Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 232058
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
358 PM EST SUN NOV 23 2014

.SYNOPSIS...
A PERIOD OF STORMY WEATHER WILL KICK OFF LATE TONIGHT AS LOW PRES
RAPIDLY DEEPENS OVER THE GREAT LAKES AND DRAWS A WARM FRONT THRU
THE TRI-STATE REGION. A COLD FRONT WILL FOLLOW ON MON NGT. A WEAK
COLD FRONT PASSES THROUGH ON TUESDAY...WITH HIGH PRESSURE BRIEFLY
BUILDING INTO THE THE REGION TUESDAY NIGHT. COASTAL LOW PRESSURE
IMPACTS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT...DEPARTING INTO
THE CANADIAN MARITIMES ON THURSDAY. HIGH PRESSURE THEN BUILDS IN
FROM THE WEST INTO FRIDAY...WITH A ALBERTA CLIPPER SYSTEM POSSIBLE
TO IMPACT THE AREA SATURDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
RADAR COMPOSITE IS JUST BEGINNING TO SHOW THE ADVANCING SHIELD OF
RAIN S OF DC. THE 12Z MODEL DATA WAS ON TRACK WITH THE ONGOING
RAIN FCST SO LITTLE CHANGES WERE NEEDED. TIMING IS STILL AFT
MIDNIGHT INTO MON MRNG...WITH MAINLY A FEW SHWRS THEREAFTER FOR
MOST OF MON. PCPN AMTS AROUND AN INCH.

THE HEAVIEST RAIN DOES LOOK TO FALL NEAR THE MRNG RUSH SO IMPACTS
SHOULD BE EXPECTED.

BY 12Z MON...THE CWA WILL BE SANDWICHED BETWEEN A 970S LOW OVER
THE UPR GREAT LAKES...AND A 1030S HIGH OVER THE ATLANTIC. THIS
WILL TRANSLATE INTO STRONG SLY FLOW. THE GFS HAS H975 WINDS OVER
50KT FOR MOST OF LI...WHICH IS CONCERNING. HAVE MIXED DOWN 80
PERCENT OF THIS FOR THE FCST AND ISSUED A WIND ADVY FOR ALL OF
LI...INCLUDING BROOKLYN AND QUEENS. THERE IS THE POTENTIAL THAT
THE ADVY MAY NEED TO BE EXPANDED NWD INTO CSTL CT IF DEEPER MIXING
OCCURS.

THE CORE OF THE STRONGEST WINDS ALOFT SHIFT EWD THRU THE DAY...SO
ONLY KEPT THE WRN PORTION OF THE ADVY THRU THE MRNG. SUFFOLK
COUNTY FOR THE ENTIRE DAY.

THE HIGHER ELEVATIONS WILL NEED TO BE MONITORED FOR LOCALLY
HIGHER GUSTS.

RECORD HIGH TEMPS STILL POSSIBLE.

&&

.SHORT TERM /MONDAY NIGHT/...
THE ASSOCIATED CDFNT COMES THRU OVERNIGHT. THIS USHERS THE MORE
HUMID AIRMASS OFFSHORE. THE PRES GRAD STILL STAYS UP SO IT WILL
REMAIN WINDY THRU THE NGT. SPEEDS HOWEVER WILL REMAIN BLW ADVY
CRITERIA WITH THE LOW APPROACHING LABRADOR. A FEW SHWRS ARE
POSSIBLE WITH THE FROPA. THE NAM HAS BEEN VERY CONSISTENT WITH
THIS SUGGESTION. AS A RESULT...MAINTAINED LOW CHCS FOR SHWRS FOR
THE PERIOD.

WITH THE COLD AIR LAGGING BEHIND AND WINDS KEEPING THE LLVLS
MIXED...LOW TEMPS EXPECTED TO BE A SOLID 10 DEGREES OR MORE ABV
AVG.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
TRANQUIL AND NEAR SEASONABLE TEMPS ON TUES AS A WEAK COLD FRONT
PASSES THROUGH THE REGION AND HIGH PRESSURE BRIEFLY BUILDS IN ITS
WAKE TUES NIGHT.

POTENTIAL CONTINUES TO INCREASE FOR A COASTAL STORM WITH SNOW...RAIN
AND WIND TO IMPACT THE REGION WED/WED NIGHT...BUT SPREAD REMAINS
MODERATE IN TERMS OF EXACT TRACK OF THIS SYSTEM.

FORECAST SENSITIVITY BASED ON SBU CSTAR ANALYSIS FOR THIS SYSTEM
LIES IN DEVELOPMENT OF TROUGH OVER THE EPAC OVER THE NEXT 48
HRS...AND RESULTANT DOWNSTREAM STRENGTH OF WEST COAST RIDGING AND
ULTIMATELY STRENGTH OF EAST COAST TROUGHING FOR MIDWEEK.
OPERATIONAL/ENSEMBLE MODEL ANALYSIS REVEAL MID/UPPER LEVEL MODEL
FIELDS IN GOOD AGREEMENT OVER THE NEXT 48 HOURS INITIALLY WITH
PHASING NORTHERN STREAM AND PAC ENERGY DIVING DOWN THE BACKSIDE OF
DEEP CENTRAL US TROUGHING...WITH THIS ENERGY THEN SWINGING UP THE
COAST WED AND INTERACTING WITH YET ANOTHER PIECE OF NORTHERN STREAM
SHORTWAVE ENERGY DIVING THROUGH THE MID-MISSISSIPPI RIVER VALLEY. IT IS
WITH THIS SECOND INTERACTION...AFTER 48 HRS...THAT MODELS DIVERGE
ENOUGH TO AFFECT STRENGTH AND ORIENTATION OF THE PHASED SHORTWAVE
ENERGIES AS THEY PIVOT THROUGH THE NE WED NIGHT/EARLY THU. THIS IS
RESULTING IN MINOR TIMING DIFFERENCES WITH THE COASTAL LOW...BUT
MAINLY TRACK DIFFERENCES. THE RANGE OF OPERATIONAL SOLUTIONS ON
TRACK OF COASTAL LOW ARE...THE 12Z ECMWF CONTINUING TO TREND WEST
AND TRACKING ACROSS LI WED NIGHT...TO THE 12Z NAM/CMC TRENDING WEST
AND PROJECTING WELL EAST OF BENCHMARK...AND 12Z GFS CONSISTENTLY
NEAR THE 40/70 LAT/LON.

WITH THIS SPREAD HAVE CONTINUED TO PLAY A MIDDLE OF THE ROAD TRACK
BETWEEN CMC/GEFS/ECMWF ENSEMBLE MEANS...WHICH WOULD TRACK LOW
PRESSURE NEAR TO JUST INSIDE THE 40/70 LAT/LON BENCHMARK WED NIGHT.
WITH ONLY A MARGINALLY COLD AIRMASS TO START...THIS TRACK WOULD
BRING MAINLY RAIN TO LI/SE CT...RAIN/SNOW MIX FOR NYC/NJ METRO AND
SW CT...AND MAINLY SNOW WELL N&W OF NYC...CHANGING TO ALL SNOW WED
NIGHT FOR MOST IF NOT ALL OF THE REGION AS THE LOW DEEPENS AND TRACK
NORTH. THIS MESHES FAIRLY WELL WITH WPC...WITH A LOW PROBABILITY OF
SEEING WARNING LEVEL SNOW RELEGATED TO INTERIOR PORTIONS OF NE
NJ...LOWER HUDSON VALLEY..AND SW CT...AND ADVISORY LEVEL SNOW
POSSIBLE INTO NYC METRO AND COASTAL SW CT SUN NIGHT. CONFIDENCE IN
THESE VALUES IS LOW TO MODERATE AT THIS POINT BASED ON ABOVE
MENTIONED SPREAD. PREDICTABILITY TOO LOW WITH THIS DAY 4 EVENT FOR A
DETERMINISTIC STORM TOTAL SNOW FORECAST.

ZONAL FLOW BUILDS IN BEHIND THE SYSTEM FOR FRI INTO THE WEEKEND WITH
GENERALLY QUIET AND TEMPS A FEW DEGREES SEASONABLE. A WEAK ALBERTA
CLIPPER MAY PASS TO THE NORTH ON SATURDAY WITH A FEW RAIN/SNOW
SHOWERS.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE DEPARTS TO THE EAST AS A WARM FRONT APPROACHES TONIGHT.

VFR THROUGH AROUND 03-05Z TONIGHT. RAIN WITH IFR CIGS/VSBY DEVELOPS
SHORTLY THEREAFTER. LIFR AT TIMES IN RAIN POSSIBLE 9-14Z. CANNOT
RULE OUT THUNDER AROUND THIS TIME FRAME AS WELL...ESPECIALLY EAST
OF NYC METRO.

IFR CONDITIONS LIKELY LINGER THROUGH THE MORNING MONDAY...ALTHOUGH
THE MODERATE/HEAVY RAIN WILL TAPER OFF TO LIGHT ISOLATED SHOWERS.

LIGHT S WINDS INTO THE EVENING TURN TOWARD THE SE.

LOW LEVEL WIND SHEAR IS LIKELY LATE TONIGHT INTO EARLY MONDAY
MORNING WITH WINDS AT 2000FT RANGING FROM 50-65 KT.

SURFACE WINDS TURN BACK TO THE SOUTH/SOUTHWEST BY 10-13Z. SPEEDS
INCREASE QUICKLY TO 15 TO 25KT WITH GUSTS 25 TO 35 KT. A FEW COASTAL
GUSTS COULD REACH 40 KT.

.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON...IMPROVING CONDITIONS. SOUTH/SOUTHWEST WINDS
AROUND 20 KT WITH 25-35 KT GUSTS.
.MONDAY NIGHT...VFR. WINDS SHIFT TO THE WEST AT 10-15 KT.
.TUESDAY...VFR. WSW WINDS 15-20 KT WITH 20-30 KT GUSTS.
.TUESDAY NIGHT...DIMINISHING WINDS. SUB-VFR CIGS POSSIBLE LATE.
.WEDNESDAY-WEDNESDAY NIGHT...LOW TO MODERATE CONFIDENCE FORECAST
WITH PASSAGE OF COASTAL LOW. ACCUMULATING SNOW THREAT POSSIBLE FOR
THE INTERIOR...BUT ACCUMULATING SNOW COULD OCCUR CLOSER TO THE COAST
DURING WED NIGHT BASED ON TRACK OF LOW. STRONG WINDS POSSIBLE
DEPENDING ON TRACK OF LOW AS WELL.
.THURSDAY...BECOMING VFR. LINGERING RAIN/SNOW SHOWERS POSSIBLE EARLY.
GUSTY WINDS POSSIBLE AS WELL.
.FRIDAY...VFR WITH GUSTY NW WINDS.

&&

.MARINE...
SEAS ON THE ERN OCEAN REMAIN IN THE 5-7 FT RANGE...SO MAINTAINED
THE SCA TIL 23Z.

STRONG PRES GRAD SETS UP LATE TNGT ALLOWING FOR SLY FLOW THRU MON
NGT. GALES DEVELOP LATE TNGT AND CONTINUE THRU MON. WINDS DIMINISH
LATE MON NGT FROM W TO E. THE GALE WAS EXTENDED FOR THE ERN
WATERS...AND MAY NEED TO BE EXTENDED FOR THE REMAINING WATERS BASED
ON THE EXACT TIMING AND STRENGTH OF THE SYS.

SCA CONDITIONS CONTINUE THROUGH TUESDAY WITH A TIGHT WNW
GRADIENT...FOLLOWED BY A RELATIVELY BRIEF PERIOD OF SUB-SCA
CONDITIONS LIKELY TUE NIGHT THROUGH WEDNESDAY MORNING AS HIGH
PRESSURE NOSE IN.

SCA CONDITIONS THEN LIKELY WED AFT THRU THU AS A COASTAL STORM
AFFECTS THE WATERS. POTENTIAL EXISTS FOR MARGINAL GALE CONDS ON THE
EASTERN WATERS WED NIGHT AS LOW PRESSURE MAKES ITS CLOSEST APPROACH
TO THE REGION. SCA CONDS POSSIBLE ON THE OCEAN WATERS THROUGH FRIDAY
DUE TO RESIDUAL SWELLS AND TIGHT OFFSHORE GRADIENT.

&&

.HYDROLOGY...
AROUND AN INCH OF RAIN IS EXPECTED LATE TNGT INTO MON. MINOR URBAN
FLOODING WILL BE POSSIBLE...WITH IMPACTS LIKELY AROUND THE TIME
OF THE MRNG COMMUTE.

INCREASING POTENTIAL EXISTS FOR 1/2 TO 1 INCH OF PRECIPITATION WED
INTO WED NIGHT. SOME PORTION OF THIS SHOULD FALL IN THE FORM OF
SNOW...PARTICULARLY ACROSS AREAS N&W OF THE NYC METRO.

&&

.TIDES/COASTAL FLOODING...
SOME OF THE MOST VULNERABLE SPOTS COULD TOUCH MINOR THRESHOLDS
DURING THE MON MRNG CYCLE. A STATEMENT IS THE MOST LIKELY SCENARIO
ATTM. AN UPDATE WILL BE ISSUED THIS EVE. SOME MINOR BEACH EROSION
IS POSSIBLE ON THE ATLANTIC COAST WITH SURF IN THE 5-8FT RANGE.

&&

.CLIMATE...
RECORD HIGH TEMPERATURES FOR MONDAY 24 NOVEMBER...

LOCATION........RECORD/YEAR.....FORECAST HIGH

NEWARK..............75/1979..........71
BRIDGEPORT..........63/1979..........65
CENTRAL PARK........73/1979..........69
LAGUARDIA AIRPORT...68/1999..........70
JFK AIRPORT.........63/2001*.........68
ISLIP...............63/2001..........66

* ALSO OCCURRED IN PREVIOUS YEARS

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY FROM 4 AM TO 11 AM EST MONDAY FOR NYZ075-176>179.
     WIND ADVISORY FROM 4 AM TO 6 PM EST MONDAY FOR NYZ078>081.
NJ...NONE.
MARINE...GALE WARNING FROM 1 AM TO 6 PM EST MONDAY FOR ANZ330-335-338-
     340-345.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
     353.
     GALE WARNING FROM 1 AM MONDAY TO 6 AM EST TUESDAY FOR ANZ350-
     353-355.

&&

$$
SYNOPSIS...JMC/NV
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...NV
AVIATION...PW
MARINE...JMC/NV
HYDROLOGY...JMC/NV
TIDES/COASTAL FLOODING...JMC
CLIMATE...






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