Snowstorm of the season NE Megalopolis?

[Ed Mahmoud]

12Z GFS seems to be leaning in that direction...


The Ohio Valley got their snow storm of the season, maybe its NYC's turn. And, on a Sunday, could maximize school closure potential.

[jinftl]

NWS mentions possibly a rain event in the northeast on sunday with temps around 50...as of right now, sunday is forecasted sunny and around 50 in the big cities...nothing to sound the alarms with a rogue model yet..esp calling it 'snowstorm of the season'

[Ed Mahmoud]

NWS mentions possibly a rain event in the northeast on sunday with temps around 50...as of right now, sunday is forecasted sunny and around 50 in the big cities...nothing to sound the alarms with a rogue model yet..esp calling it 'snowstorm of the season'

I'm not the NWS, nor even a pro-met, so I doubt my calling it the snowstorm of the season will cause that much panic or alarm...

[Ed Mahmoud]

The 6Z DGEX would seem to suggest NYC is mostly rain, with possibly a short period of heavy snow at the end, but BOS might quickly change to snow, and get a good accumulation, and check out how the surface low really cranks.



Granted, the Canadian is way offshore...

[jinftl]

Don't sell your posts short...an attention grabbing headline like that for tens of millions is enough to make an impression...not a cause of hysteria, but an impression nonetheless...

I'm not the NWS, nor even a pro-met, so I doubt my calling it the snowstorm of the season will cause that much panic or alarm...

[jinftl]

Current forecast think from NWS New York for same time period...

NWS Forecast for: New York NY
Issued by: National Weather Service New York City/Upton, NY
Last Update: 11:03 am EDT Mar 10, 2008
------------------------------------------------------------------------
Friday: A chance of rain. Cloudy, with a high near 53. Chance of precipitation is 40%.

Friday Night: A chance of rain. Cloudy, with a low around 36. Chance of precipitation is 50%.

Saturday: A chance of rain. Partly cloudy, with a high near 50. Chance of precipitation is 30%.

Saturday Night: Partly cloudy, with a low around 36.

Sunday: Mostly sunny, with a high near 48.

Sunday Night: Partly cloudy, with a low around 29.

Monday: Sunny, with a high near 49.

[Ed Mahmoud]

Part of the fun is out-guessing the NWS.

Looks like only the GFS and DGEX (which is fed GFS data) sees this now, the Euro is also offshore.

[jinftl]

i hear ya...like they say, throw enough darts and eventually you a hit bullseye...could be the 12Z GFS's mantra!

Part of the fun is out-guessing the NWS.

Looks like only the GFS and DGEX (which is fed GFS data) sees this now, the Euro is also offshore.

[Ed Mahmoud]

NWS BOX (Boston-Taunton) mildly interested. snippet

MODEL SOLUTIONS AGREE ON A STORM FOR THE WEEKEND...AND SIMILAR TIMING FOR SATURDAY NIGHT AND SUNDAY. BUT DIFFERENCES CONTINUE ONCE THE
STORM CENTER MOVES OFFSHORE WITH THE ECMWF FARTHEST SOUTH AND THE
OPERATIONAL GFS WEST OF THE GFS ENSEMBLE MEAN. THE ECMWF ALSO HOLDS
MOST OF THE PRECIP OFFSHORE. WE WILL INSTEAD GO WITH THE GFS
PLACEMENT...WHICH BRINGS 2 TO 4 TENTHS OF WATER EQUIVALENT AND
TEMPERATURES THAT COULD KEEP THAT AS SNOW OVER THE INTERIOR. AS THIS
IS A DAY 6 FORECAST...WILL KEEP AN EYE ON THIS POTENTIAL STORM BUT
NOT GET TOO EXCITED FOR NOW.

[jinftl]

ugh..i hope this doesn't mean winter weather will threaten st patty's weekend festivities in boston....that is a headline that will get some huge press

NWS BOX (Boston-Taunton) mildly interested. snippet

MODEL SOLUTIONS AGREE ON A STORM FOR THE WEEKEND...AND SIMILAR TIMING FOR SATURDAY NIGHT AND SUNDAY. BUT DIFFERENCES CONTINUE ONCE THE
STORM CENTER MOVES OFFSHORE WITH THE ECMWF FARTHEST SOUTH AND THE
OPERATIONAL GFS WEST OF THE GFS ENSEMBLE MEAN. THE ECMWF ALSO HOLDS
MOST OF THE PRECIP OFFSHORE. WE WILL INSTEAD GO WITH THE GFS
PLACEMENT...WHICH BRINGS 2 TO 4 TENTHS OF WATER EQUIVALENT AND
TEMPERATURES THAT COULD KEEP THAT AS SNOW OVER THE INTERIOR. AS THIS
IS A DAY 6 FORECAST...WILL KEEP AN EYE ON THIS POTENTIAL STORM BUT
NOT GET TOO EXCITED FOR NOW.

[Ed Mahmoud]

NWS Taunton remains interested, but not committed...
(from am AFD)

.LONG TERM /THURSDAY THROUGH MONDAY/...
CONFIDENCE IS NOT HIGH ENOUGH TO MAKE MAJOR CHANGES TO THIS PORTION
OF THE FORECAST THIS MORNING. 11/00Z MODELS ARE IN DECENT AGREEMENT
THROUGH THURSDAY...THEN START TO DIFFER WITH THEIR EVOLUTIONS OF THE
MID LEVEL FLOW. THAT SAID...DOES LOOK MESS TOWARDS THE END OF THIS
WEEK.

WEAK HIGH PRESSURE WILL CROSS SOUTHERN NEW ENGLAND THURSDAY. THIS
SHOULD BE FOLLOWED BY A WEAK LOW PRESSURE THURSDAY NIGHT INTO FRIDAY.
STILL SOME QUESTION HOW FAR SOUTH A LINGERING COLD FRONT WILL MOVE
FROM SOUTHERN NEW ENGLAND FRIDAY NIGHT INTO SATURDAY.

THE LATEST GFS USES THIS FRONTAL BOUNDARY AS A MEANS TO DIRECT A
SIGNIFICANT LOW PRESSURE OUR WAY SATURDAY NIGHT INTO SUNDAY.
HOWEVER...THE 0Z0 GFS ENSEMBLE MEAN TAKES THIS STORM FARTHER
SOUTHEAST. THE ECMWF IS EVEN FARTHER SOUTHEAST...AND MUCH MORE
PROGRESSIVE. WILL NEED TO KEEP AN EYE ON THIS STORM...BUT AM NOT
READY TO COMMIT TO ANY DETAILS YET.

GENERALLY USED THE LATEST MEX GUIDANCE TO TWEAK PREVIOUS FORECAST
TEMPERATURES.

[Ed Mahmoud]

JB has been on board for a couple of days now, and the 18Z WRF is leaning his direction, for what that is worth...

Snip of NWS BOX AFD

SATURDAY-SUNDAY...LOTS OF QUESTIONS COME INTO PLAY FOR THE WEEKEND.
DOES APPEAR THAT THERE MAY BE A BRIEF BREAK IN THE ACTION BEFORE
ANOTHER LOW MAY TRY TO APPROACH FROM THE SW. LEFTOVER FRONTAL TROUGH STUCK S OF NEW ENGLAND WILL BE THE FOCUS OF THIS LOW...BUT MAY GO OUT FURTHER S AS SUGGESTED BY SEVERAL MODELS SUCH AS THE 12Z GFS AND 00Z EC. HOWEVER...12Z GGEM AND NAM TRY TO BRING FURTHER N. WILL NEED TO CONTINUE TO MONITOR THIS. RIGHT NOW...KEPT HIGH CHANCE POPS GOING FOR MAINLY SATURDAY NIGHT INTO SUNDAY MORNING...WITH THE BEST SHOT ALONG THE S COAST. IN EITHER CASE...THE LOW WILL PASS S OF THE
REGION SO COLDER AIR WILL WORK IN CHANGING ANY RAIN OVER TO SNOW.
STILL TOO EARLY TO SUGGEST HOW MUCH WILL FALL BUT...AT THIS POINT...
NOT EXPECTING A WHOLE LOT. STAY TUNED.

[srainhoutx]

HPC certainly is entertaining the idea....


PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
744 AM EDT WED MAR 19 2008

VALID 12Z SUN MAR 23 2008 - 12Z WED MAR 26 2008

...POTENTIAL FOR LATE SEASON SNOWSTORM FROM THE MID ATLANTIC
STATES TO NEW ENGLAND...

MODELS ARE CONVERGING TOWARD EAST COAST/W ATLC CYCLOGENESIS DAY
5...WITH THE 00Z GFS AND GEFS MEAN TRENDING STRONGLY TOWARD THE
DEVELOPED SOLUTION INDICATED BY THE LAST SEVERAL RUNS OF THE ECMWF
AND ECMWF ENSEMBLE MEAN. SEVERAL OF THE 00Z GFS ENSEMBLE MEMBERS
ARE AS INTENSE AS THE 00Z ECMWF WITH THIS LOW...WITH A SIMILAR
TRACK FROM SOUTH OF CAPE HATTERAS TO THE ATLANTIC BENCHMARK.
TAKEN LITERALLY...THIS GUIDANCE THREATENS A FOOT OF SNOW FROM NEAR
RICHMOND NORTHEASTWARD TO BOSTON...INCLUDING WASHINGTON
DC...PHILADELPHIA...AND NEW YORK CITY. THERE IS PLENTY OF
PRECEDENT FOR LATE SEASON HEAVY SNOWFALL...EVEN OVER THE CAROLINAS
AND SOUTHERN MID ATLANTIC REGION. IN MANY WAYS...MARCH IS AN
IDEAL MONTH FOR LARGE STORMS AND IF EVERYTHING COMES TOGETHER
RIGHT...THEY CAN BE HISTORIC EVENTS. SOME OF THE YEARS THAT HAD
DEEP LATE SEASON SNOWS AFFECTING PORTIONS OF THIS REGION IN THIS
REGION IN LATE MARCH 1942 1958 1964 1971 1974 1983.

http://www.hpc.ncep.noaa.gov/preepd/preepd.html

[Ed Mahmoud]

Different Megastorm than what thread was started for, copied from my DFW Easter Miracle (not looking good, but then it wouldn't be a miracle, would it?) thread



0Z Canadian still keeps precip and cold air apart (but a nice Northeast snow that could cancel school in Massapequa, NY on Tuesday) in DFW area.

More tragically, the 0Z GFS seems to have backed off a miracle.


Note also GFS doesn't cancel school on Long Island on Tuesday.


Euro looks half way in between, and may cancel school Tuesday.

[srainhoutx]

I do think that this is something to keeep an eye on for a big chunk of real estate from the Mid Atlantic through the NE...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
509 AM EDT THU MAR 20 2008

VALID 12Z MON MAR 24 2008 - 12Z THU MAR 27 2008

...POTENTIAL FOR LATE SEASON SNOWSTORM FOR PORTIONS OF THE EAST
COAST...
THE 00Z GFS AND GEFS MEAN ARE OUT OF SYNC WITH THE OTHER GLOBAL
GUIDANCE...INCLUDING THE ECMWF...CANADIAN...AND UKMET
MODELS...WITH THE MID LEVEL AMPLIFICATION OF THE FLOW OVER THE
EASTERN UNITED STATES DAYS 4 AND 5. THE GFS AND ITS MEAN HAVE
WAVERED BACK AND FORTH BETWEEN DEVELOPED AND FLAT SOLUTIONS DURING
THE LAST TWO DAYS...AND ARE NOW OUTLIERS INDICATING NO
CYCLOGENESIS ALONG THE ATLANTIC SEABOARD. COULD ONLY FIND ONE GFS
ENSEMBLE MEMBER FROM THE 00Z CYCLE THAT HAD A SOLUTION SIMILAR TO
THE PREFERRED ECMWF AND GEM GLOBAL MODELS. THE ECMWF HAS
CONSISTENTLY PREDICTED A SIGNIFICANT STORM OVER THE EAST...THOUGH
IT HAS VARIED ON HOW FAR WEST OR EAST THE SYSTEM TRACKS. THIS
CURRENT RUN IS ON THE WEST SIDE OF THE GUIDANCE...WITH MORE
PHASING INDICATED WITH A NORTHERN STREAM SHORT WAVE DROPPING INTO
THE GREAT LAKES. THIS NORTHERN STREAM FEATURE IS NOT EASY TO RULE
ON ONE WAY OR ANOTHER...BUT GAVE IT CREDIT IN THE PRELIMINARY
PROGS SINCE THE ECMWF OFTEN LEADS THE WAY WITH SUCH SUBTLE TRENDS.
THE INCORPORATION OF THIS NEW ENERGY HAS THE EFFECT OF DRAWING
THE ENTIRE ATLANTIC SYSTEM CLOSER TO THE NEW ENGLAND COAST...WHICH
THREATENS SOUTHEASTERN NEW ENGLAND WITH BLIZZARD CONDITIONS DAY 5.


http://www.hpc.ncep.noaa.gov/preepd/preepd.html

Give the models time to get a handle of this mess.

[Ed Mahmoud]

If I keep this thread going long enough, eventually, I'll get the Storm of the Winter in NYC, unless, of course, winter ends too soon.


I started this thread for a storm the GFS was on, then backed away, and then Joe Bastardi got on it, then that one busted. I've had two SE Texas severe t-storm and this bust.

I did spot the busted NYC snow storm about six weeks ago as a bust before the local NWS did, so I'm batting .250 the last six weeks.

[srainhoutx]

Updated Prelim Disco out...snipet...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1000 AM EDT THU MAR 20 2008

VALID 12Z MON MAR 24 2008 - 12Z THU MAR 27 2008


WHILE THERE IS STILL SOME POTENTIAL FOR AN AN EARLY SPRING
SNOWSTORM DAY 4/MON ALONG THE MID ATLANTIC AND NEW ENG
COASTS...THE INTENSITY OF THE SYS SHOWN BY THE
ECMWF/CANADIAN/UKMET MODELS IS NOT WELL SUPPORTED BY THE LARGE
SCALE PATTERN. THE 00Z/20 ECMWF ENSEMBLE MEAN SEEMS LIKE A GOOD
COMPROMISE BETWEEN THE MORE AMPLIFIED ECMWF/UKMET/CANADIAN
SOLUTIONS AND THE LESS AMPLIFIED GFS FAMILY OF SOLUTIONS...NOT
ONLY WITH THE TUE SYS ALONG THE E COAST BUT WITH MOST OF THE OTHER
SYNOPTIC FEATURES ON THE MAP AS WELL. THE UPDATED MANUAL PROGS
INCORPORATED A BLEND OF 50% ECMWF ENSEMBLE MEAN WITH 50% OF THE
OPERATIONAL ECMWF....SLIGHTLY ON THE STRONGER SIDE OF THE MIDPOINT
OF THE ENVELOPE OF SOLUTIONS ALONG THE E COAST.

THE MAIN FACTOR OPPOSING A REALLY BIG DEVELOPMENT ALONG THE E
COAST WILL BE THE BREAKDOWN/FLATTENING OF THE SUPPORTING UPSTREAM
UPPER RIDGE OVER THE NRN ROCKIES MON DAY 4 BY PACIFIC ENERGY. THE
TIMING OF THE ARRIVAL OF THE PACIFIC ENERGY ALONG THE PACIFIC NW
COAST IS CRITICAL TO THE DOWNSTREAM AMPLITUDE OF THE UPPER SYS
APPROACHING THE APLCHNS AT THAT TIME. EVEN A 12 HOUR DELAY OF
HEIGHT FALLS ARRIVING IN THE THE PACIFIC NW FROM THAT OF THE
GFS/ECMWF COULD TILT THE SCALES TOWARDS A BIGGER SYS ALONG THE E
COAST...FAVORING MORE AMPLITUDE MON AS AN UPPER TROF APPROACHES
THE ATLANTIC COAST.

http://www.hpc.ncep.noaa.gov/preepd/preepd.html

We shall see as this s/w arrives near Seattle tomorrow and how the models react as obs sounding data is ingested to output.

[brunota2003]

MHX is watching closely:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
302 PM EDT THU MAR 20 2008

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
ADDED A SLIGHT CHC FOR LIGHT PCPN AS BACKDOOR BNDRY DROPS
THRU NRN AREAS SAT EVE. TEMPS HELD UP IN THE 40S SAT NIGHT
WITH THE CLOUD CVR AND BNDRY LAYER MIXING BUT HIGHS ON EASTER
SUNDAY DROP 10-15 DEGS FM SATURDAYS READINGS. 12Z OPGFS STILL
SUPPRESSING CSTL DEVELOPMNT WELL OFF SE COAST BUT DOESNT HV
SUPPORT FROM OTHER MODELS/EMSEMBLES SO GENERALLY DISREGARDED
FOR NOW. AWAITING 12Z ECMWF BUT AVAILABLE MODEL SUITE STILL
POINTS TO POTENTIAL FOR CYCLOGENESIS CLOSER TO THE COAST ON
SUN NGT/MON. THERMAL PROFILES SUGG MAINLY A RAIN EVENT WITH
SOME MIXED WET SNOW POTENTIAL FAR NW FCST AREA. CONFIDENCE ON
PCPN/PTYPE DETAILS AND POTENTIAL WINDS/COASTAL FLOOD IMPACTS
LOW ATTM BUT WILL HOPEFULLY BE INCREASING AS MODELS COME MORE
INTO ALIGNMENT IN THE NEXT FEW DAYS.