stated that the 12z EURO and GFS both suffered from convective feedback issues, due to the new info starting to be picked up by the models, and the complex dynamics of the storm itself. He said the low should have developed closer to the coast near OBX, and to toss them both. Ride the ensembles for now.

Not sure about the GFS but the Euro looked very funny

[+SNfreak21]

I don't know if anyone mentioned this, UKMET

[REDMK6GLI]

I don't know if anyone mentioned this, but UKMET destroys us, closed off H5

That looks amazing! Being the ukmet im hesitant to believe that, however the EURO suffering from what looks like from what i hears convective feedback the ensembles will be very important here folks

[Yanksfan]

I don't know if anyone mentioned this, but UKMET destroys us, closed off H5

I strongly feel if not for the strange surface depiction of the 12z Euro, it would of shown something very similar to this. Very eager to see the EURO ensembles. Got a good feeling its going to be west of the OP.

[GD0815]

I don't know if anyone mentioned this, UKMET

per the model discussion at the top of this page, dismissed as an outlier

[AvantHiatus]

Can you call yourself a meteorologist w/o a degree?

Can you disprove UFO's and Ghosts without a scientific study?

[IsentropicLift]

Very little change so far on the Euro ensemble mean. At 72 hours the spread is from the SC coast all the way to the Bahamas.

[IsentropicLift]

Euro ensemble mean is identical to the 00z ensemble mean run regarding track and a hair drier on the western side. Sub 980mb low well east of the BM.

[RU848789]

There were a few positives today at 12z. The GEFS GGEM EURO all sneak .5 into KNYC and .75 just to the east across long island.

I wouldn't have expect thermal profiles to be followed so closely 96 hours out but it's part of the process. A late march winter event looks to b shaping up from NYC east.

Not every storm is a blizzard although a foot of snow for someone on this board isn't out of the question as Suffolk County is close If the BL cooperates

We can settle that inside 48 hours. For now. There was NO shift east as the models held the 0z euro serve. Now here comes the but. Not a lot of room for error here. Between surface temps with lighter rates and the chance ths still goes east.

But as a whole. 12z didnt blow up . So you have to take it.

Finer details can be worked out but closer to the coast is prob where you Wana be for this one. Even if the BL looks marginal today.

 

 

Middlesex and Union are extremely close to NYC, so I wouldn't say that. I thjink most models show accumulating snow making it to eastern Jersey. Western Jersey is a different story.

Usually, with nor'easters, the precip gradient sets up from SE to NW (perpendicular to the NE path of the storm), which means that areas to the SW of NYC, along the NJ TPK, will tend to get very similar precip amounts as NYC (although as one heads NE along the I-95 line, precip will increase as the storm is intensiftying as it moves NE, so more precip is falling, in general).  Could be one of those storms with a pretty steep NW to SE gradient, i.e., 2" in Newton, 4" in Parsippany, 6" in Newark, and 8" in the Rockaways.  Could be a similar gradient line to the SE of that line, i.e., 1" in Stroudsburg (PA), 3" in Chester, 5" in Woodbridge and 7" in Asbury Park. 

 

And any precip that falls after about 5 pm will be largely unaffected by the indirect sunlight and perhaps the first 1/4" of snow will be melted in cooling down the ground to 32F and snow will accumulate easily after that, assuming air temps are around 32F and not 35-36F (sounds like they'll be around freezing by late in the afternoon).  We won't need a fast snowfall rate to overcome melting rates once the sun has lost its power after about 5 pm.  Earlier than that, as I discussed in an earlier post, melting rates increase with every hour towards midday, up to probably about 3/8"-1/2" per hour, meaning one needs at least moderate snowfall between maybe 11 am and 3 pm to get accumulation.  But it sounds like little precip will fall during the high melting rate daytime period.  Still need a better track to get more snow falling in the first place...

[MJO812]

The mean looks well west of the op.

[rcad1]

New England forum says the euro ensemble mean maybe a tad west of 0z!!

[weatherpruf]

Can you disprove UFO's and Ghosts without a scientific study?

Given the public interest, I really favor licensing for meteorologists. If you need licensing to cut hair or give a massage ( the real kind ) you ought to need one to forecast weather.

[PB GFI]

The GGEM is only 0.3" at the park.

Thought the Canadian ensembles were .5 at the park

[weatherpruf]

Usually, with nor'easters, the precip gradient sets up from SE to NW (perpendicular to the NE path of the storm), which means that areas to the SW of NYC, along the NJ TPK, will tend to get very similar precip amounts as NYC (although as one heads NE along the I-95 line, precip will increase as the storm is intensiftying as it moves NE, so more precip is falling, in general).  Could be one of those storms with a pretty steep NW to SE gradient, i.e., 2" in Newton, 4" in Parsippany, 6" in Newark, and 8" in the Rockaways.  Could be a similar gradient line to the SE of that line, i.e., 1" in Stroudsburg (PA), 3" in Chester, 5" in Woodbridge and 7" in Asbury Park. 

 

And any precip that falls after about 5 pm will be largely unaffected by the indirect sunlight and perhaps the first 1/4" of snow will be melted in cooling down the ground to 32F and snow will accumulate easily after that, assuming air temps are around 32F and not 35-36F (sounds like they'll be around freezing by late in the afternoon).  We won't need a fast snowfall rate to overcome melting rates once the sun has lost its power after about 5 pm.  Earlier than that, as I discussed in an earlier post, melting rates increase with every hour towards midday, up to probably about 3/8"-1/2" per hour, meaning one needs at least moderate snowfall between maybe 11 am and 3 pm to get accumulation.  But it sounds like little precip will fall during the high melting rate daytime period.  Still need a better track to get more snow falling in the first place...

Good discussion. I think we had 7 inches last March during the day that was down to 5 inches by the end of the storm, and mostly gone the next day. it was earlier in March too.

[MJO812]

Thought the Canadian ensembles were .5 at the park

.65