Major Winter Storm for East Coast next week

[ronjon]

Models are starting to converge on the first major nor'easter for the Atlantic coast next Tuesday through Thursday. Heavy snow, sleet, and freezing rain could affect a large area from North Carolina north to Maine. From NWS for NYC:

...POTENTIALLY SIGNIFICANT WINTER STORM COULD EFFECT THE TRI-
STATE FROM TUESDAY AFTERNOON THROUGH LATE WEDNESDAY...

AN AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE SOUTHERN
PLAINS MONDAY...THEN TRACK EAST TO THE TENNESSEE RIVER VALLEY BY
TUESDAY...WHEN A SECONDARY AREA OF LOW PRESSURE WILL FORM OFF THE
SOUTHEAST COAST. THE COASTAL LOW BECOMES THE PRIMARY LOW BY
WEDNESDAY MORNING OFF THE VIRGINIA OR NORTH CAROLINA COAST. THIS
LOW WILL INTENSIFY AS IT SLOWLY LIFTS NORTHEAST TO EAST OF CAPE
COD BY THURSDAY MORNING...AND TO NOVA SCOTIA BY THURSDAY EVENING.

COLD AIR WILL ALREADY BE IN PLACE ACROSS THE REGION AHEAD OF THE
STORM AS HIGH PRESSURE BUILDS IN FROM SOUTH CENTRAL CANADA FROM MONDAY
NIGHT INTO WEDNESDAY. THE COMBINATION OF THIS COLD AIR...AND
ATLANTIC MOISTURE BEING PUSHED INTO THE REGION AHEAD OF THE
STORM...GIVES THE POTENTIAL FOR SIGNIFICANT SNOW FALL FROM LATE
TUESDAY THROUGH LATE WEDNESDAY.

BEST INDICATIONS ARE THAT SNOW SHOULD DEVELOP TUESDAY AFTERNOON
ACROSS NORTHEAST NEW JERSEY...THE LOWER HUDSON VALLEY...AND METRO
NEW YORK CITY...THEN CONTINUE TO OVERSPREAD THE ENTIRE TRI-STATE
TUESDAY EVENING. CURRENT EXPECTATIONS ARE FOR THE HEAVIEST AND
STEADIEST SNOW FALL TO OCCUR FROM LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING...WITH THE SNOW TAPERING OFF FROM WEST TO EAST
WEDNESDAY AFTERNOON AND EVENING.

From NWS Balt/DC:

...WINTER STORM WATCH IN EFFECT FROM TUESDAY MORNING THROUGH
WEDNESDAY MORNING...

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A
WINTER STORM WATCH...WHICH IS IN EFFECT FROM TUESDAY MORNING
THROUGH WEDNESDAY MORNING.

A LOW PRESSURE SYSTEM MOVING OUT OF THE PLAINS STATES AND DEVELOPING
OFF THE SOUTHEAST COAST OF THE UNITED STATES WILL AFFECT THE MID
ATLANTIC EARLY NEXT WEEK.

ACCUMULATING WINTRY PRECIPITATION IS EXPECTED TO BEGIN OVER NORTHERN
AND CENTRAL VIRGINIA...CENTRAL AND WESTERN MARYLAND...EASTERN WEST
VIRGINIA...AND THE DISTRICT OF COLUMBIA MONDAY AFTERNOON AND
EVENING. OVER THE SHENANDOAH VALLEY...CENTRAL VIRGINIA FOOTHILLS AND
LOWER SOUTHERN MARYLAND...PRECIPITATION MAY BEGIN AS A WINTRY MIX OF
SNOW...SLEET AND FREEZING RAIN AND CONTINUE THROUGH EARLY TUESDAY.

THE HEAVIER SNOWFALL IS STILL EXPECTED TO OCCUR TUESDAY AND TUESDAY
NIGHT AS A COASTAL LOW PRESSURE SYSTEM INTENSIFIES OFF THE MID
ATLANTIC COAST. WHILE THERE IS STILL SOME UNCERTAINTY WITH THE
TIMING AND EXACT TRACK OF THE SYSTEM...A HIGH IMPACT WEATHER EVENT
IS LIKELY.

[JBG]

What level of confidence can there be for such a forecast this far in advance? I have noticed, over the years, many times we get excited about this kind of event, and wake up to either nothing, or a rainstorm.

[ronjon]

From HPC Disc:

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
954 AM EST SUN FEB 11 2007

VALID 12Z THU FEB 15 2007 - 12Z SUN FEB 18 2007

...A MAJOR MID-ATLANTIC/NERN US WINTER STORM...

...E-CENTRAL US...

HPC PROGS AND PREFERRED GUIDANCE DEPICTS SHORT RANGE SRN STREAM
SYSTEM/STORM EJECTION THRU THE MID-ATLANTIC THAT LEADS TO
SIGNIFICANT MID THRU LATE WEEK MID-ATLANTIC THEN NEW ENG/CANADIAN
MARITIME COASTAL LOW CYCLOGENESIS. NRN STREAM INTERACTION IS KEY
TO STORM DETAILS THAT MAY NEED SHORTER RANGE GUIDANCE TO
ACCURATELY DEPICT...BUT THE MAJOR WINTER STORM WILL BE A MAJOR
SNOW/ICE PRODUCER OVER THE MID-ATLANTIC BEFORE THREATENING HEAVY
SNOW/BLIZZARD CONDITIONS FOR NEW ENG

[Stephanie]

JBC - the models have been "hinting" at this storm for the past week and each time they've been revised, it still shows up. We're only talking 2 - 3 days out now so the confidence level is alot higher at this time.

[Stephanie]

Looks like it'll be too warm for snow now per the GFS 12 UTC;

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _072.shtml

[Fodie77]

You know, we already have 3 page thread for this. I don't think we need another.

http://www.storm2k.org/phpbb2/viewtopic.php?t=92852

[Stephanie]

The latest for my area - they're not totally buying into the warm air just yet;

Special Weather Statement
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
305 PM EST SUN FEB 11 2007

DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054-
055-060>062-067>071-121000-
NEW CASTLE-KENT DE-INLAND SUSSEX-DELAWARE BEACHES-CECIL-KENT MD-
QUEEN ANNE'S-TALBOT-CAROLINE-SUSSEX-WARREN-MORRIS-HUNTERDON-
SOMERSET-MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM-
GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-
ATLANTIC-CAPE MAY-ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC-
COASTAL OCEAN-SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH-
NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...DOVER...GEORGETOWN...
REHOBOTH BEACH...ELKTON...CHESTERTOWN...CENTREVILLE...EASTON...
DENTON...NEWTON...WASHINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...FREEHOLD...SANDY HOOK...TRENTON...
PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...MOORESTOWN...
MOUNT HOLLY...JACKSON...MILLVILLE...HAMMONTON...
CAPE MAY COURT HOUSE...OCEAN CITY...ATLANTIC CITY...
LONG BEACH ISLAND...WHARTON STATE FOREST...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA
305 PM EST SUN FEB 11 2007

...A SIGNIFICANT WINTER STORM TO IMPACT THE REGION FROM TUESDAY
AFTERNOON THROUGH WEDNESDAY MORNING...

A COLD FRONT WILL MOVE ACROSS THE REGION LATE IN THE DAY ON MONDAY.
AS A RESULT, ANOTHER ROUND OF EVEN COLDER AIR WILL SETTLE INTO THE
REGION DURING MONDAY NIGHT AND TUESDAY AS A STRONG AREA OF HIGH
PRESSURE BUILDS ACROSS SOUTHEASTERN CANADA.

LOW PRESSURE, DEVELOPING IN THE PLAINS MONDAY, IS FORECAST TO
APPROACH OUR AREA FROM THE SOUTHWEST ON TUESDAY. THIS LOW IS
EXPECTED TO WEAKEN DURING TUESDAY NIGHT AS ANOTHER AREA OF LOW
PRESSURE DEVELOPS ALONG THE NORTH CAROLINA COAST. THIS SECOND AREA
OF LOW PRESSURE WILL INTENSIFY QUICKLY AS IT MOVES NORTHEASTWARD,
EAST OF THE MID ATLANTIC COAST ON WEDNESDAY BEFORE REACHING NEW
ENGLAND WEDNESDAY NIGHT. HOWEVER, IT SHOULD BE STRESSED THAT THIS
TRACK STILL HAS SOME UNCERTAINTY INVOLVED AND THAT A SHIFT TO THE
NORTH OR SOUTH WILL GREATLY IMPACT THE PRECIPITATION AMOUNTS AND
EVEN TYPES OUR REGION SEES.

HOWEVER, THIS STORM HAS A GOOD POTENTIAL TO BRING A SIGNIFICANT
SNOWFALL TO A LARGE PORTION OF THE AREA. WHILE IT IS STILL A LITTLE
TO SOON TO BE MORE SPECIFIC, AREAS FROM THE INTERSTATE 95 CORRIDOR
ON NORTH AND WESTWARD SEEM TO HAVE A HIGHER CHANCE OF GETTING
SIGNIFICANT SNOW FROM THIS STORM. AREAS TO THE SOUTH AND EAST MAY
TEND TO HAVE SNOW GO OVER TO A MIXTURE OF SLEET AND FREEZING RAIN,
WITH PERHAPS EVEN PLAIN RAIN CLOSER TO THE NEW JERSEY SHORE AND
PORTIONS OF DELAWARE AND MARYLAND. AGAIN, THIS ALL DEPENDS ON THE
EXACT TRACK OF THE STORM. IN ADDITION, THE SYSTEMS ARRIVAL COULD BE
A LITTLE SLOWER, WITH THE HEAVIEST PRECIPITATION NOW LOOKING TO FALL
DURING TUESDAY NIGHT AND WEDNESDAY MORNING.

DURING AND PARTICULARLY BEHIND THE STORM, GUSTY WINDS SHOULD DEVELOP
AND DEPENDING ON THE SNOW AMOUNTS THAT OCCUR, BLOWING AND DRIFTING
SNOW COULD BECOME A CONCERN.

SINCE THE DETAILS OF THIS STORM ARE STILL UNCERTAIN, A WINTER
STORM WATCH WILL NOT BE ISSUED AT THIS TIME. THE NATIONAL WEATHER
SERVICE WILL CONTINUE TO MONITOR THE DEVELOPMENT OF THIS WINTER
STORM, AND ISSUE ADDITIONAL UPDATES INCLUDING THE POTENTIAL OF A
WINTER STORM WATCH. EVERYONE IS URGED TO STAY TUNED TO NOAA
WEATHER RADIO ALL HAZARDS OR YOUR LOCAL MEDIA OUTLET FOR THE
LATEST UPDATES AS THIS STORM LOOKS TO BRING A PRECIPITATION MESS
TO OUR AREA.

$$

GORSE/EBERWINE

[Nimbus]

A little more involved forecast from further north.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
324 PM EST SUN FEB 11 2007


.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...

...CONFIDENCE LEVEL BECOMING HIGH FOR POTENTIAL MAJOR NOREASTER
FOR THE ENTIRE FORECAST AREA WEDNESDAY THROUGH THURSDAY...

ARCTIC HIGH PRES BUILDS ACROSS THE REGION MONDAY NIGHT AND
TUESDAY WITH BITTER COLD TEMPS ONCE AGAIN FORECAST. ALL MODELS IN
GENERAL AGREEMENT DEVELOPING A SECONDARY LOW OFF OF MID ATLATIC
COAST TUESDAY NIGHT AND THEN ALLOWING IT TO TRACK NORTHEAST AND
HUG THE COAST WED AND WED NIGHT. GFS AND ETA TRIES MOVING THE CENTER
INLAND ACROSS SOUTEHRN NEW ENGLAND BUT 12Z ECMWF MOVES IT OUT OVER
CAPE COD WHICH IS THE PREFERRED SCENARIO. WITH SUCH A COLD ARCTIC
DOME INITIALLY OVER NORTHERN NEW ENGLAND I FIND IT WILL BE VERY
DIFFICULT TO BELIEVE WARM AIR WILL MOVE FAR ENOUGH NORTH AND
OVERTAKE AND BREAK DOWN THE COLD AIR DAMMING. MODELS ALSO HAVE A
HISTORY OF MAKING ATTEMPTS TO MOVE LOWS INLAND AND OFTEN END UP
TOO FAR W SINCE LOW SHOULD TRACK ALONG THE DEVELOPING COASTAL
FRONT WHICH DEVELOPS ALONG THE EASTERN NEW ENGLAND COAST. WITH THIS
SYSTEM TREMENDOUS LIFT WILL BE GENERATED WITH STRONG ESELY FLOW
ALOFT OVERUNNING THE ARCTIC DOME...ALSO SYSTEM WILL ALREADY HAVE
TAPPED PLENTY OF MOISTURE OFF THE ATLANTIC TO BOOT. GFS MODEL GIVES
3+ INCHES OF QPF ACROSS MUCH OF THE AREA WHICH WOULD EQUATE TO AN
AWFUL LOT OF SNOW...ONLY PLACES THAT MAY MIX WOULD BE ALONG THE
IMMEDIATE COAST. ALL OTHER MODELS ALSO GIVE SIGNIFICANT QPF. WINDS
SHOULD ALSO ALLOW FOR PLENTY OF BLOWING AND DRIFTING OF THE SNOW.
AT THIS POINT THERE IS NO NEGATIVE OUTLIER MODEL TO LOOK AT AND
MODELS GIVE ME CONSIDERABLE CONFIDENCE SINCE THEY ALL GENERALLY
AGREE ON SCENARIO.

WE HAVE ISSUED AN SPS AND A HAZARDOUS WEATHER OUTLOOK FOR THE
POTENTIAL OF A MAJOR EVENT TO OCCUR ON WEDNESDAY THROUGH THURSDAY.

[Lowpressure]

This thing is turning into a rain event for many more than originally thought. North Carolina now forecasting all rain, except mountains. DC now talking change over with high degree of uncertainty regarding rain/snow line. Warm talk keeps moving up the coast. Set up just not ideal no matter how bad we want it. High not dominant enough and track keeps nudging the wrong way.