March big dog storm has been nutered

[no looking back]

Rumors of a Huge Nor easter is gonna form. Any Updates?

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HPC

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
309 AM EST WED FEB 24 2010

VALID 12Z SUN FEB 28 2010 - 12Z WED MAR 03 2010

...SIGNIFICANT SNOWFALL AGAIN POSSIBLE ACROSS THE DEEP
SOUTH/CAROLINAS/VIRGINIA EARLY TO MID NEXT WEEK...
THE MODELS CONTINUE TO ADVERTISE A RETROGRADING POSITIVE MID-LEVEL
HEIGHT ANOMALY FROM EASTERN INTO CENTRAL CANADA...WHICH SHOULD
ALLOW THE NORTHEAST VORTEX TO EXIT STAGE RIGHT DURING THE FIRST
HALF OF THE PERIOD YET TRAP SOME MID-LEVEL ENERGY ACROSS THE
MIDWEST DURING THE MEDIUM RANGE PERIOD. REPERCUSSIONS ARE MANY
FOR ITS INTERACTION WITH THE NEXT NEARLY CLOSED CYCLONE
ALOFT/STRONG SHORTWAVE WHICH SPLITS OUT OF THE EASTERN PACIFIC
TROUGH EVENTUALLY MOVING THROUGH THE SOUTHERN TIER OF THE
COUNTRY...AND WHETHER OR NOT THE ENERGY IN THE MIDWEST IS STRONG
ENOUGH TO LURE THE SOUTHERN SYSTEM NORTHWARD OR MERGE WITH
IT...AND IF SO HOW FAR NORTH THE COMBINED SYSTEM COULD MOVE. WITH
A TWO DAY TREND SOMEWHAT TO THE SOUTH NOTED AMONGST THE 12Z
MULTI-MODEL ENSEMBLE MEMBERS...FELT THE BEST COURSE OF ACTION WAS
TO GO IN THE MIDDLE OF THE ENSEMBLE CLUSTERING RATHER THAN THE
NORTHERN SIDE AS WAS DONE THIS TIME THE LAST COUPLE DAYS. THIS
SOLUTION ADVERTISES A POSSIBLE SNOWSTORM TO THE DEEP
SOUTH/CAROLINAS/SOUTHEAST VIRGINIA MONDAY INTO WEDNESDAY OF NEXT
WEEK AS AT LEAST ONE-FIFTH OF THE 12Z ECMWF ENSEMBLE MEMBERS CLOSE
OFF A VORTEX AT 500 HPA WITH HEIGHTS BELOW 5400 METERS ACROSS
GEORGIA....THOUGH A NUMBER OF 12Z GEFS/CANADIAN MEMBERS ARE
LOCATED MORE OVER THE MID-ATLANTIC STATES LATE IN THE PERIOD.
NEEDLESS TO SAY...UNCERTAINTY ABOUNDS CONCERNING THIS FORECAST AS
FUJIWARA/BINARY INTERACTION SCENARIOS ARE HARD TO DEAL WITH IN THE
SHORT RANGE PERIOD...LET ALONE DURING THE MEDIUM RANGE PERIOD.
THE PRESSURES USED A COMPROMISE OF THE 00Z ECMWF/00Z GFS WHICH WAS
ADJUSTED TOWARD THE 12Z MULTI-MODEL ENSEMBLE LOW CLUSTERING.

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HPC

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
313 AM EST THU FEB 25 2010

VALID 12Z MON MAR 01 2010 - 12Z THU MAR 04 2010

...SIGNIFICANT SNOW THREAT FOR THE SOUTHEAST/CAROLINAS/VIRGINIA
EARLY TO MID NEXT WEEK...THE MODELS CONTINUE TO ADVERTISE A RETROGRADING POSITIVE MID-UPPER
LEVEL HEIGHT ANOMALY MOVING ACROSS CANADA. THIS SHOULD ALLOW A
CLOSED NORTHEAST VORTEX TO EXIT STAGE RIGHT OVER THE WEEKEND...YET
TRAP SOME MID-LEVEL ENERGY BACK ACROSS THE UPPER MIDWEST IN 3-4
DAYS. REPERCUSSIONS ARE MANY FOR ITS INTERACTION WITH A NEARLY
CLOSED CYCLONE ALOFT/STRONG SHORTWAVE WHICH SPLITS OUT OF THE
EASTERN PACIFIC TROUGH IN A POTENT SOUTHERN STREAM TYPICAL OF THE
EL NINO CLIMATE PATTERN TO NEAR THE FOUR CORNERS BY SUNDAY. THIS
ENERGETIC FLOW/SYSTEM THEN PROGRESSES EASTWARD OVER THE SOUTHERN
TIER OF THE COUNTRY...WITH QUESTION MARKS WITH RESPECT TO WHETHER
OR NOT DIGGING MIDWEST NORTHERN STREAM ENERGY IS STRONG ENOUGH TO
LURE THE SOUTHERN SYSTEM NORTHWARD OR MERGE WITH IT...AND IF SO
HOW FAR NORTH THE COMBINED SYSTEM COULD MOVE. SO FAR...THE
GUIDANCE DOES NOT INDICATE MUCH OF A NORTHWARD TUG ON THE SOUTHERN
STREAM CYCLONE. THE MULTI-MODEL ENSEMBLE MEMBERS STAND THEIR
GROUND...CLUSTERING ALONG A COASTAL PATH FROM JUST OFFSHORE THE
MOUTH OF THE MISSISSIPPI RIVER TO JUST OFFSHORE THE CAROLINAS...SO
STAYED IN THE MIDDLE OF THE ENSEMBLE CLUSTERING WHICH IS CLOSE TO
THE 00Z ECMWF SOLUTION. THIS SOLUTION ADVERTISES A SNOWSTORM
THREAT ACROSS THE SOUTHERN ROCKIES SUNDAY AND THEN FROM NORTHERN
GEORGIA EAST-NORTHEAST INTO THE LOWER MID-ATLANTIC STATES MONDAY
INTO WEDNESDAY NEXT WEEK AS A DECENT CLUSTER OF ECMWF/GEFS
ENSEMBLE MEMBERS CLOSE OFF A VORTEX AT 500 HPA WITH HEIGHTS BELOW
5400 METERS. THERE REMAIN ENSEMBLE MEMBERS ARE LOCATED MORE
NORTHWARD OVER THE MID-ATLANTIC STATES....SO SOME UNCERTAINTY
REMAINS CONCERNING THESE IMPORTANT SMALLER SCALE DETAILS AND
INTERACTIONS OF THIS FORECAST. STARTED WITH A 00Z ECMWF/00Z GEFS
MEAN COMPROMISE SOLUTION BEFORE ADJUSTING TOWARDS ENSEMBLE
CLUSTERING... PARTICULARLY NEAR THE SOUTH AND EAST. DESPITE
UNCERTAINTIES WITH EMBEDDED SYSTEM DETAILS...LARGER SCALE FLOW
DEPICTION FROM THE MODELS AND ENSEMBLES ARE ACTUALLY QUITE
SIMILAR...WITH BELOW NORMAL FORECAST SPREAD LEADING TO ABOVE
AVERAGE FORECASTER CONFIDENCE.

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NWS JAN

CONFIDENCE IS INCREASING FOR A STORM SYSTEM TO AFFECT THE ARKLAMISS
REGION EARLY IN THE UPCOMING WEEK. THE PRIMARY IMPETUS WILL BE A
VIGOROUS MID/UPPER-LEVEL TROUGH THAT WILL TRAVERSE THE AREA EARLY NEXT
WEEK. THIS DISTURBANCE IS CURRENTLY ASSOCIATED WITH A CLOSED
MID/UPPER CYCLONIC CIRCULATION OVER THE NORTH PACIFIC CENTERED NEAR
45N155W. WATER VAPOR IMAGERY INDICATES A WELL-DEFINED BAROCLINIC LEAF
IN THE EASTERN SEMICIRCLE OF THIS SYSTEM...SUGGESTING FURTHER
DEVELOPMENT AS AN APPROACHING UPPER LEVEL JET MAXIMUM FORCES THE
TROUGH TO DIG SOUTHWARD AS IT APPROACHES THE WEST COAST. THROUGH
SUNDAY...NWP GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH REGARDS TO THE
CHARACTERISTICS OF THIS SYSTEM...TAKING IT ON AN EASTWARD TRACK
ACROSS THE FOUR-CORNERS REGION AND INTO THE SOUTH CENTRAL CONUS.
THEREAFTER...DISAGREEMENT AMONGST GUIDANCE GROWS AS THE TROUGH
APPROACHES THE CWA.

A SIGNIFICANT FACTOR INFLUENCING THE TRACK OF THE APPROACHING
MID/UPPER WAVE WILL BE A BROAD AND DEEP CUT-OFF CYCLONIC CIRCULATION
CENTERED OVER THE NORTHEAST CONUS. THROUGH SUNDAY...THIS FEATURE IS
FORECAST TO REMAIN VERTICALLY-STACKED AND ASSOCIATED WITH AN INTENSE
SURFACE LOW HAVING A MEAN CENTER OVER SOUTHEAST NEW YORK. GOING INTO
LATE SUNDAY AND MONDAY...THE ECMWF...NOGAPS...CMC...NEARLY EVERY
MEMBER OF THE CMC ENSEMBLES...AND A HANDFUL OF THE MEMBERS OF THE
GEFS ALL KICK THE DEEP-LAYER CYCLONE OFF THE EAST COAST...MAKING WAY
FOR THE SOUTH CENTRAL CONUS DISTURBANCE TO TAKE AN EASTWARD
TRAJECTORY WITH THE STRONGEST ASCENT PASSING ACROSS THE LOWER
MISSISSIPPI RIVER VALLEY AND NORTHERN GULF FROM MONDAY AFTERNOON
INTO TUESDAY.

WHAT THE GFS AND SOME OF THE GFS ENSEMBLE MEMBERS DO WITH THESE
FEATURES IS RATHER QUESTIONABLE. THESE MODELS ENTIRELY DECOUPLE THE
NORTHEAST CONUS CYCLONE...WITH THE INTENSE SURFACE LOW MERGING WITH A
NORTHEASTWARD-RACING CYCLONE OVER THE WESTERN NORTH ATLANTIC THUS
ALLOWING THE MID/UPPER LEVEL CIRCULATION TO LAG BEHIND OVER INLAND
AREAS. GIVEN THE WESTWARD DISPLACEMENT OF THE MID/UPPER CYCLONE IN
THE GFS/GEFS...THE SOUTH CENTRAL CONUS DISTURBANCE WOULD BE
SUPPRESSED SUBSTANTIALLY TO THE SOUTH...WITH THE OPERATIONAL GFS
INDICATING THE GREATEST SUPPRESSION. THIS SUPPRESSION WOULD BE
FURTHER ENHANCED BY SHORTWAVE ENERGY FORECAST TO DIVE SOUTHWARD AT
THE WESTERN PERIPHERY OF THE NORTHEAST CONUS CIRCULATION. THE
AFOREMENTIONED DECOUPLING AND WESTWARD LAG EVIDENT IN THE GFS/GEFS
HAS LITTLE BACKING FROM ANY OTHER GUIDANCE...AND THE PHYSICAL
JUSTIFICATION FOR THIS DECOUPLING IS QUESTIONABLE GIVEN LACK OF
STRONG DEEP-LAYER SHEAR ACTING ON THE LARGE-SCALE CIRCULATION AND ITS
ANTECEDENT WELL-DEVELOPED VERTICAL STRUCTURE.

THUS...THIS FORECAST PACKAGE WILL DISCOUNT THE GUIDANCE WHICH
SUPPRESSES THE SOUTH CENTRAL CONUS DISTURBANCE TO THE SOUTH BY A
LAGGING MID/UPPER CYCLONE OVER THE NORTHEAST CONUS...AND WILL FOLLOW A
BLEND OF THE ECMWF/CMC/CMC ENSEMBLES. AS THE SHORTWAVE APPROACHES
THE SOUTHEAST CONUS LATE SUNDAY INTO MONDAY...A SURFACE LOW IS
FORECAST TO DEVELOP OVER SOUTH TEXAS AND THEN TRACK EASTWARD ACROSS
THE NORTHERN GULF ALONG 27N/28N. THE ECMWF SHOWS A MINIMUM CENTRAL
PRESSURE FALL OF 5 MB IN 6 HOURS BETWEEN 00Z AND 06Z ON
TUESDAY...AND THIS SEEMS ENTIRELY PLAUSIBLE GIVEN THE STRENGTH OF
Q-VECTOR CONVERGENCE DOWNSTREAM OF THE MID/UPPER TROUGH AXIS.
INTERESTINGLY...BECAUSE THE GFS SUPPRESSES THE UPPER WAVE SO FAR
SOUTH...ITS ATTENDANT SURFACE LOW FOLLOWS A TRACK FROM THE YUCATAN
PENINSULA ACROSS THE YUCATAN CHANNEL TO WESTERN CUBA. THIS SOLUTION
IS CERTAINLY AN OUTLIER...AND MOST OF THE GEFS MEMBERS SHOW A TRACK
MUCH FURTHER TO THE NORTH WITH A CLUSTER ALONG 26N.

SINCE THE PRECIP FORECAST WILL BE TIED TO THE TRACK OF THE
SURFACE LOW...THE GFS IS INDICATING NO PRECIP ACROSS THE ARKLAMISS
REGION WITH VERY LOW POPS FROM MEX GUIDANCE...AND THESE SOLUTIONS
ARE BEING DISCOUNTED WITH FORECAST POPS RAISED WELL ABOVE MEX
GUIDANCE. FOLLOWING A BLEND OF THE ECMWF/CMC/CMC ENSEMBLES...PRECIP
WILL OVERSPREAD THE REGION MONDAY AND CONTINUE INTO MONDAY NIGHT AND
EARLY TUESDAY MORNING. THERMAL PROFILES WILL BE FAVORABLE FOR SNOW TO
MIX IN ACROSS THE NORTHERN THIRD OF THE CWA FOR MONDAY NIGHT...WHEN
THE ECMWF IS INDICATING WET-BULB ZERO (WBZ) HEIGHTS BELOW 1500 FT.
HOWEVER...STRONG ADIABATIC COOLING DUE TO FORCED ASCENT AND MELTING
PROCESSES ALOFT COULD COOL THE LOWER/MID TROPOSPHERE EVEN MORE.
OR...THE LOW COULD TRACK A LITTLE FURTHER TO THE SOUTH GIVING A
LARGER PART OF THE AREA LOWER WBZ HEIGHTS. IN THESE CASES...SNOW
WOULD BECOME A MORE PREDOMINANT PRECIP TYPE. AND IF THIS
OCCURS...STRONG ASCENT THROUGHOUT SATURATED AND DEEP DENDRITIC GROWTH
ZONES APPROACHING 100 MB THICK WOULD BE VERY SUPPORTIVE OF HEAVY
SNOW. THERE WILL ALSO BE CONCERN FOR STRONG GRADIENT WINDS IN THE
NORTHERN SEMICIRCLE OF THE LOW. HOWEVER...A LOW TRACK TO THE NORTH
WOULD RESULT IN WARMER THERMAL PROFILES AND MOSTLY RAIN.
ULTIMATELY...A LOT CAN CHANGE WITH REGARD TO THE CHARACTERISTICS OF
THE AFOREMENTIONED SYNOPTIC FEATURES IN THE NEXT SEVERAL DAYS...BUT
THE POTENTIAL IS THERE FOR A SIGNIFICANT STORM SYSTEM TO AFFECT THE
AREA EARLY NEXT WEEK. GIVEN HIGH UNCERTAINTY IN THE NATURE OF THE
POTENTIAL HAZARDS...MENTION IS BEING WITHHELD FROM THE HAZARDOUS
WEATHER OUTLOOK FOR NOW.

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12z GFS Ensembles 120hrs

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12z ECMWF

120 hrs:



144 hrs:

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HPC

THE SHORTWAVE WITH A STRONG NEG HT ANOMALY MOVING ACROSS TX AND
THE GULF COAST WILL INDUCE HVY RAINS ALONG THE GULF COAST MON AND
TUES AND EWD ACROSS FL INTO GA AND SC. DEEP TROF WITH WELL BELOW
NORMAL HTS/MID/LOW LEVEL TEMPS APPEAR LIKELY TO BRING SNOW ACROSS
THE NRN EDGE OF THE PCPN SHIELD ACROSS NRN AL/GA/SRN AND ERN TN.
AS THE TROF TAKES A MORE NEG TILTED ORIENTATION HEAVIER SNOW FALL
IS POSSIBLE ACROSS THE MTNS OF SC/NC/SWRN VA AND SRN WV. HVY
COASTAL RAINS AND ONSHORE GALE FORCE WINDS WITH HIGH SURF AND
BEACH EROSION/COASTAL FLOODING THREAT CAN BE EXPECTED TUES INTO
THURSDAY ALONG THE SOUTHEASTERN SEABOARD. AS THE MOVES UP EWD
ALONG THE COAST LOW DEEPENS LOWERING 1000-500 MB THICKNESS VALUES
AND H850 TEMPS IMPLY A SIG SNOW VERY POSSIBLY HVY SNOW THREAT FROM
THE NC MTNS AND FOOTHILLS INTO THE PIEDMONT AND NEWD INTO THE
LOWER VA PIEDMONT/TIDEWATER AREAS OF VA AND POSSIBLY LOWER SRN MD
AND LOWER DELMARVA. STRONG N-NE WINDS WILL EXTEND WELL FROM THE
MID ATLC REGION NWD ALONG THE NEW ENG COAST. DETAILS OF PCPN
TYPE/AMOUNTS AND COVERAGE WILL BECOME BETTER DEFINED AS THE EVENT
CLOSES TO WITHIN A 72 HR OR LESS TIMEFRAME.

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Jackson NWS

.SUNDAY NIGHT THROUGH TUESDAY...RAIN IS EXPECTED THIS FORECAST PERIOD WITH THE POSSIBILITY FOR A BRIEF CHANGE TO LIGHT SNOW LATE MON NIGHT/EARLY TUESDAY. MODELS ARE IN SOMEWHAT BETTER AGREEMENT IN THEIR HANDLING OF THE STRONG SRN STREAM MID LEVEL LOW THAT IS FORECAST TO MOVE ACROSS THE SRN PLAINS BEFORE INTERACTING/PHASING WITH THE NRN STREAM...BUT CONFIDENCE IS HIGHER THAT A NRN GULF LOW PRESSURE SYSTEM WILL DEVELOP AND INTENSIFY WITH TIME AS IT MOVES EAST JUST OFF SHORE. AT THIS TIME...WE ARE EXPECTING MOSTLY RAIN WITH THIS EVENT AS MODEL FORECASTED BOUNDARY LAYER TEMPERATURES STAY TOO WARM FOR SNOW UNTIL LATE IN THE EVENT...WHEN GFS WET BULB FREEZING HEIGHTS DROP TO ~1000 FT FOR LOCATIONS ALONG AND EAST OF I-55. IT LOOKS LIKE HEAVY RAIN/CONVECTIVE POTENTIAL WILL STAY MOSTLY TO OUR SOUTH SO THIS
EVENT MAY END UP BEING SOMEWHAT PEDESTRIAN BY SPRING STANDARDS IN THE ARKLAMISS. HOWEVER...SEEING THE GFS UPPER JET SOLUTION WITH 140KT CORE DIVING SOUTHEAST ACROSS TX AND WELL INTO THE GULF OF MEXICO SUGGESTS THIS SYSTEM COULD BRING SURPRISES AND WOULD NOT BE SURPRISED IF EITHER THE RAIN TRENDED HEAVIER OR IF THE ADIABATIC/DIABATIC
COOLING AND SNOW POTENTIAL END UP BEING GREATER THAN ADVERTISED. WE WILL CONTINUE TO KEEP A CLOSE EYE ON MODEL TRENDS FOR THIS EVENT THE NEXT COUPLE OF DAYS. AS FOR TEMPERATURES/POPS...HAVE CUT GFS MOS HIGHS FOR MONDAY WITH THE LIKELY PROSPECT FOR CLOUDY/RAINY WEATHER TO LIMIT DAYTIME HEATING...AND HAVE INCREASED RAIN CHANCES OVER THE HBG AREA MONDAY EVNG WHERE CHANCE POPS LOOK TOO LOW.
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12z GFS Ensemble Mean

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The 12z GFS brings snow down to the Gulfcoast