"MEGA -- STORM"

[RIROCKHOUND]

From Accuweather.. one of the few with the cajones to post long range predictions...

[striperman36]

Wife has surgery in hartford tuesday, not a good travel for there.

NWS is saying models have the storm tracking east of the CWA and we would only have a light covering in front and perhaps a wrap around comma after, this looks like the comma could be pretty cold, 1" or less of moisture 10-15 X factor for snow.


Weatherunderground is dead on it too.

he old stalled cold frontal boundary provides a ribbon of strengthening baroclincy allowing for the surface low to intensify as it reaches our latitude. Intense deformation band of snow in the cold conveyor flow develops on the backside of the low on Tuesday and Tuesday night bringing significant amounts of snow across the Northeast within 100-150 miles of the coast down to the northern Mid-Atlantic and extending north into much of New England. As the mid-level low pressure features aloft approaches the coast secondary development occurs later Tuesday night as the primary shears out keeping snow over the region until Wednesday morning. This solution has the potential to drop a foot or more of snow across a wide region of the Northeast. QPF’s range from three-quarters of an inch to an inch and a half in both the NAM/GFS. This snow would also be rather fluffy as cold air gradually incorporates itself into the circulation of the storm system from the north. Snow ratios should range from 12-16:1 or higher near the end of the storm as max omega intersects a moist snow growth region in the deformation axis. The SREF plumes also have decent support for this scenario as the SREF mean precip over the Northeast ranges from a half inch to an inch in the above mentioned areas with many plume diagrams showing an inch or more of QPF.


So not a lot of moisture - QPF but a lot of snow - 12-16:1

[striperman36]

Here's the weatherman's dilemma
No consensus in the models across the board -
US (GFS/NAM) shows the Mega-Storm
European (UKMET) shows it going way east
Canadian models(GGEM, ECMWF) are in the middle

This winter the GFS has been pretty accurate, but with the variance, even in models from run to run has almost everyone just shrugging

In the middle of the very snowy American models and the out-to-sea UKMET lies the Canadian GGEM and the ECMWF. These models have trended west over their last couple of runs but not as extreme as the GFS/NAM or SREF’s. They take low pressure about 100-150 miles further offshore than the American models with some light to moderate QPF, generally under a half inch, in the deformation banding on the backside of the storm. This would still give areas within 50-75 miles of the coast a 2-6” snowfall, roughly a half to a third of the output of the GFS/NAM.

[Pete_G]

The National Weather Service admits they don't have a clue about the storm at this point. Sorry about the caps, that's how they post these discussions:

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...

MONDAY NIGHT THROUGH WEDNESDAY...

THE MODELS CONTINUE TO STRUGGLE AND FLIP FLOP ON A POTENTIAL STORM
SYSTEM FOR SOUTHERN NEW ENGLAND. THEY ARE HAVING A TOUGH TIME
FIGURING OUT HOW MUCH TROUGH AMPLIFICATION WILL OCCUR WITH NORTHERN
STREAM ENERGY. THEY ALSO ARE NOT SURE ON WHICH PIECE OF ENERGY THEY
WANT TO CAPTURE AND HOW CLOSE TO THE COAST THE SYSTEM WILL TRACK.

THERE IS NO POINT IN GOING INTO SPECIFIC DETAILS OF EACH
MODEL...SINCE MOST HAVE NOT SHOWN MUCH CONSISTENCY AND HAVE BEEN
VERY UNSTABLE FROM RUN TO RUN. THE ONLY THING WE CAN SAY IS THAT
SINCE THE MODELS GOT AWAY FROM THE INLAND BOMB SCENARIO...THE ECMWF
HAS BEEN THE MOST CONSISTENT AND STABLE WITH A LESS AMPLIFIED
SOLUTION AND A FURTHER EAST TRACK. THE ECMWF HAS BEEN FAR SUPERIOR
IN MOST OF THESE SITUATIONS THE LAST FEW YEARS...SO UNTIL WE SEE IT
GO FOR A MAJOR WINTER STORM WE WILL KEEP THE FORECAST ON THE MORE
CONSERVATIVE SIDE. HOWEVER...THE 00Z ECMWF MODEL DID TREND A BIT
FURTHER WEST FROM ITS LAST FEW RUNS...SO THIS WILL HAVE TO BE
CLOSELY WATCHED.

ALL IN ALL...THE AMERICAN MODELS AND THEIR ENSEMBLES ARE CLOSER TO
THE COAST/STRONGER AND HAVE A MUCH BIGGER IMPACT THAN THE INTERNATIONAL
MODELS. LIKE WE SAID BEFORE...WE WILL LEAN TOWARDS THE ECMWF
SOLUTION BASED ON ITS TRACK RECORD...BUT ALSO WILL TAKE INTO ACCOUNT
SOME OF THE AMERICAN MODELS INTO OUR FORECAST. REGARDLESS...ALL THE
MODELS DO HAVE A CLASSIC INVERTED TROUGH SETUP...SO WE FEEL THAT WE
WILL GET AT LEAST SOME SNOW PULLED BACK INTO THE REGION.
THEREFORE...RIGHT NOW WE FEEL THE BEST FORECAST IS FOR A LIGHT TO
MODERATE SNOWFALL ACROSS MUCH OF THE REGION SOMETIME LATE MONDAY
NIGHT INTO EARLY WEDNESDAY. THIS IS NOT SET IN STONE THOUGH AND
SINCE THE MODELS HAVE BEEN SO UNSTABLE THE LAST FEW DAYS...WE DO NOT
WANT TO RULE ANYTHING OUT. THIS INCLUDES THE MORE INTENSE AMERICAN
MODEL SOLUTIONS WHICH WOULD BRING A SIGNIFICANT SNOWFALL TO MUCH OF
THE REGION.

ONE OF THE INTERESTING THINGS ABOUT THIS FORECAST IS THE AMERICAN
MODELS ARE CLUSTERED ON ONE SIDE WITH THE INTERNATIONAL MODELS ON
THE OPPOSITE SIDE. THE AMERICAN MODELS HAVE BETTER RESOLUTION...BUT
THAT DOES NOT MEAN THEY ARE CORRECT. WE WILL JUST HAVE TO WAIT AND
SEE HOW THINGS PAN OUT AND HOPE THEY COME INTO BETTER AGREEMENT OVER
THE NEXT 24 HOURS. RIGHT NOW WE WILL LEAN TOWARDS THE ECMWF...BUT
KEEP ALL OPTIONS OPEN.

WILL RUN WITH CHANCE POPS MONDAY NIGHT...AND LIKELY POPS TUESDAY
AND TUESDAY NIGHT. WILL PROBABLY HOLD ONTO SOME CHANCE POPS ON
WEDNESDAY MORNING WITH UPPER LEVEL TROUGH STILL TO OUR WEST. IF THE
MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS WILL WANT TO
UPGRADE TO CATEGORICAL POPS. EVEN THOUGH WE THINK WE WILL AT LEAST
GET SOME PRECIPITATION...THE MODELS ARE ALSO STRUGGLING WITH TIMING
SO WILL KEEP THINGS IN THE LIKELY RANGE.

AS FOR PRECIPITATION TYPE...THINK IT WILL BE MAINLY SNOW OVER MOST
OF THE REGION. HOWEVER...SOUTHEAST OF THE I-95 CORRIDOR THERE WILL
LIKELY BE SOME BOUNDARY LAYER ISSUES AT TIMES RESULTING IN SOME
LIQUID PRECIPITATION. IF THE DEEPER FURTHER WEST SOLUTIONS
VERIFY...BOUNDARY LAYER ISSUES COULD PUSH EVEN FURTHER NORTHWEST.
THIS FURTHER COMPLICATES AN ALREADY EXTREMELY CHALLENGING FORECAST!

REGARDLESS OF WHAT HAPPENS SOME VERY COLD AIR WILL LIKELY MOVE INTO
THE REGION ON WEDNESDAY BEHIND THE DEPARTING STORM SYSTEM.
DEPENDING ON JUST HOW INTENSE THE STORM BECOMES WILL DETERMINE JUST
HOW COLD IT GETS...BUT TEMPERATURES WILL LIKELY BE SIGNIFICANTLY
BELOW NORMAL.

[Raven]

what? no mega storm...?
,,,,,,,,, ,,,,,,

[striperman36]

MAybe maybe not

[striperman36]

Originally Posted by RIROCKHOUND

From Accuweather.. one of the few with the cajones to post long range predictions...

They're punting now too.
"One wild card that the atmosphere could still play is this: a lack of moisture. Some potential exists that the needed moisture would veer away to the east leaving the region with a relatively minor storm. This factor will be among several that AccuWeather.com will continue to follow keenly."