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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 111748
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1248 PM EST WED DEC 11 2013

.SYNOPSIS...
STRONG HIGH PRESSURE BUILDS IN FROM THE SOUTH AND WEST TODAY. A
COLD FRONT WILL TRACK ACROSS THE AREA THIS EVENING FOLLOWED BY
ANOTHER OF HIGH PRESSURE FOR THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
MINOR ADJUSTMENTS MADE TO TEMPS TO REFLECT LATEST OBS.
OTHERWISE...FORECAST REMAINS ON TRACK.

TRANQUIL BUT COLD CONDS EXPECTED TODAY AS HIGH PRES BUILDS IN FROM
THE SW. STRONG SUBSIDENCE ALOFT WILL ALLOW FOR MOSTLY SUNNY SKIES
TODAY...WITH PERHAPS JUST A FEW-SCT STRATO CU AROUND THIS AFTN.
HIGHS WILL ONLY REACH LOW TO MID 30S THIS AFTN...WHICH IS A GOOD
10 DEGREES BELOW NORMAL.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FAIRLY BENIGN CONDS WILL CONTINUE THROUGH THU...ALTHOUGH IT WILL
REMAIN COLD. A COLD FRONT WILL MOVE ACROSS THE AREA THIS
EVENING...ALTHOUGH MOISTURE IS LACKING AND NOT EXPECTING TO SEE
ANY PRECIP UNTIL PERHAPS IT NEARS THE COAST AND CAN TAP INTO
ATLANTIC/SOUND MOISTURE. DECENT SHORTWAVE PASSING ALOFT...SO THIS
MAY BE ENOUGH LIFT FOR SOME FLURRIES ON LONG ISLAND.

A COLDER AIR MASS WILL THEN FILTER INTO THE REGION WITH H85 TEMPS
ONLY RANGING BETWEEN -16 TO -18C ON THU. VERY COLD TONIGHT WITH
PERHAPS A PERIOD OF GUSTY WINDS FOLLOWING THE FROPA. WINDS SHOULD
REMAIN HIGH ENOUGH OVERNIGHT TO KEEP THE BOTTOM FROM FALLING OUT
TOWARDS MORNING. EXPECT LOWS IN THE TEENS INLAND TO LOWER 20S AT
THE COAST WITH WIND CHILLS IN THE SINGLE DIGITS AND TEENS
RESPECTIVELY. HIGHS ON THU WILL STRUGGLE TO REACH 30 DEGREES AT
THE COAST...WITH ONLY MID TO UPPER 20S INLAND AND WIND CHILLS IN
THE TEENS ACROSS THE AREA.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MODELS WERE IN REASONABLE AGREEMENT THURSDAY NIGHT THROUGH
FRIDAY NIGHT...SO USED A BLEND OF THE NAM/GFS/ECMWF/SREF FOR THE
FORECAST IN THAT TIME FRAME.

A 700 HPA SHORTWAVE CROSSES THE AREA THURSDAY NIGHT...HOWEVER WITH
THE LOW LEVELS PROGGED TO BE DRY - WENT WITH A DRY FORECAST KEEPING
PRECIPITATION OFFSHORE (IN THIS CASE FAVORING THE NAM/SREF OVER THE
GFS/ECMWF WHICH WOULD SUGGEST SLIGHT CHANCE  TO CHANCE POPS OVER SE
ZONES). FOR LOWS THURSDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE
WITH VALUES AROUND 5 DEGREES BELOW NORMAL. WIND CHILLS LATE THURSDAY
NIGHT WILL RUN FROM THE UPPER SINGLE DIGITS TO AROUND 15 - COLDEST N
INTERIOR AND PINE BARRENS - HIGHEST NYC METRO.

AN ARCTIC FRONT PUSHES THROUGH FRIDAY AFTERNOON/EVENING ALLOWING FOR
A REINFORCING SHOT OF COLD AIR TO PUSH INTO THE REGION. NOTING
CONTINUED DRY LOW LEVELS AND NO SHORTWAVES FORECAST TO PASS ALOFT -
HAVE KEPT THE FRONTAL PASSAGE DRY...THOUGH CANNOT COMPLETELY RULE
OUT SOME FLURRIES/LOCALIZED -SHSN AS IT GOES BY AND IN ITS IMMEDIATE
WAKE. FOR HIGHS FRIDAY USED A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES AND A MIX DOWN FROM 950 HPA...EXCEPT 925 HPA
WELL INLAND - EXPECT READINGS TO BE AROUND 15 DEGREES BELOW
NORMAL...WITH STEADY OR FALLING TEMPERATURES IN THE AFTERNOON. WIND
CHILLS DURING THE DAY SHOULD NOT GET ABOVE THE TEENS. FOR LOWS
FRIDAY NIGHT USED A BLEND OF MEX/MEN/EKD/ECM/ECE/WPC GUIDANCE WITH
LOWS 5-10 DEGREES BELOW NORMAL AND WIND CHILLS MAINLY FROM THE MID
TEENS TO LOWER 20S...EXCEPT AROUND 10 DEGREES OVER THE EASTERN 2/3
OF THE CWA WHERE THE WIND WILL BE A TAD HIGHER (AROUND 10 MPH VICE 5
MPH OR LESS).

FROM SATURDAY THROUGH THROUGH SUNDAY NIGHT THERE ARE DIFFERENCES
BETWEEN THE MODELS IN THEIR HANDLING OF A COASTAL STORM. BECAUSE THE
GFS HISTORICALLY HAS HAD A BIAS OF BEING TO WEAK WITH AND TO QUICK
TO ERODE DAMMING HIGHS...AND GIVEN THAT EVEN IT KEEPS THE CORE OF
THE HIGH TO OUR N AND DOES NOT HAVE IT RETREATING - ANOTHER SIGN
THAT WORKS AGAINST ITS IDEA OF WEAKENING THE DAMMING OVER THE AREA.
BECAUSE OF THIS...THE GFS LOW TRACK IS TOO CLOSE TO THE COAST AS IT
DOES NOT ALLOW FOR SUFFICIENT BLOCKING OF ITS NORTHWARD PROGRESS BY
THE HIGH TO THE N. FOR THIS REASON HAVE LEANED HEAVILY TOWARDS THE
ECMWF IN THIS TIME FRAME - IT ALSO HISTORICALLY DOES FAIRLY WELL
WITH DAMMING HIGHS IN ADDITIONS TO GENERALLY BEING THE BETTER
PERFORMING MODEL IN THIS TIME FRAME.

BASED ON THIS MODEL CHOICE HAVE THE POTENTIAL FOR A SIGNIFICANT
WINTER STORM TO IMPACT THE AREA FROM MAINLY SATURDAY AFTERNOON
THROUGH SUNDAY...WITH IT PASSING NEAR THE 40N/70W BENCH MARK DURING
THE DAY ON SUNDAY. MORE CONFIDENT OF ALL SNOW INLAND THAN AT THE
COAST...WITH THE SURFACE WIND FORECAST TO GO E-ESE SATURDAY
AFTERNOON/NIGHT - USUALLY THIS WILL BRING MOST OF LONG ISLAND AND
NYC AS WELL AS AT LEAST COASTAL SE CT TO ALL RAIN. HOWEVER...THE
FACT THAT AN ARCTIC AIR MASS WILL BE IN PLACE AND RE-ENFORCED TO THE
N MEANS THAT IF THE FLOW IS BACKED MORE THAN CURRENTLY FORECAST DUE
TO ISALLOBARIC INFLUENCES - COULD END UP STAYING MAINLY SNOW OVER
COASTAL AREAS AS WELL. STILL QUITE A BIT OF UNCERTAINTY ON TRACK OF
THE SYSTEM SO THIS FORECAST COULD VERY WELL CHANGE. FOR TEMPERATURES
SATURDAY-SUNDAY USED A BLEND OF ALL AVAILABLE GUIDANCE WITH ECMWF
2-METER TEMPERATURES - FOR NOW ECMWF 2-M TEMPERATURES APPEARED TOO
COLD - SO USED OTHER GUIDANCE TO TEMPER. EXPECT TEMPERATURES TO BE
BELOW NORMAL BASED ON THE ABOVE THINKING.

IN ADDITION TO THE ISSUES WITH PRECIPITATION...IT COULD BE QUITE
WINDY WITH THIS STORM - TOO MUCH UNCERTAINTY TO SPECIFY IF WIND
RELATED HEADLINES COULD BE NEEDED - BUT IT IS REASONABLE TO SAY THAT
POSSIBILITY IS WITHIN THE REASONABLE REALM OF
POSSIBILITIES...ESPECIALLY FOR COASTAL AREAS.

REASONABLE MODEL AGREEMENT RETURNS FROM MONDAY INTO TUESDAY SO USED
A ECMWF/GFS BLEND IN THIS TIME FRAME.

FOR NOW EXPECT PRECIPITATION TO CUTOFF FAIRLY RAPIDLY AS THE STORM
PULLS AWAY - SO WENT DRY SUNDAY NIGHT - AND CONTINUED WITH THAT DRY
FORECAST INTO TUESDAY AS 700-500 HPA NORTHERN STREAM RIDGE TRANSITS
THE AREA. USED A BLEND OF ALL AVAILABLE GUIDANCE FOR TEMPERATURES
WITH BELOW NORMAL VALUES FORECAST.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
A SLIGHT DECREASE OCCURS IN PRESSURE GRADIENT AS HIGH PRESSURE TO
SOUTHWEST WEAKENS AND MOVES OFFSHORE. A WEAK COLD FRONT MOVES
THROUGH TONIGHT. VFR EXPECTED WITH A FEW SNOW FLURRIES LATE
TONIGHT NEAR THE TIME OF THE FRONTAL PASSAGE.

HIGH CONFIDENCE IN VFR CONDITIONS AND GUSTY W FLOW. GUST MAGNITUDE
LOWERS A LITTLE THIS EVENING BUT COULD BE A FEW KTS HIGHER THAN
FORECAST WITH THE FRONTAL PASSAGE. FLOW BECOMES MORE NW TONIGHT
INTO THU MORNING.

     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST
AND HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

KLGA FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST
AND HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

KEWR FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST
AND HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES  SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST
AND HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

KHPN FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST
AND HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

KISP FCSTER COMMENTS: OVERALL MODERATE CONFIDENCE IN WIND FORECAST AND
HIGH CONFIDENCE IN CATEGORY FORECAST. WIND GUSTS COULD
OCCASIONALLY PEAK A FEW KTS HIGHER THAN FORECAST AND END TIME FOR
GUSTS COULD BE +/- 1-2 HOURS FROM FORECAST.

.OUTLOOK FOR 18Z THU THROUGH MONDAY...
.THU AFTN...VFR. WIND GUSTS DIMINISHING WITH WIND DIR BECOMING W.
.FRI...VFR.
.SAT-SUN...IFR IN WINTRY PCPN. SIGNIFICANT SNOWFALL POSSIBLE
INLAND...AND SNOW CHANGING TO RAIN OR A RAIN/SNOW MIX AT THE
COAST. E-NE WINDS G30-35KT SAT NIGHT INTO SUNDAY.
.MON...VFR.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
SCA CONTINUES ON ALL WATERS BY WESTERN SOUND AND NEW YORK HARBOR
WITH WINDS DIMINISHING. SEAS ON THE EASTERN OCEAN WATERS WILL
LIKELY REMAIN AOA 5 FT FOR MUCH IF NOT ALL OF THE DAY AND GUSTS
WILL TAKE A BIT LONGER TO SUBSIDE AS WELL ON THE EASTERN WATERS.
SCA CONDS ARE EXPECTED TO BE MET AGAIN THIS EVE...THEREFORE HAVE
OPTED FOR SIMPLICITY AND HAVE EXTENDED THE ADVY FOR THE EASTERN
SOUND/BAYS AND OCEAN WATERS THROUGH TONIGHT. WESTERN LI SOUND...NY
HARBOR AND SOUTH SHORE BAYS ARE MARGINAL REACHING SCA CONDS
TONIGHT AND THERE IS ALSO ENOUGH OF A LULL BETWEEN EVENTS FOR IT
TO BE TAKEN DOWN LATER THIS MORNING AND AFTN.

SCA CONDS MAY LINGER INTO EARLY THU MORNING ON THE OCEAN
WATERS...BUT ARE EXPECTED TO SUBSIDE BY MIDDAY.

SCA CONDITIONS ARE LIKELY ON THE COASTAL OCEAN WATERS THU NIGHT
THROUGH AT LEAST FRIDAY...AND POSSIBLY INTO FRI EVENING E OF FIRE
ISLAND INLET AND THROUGH ALL OF FRI NIGHT E OF MORICHES INLET.
FOR THE REMAINDER OF THE WATERS...ITS LIKELY SCA WIND GUSTS WILL
RETURN LATE THURSDAY NIGHT AND CONTINUE THROUGH FRIDAY...WITH SUB-
SCA CONDITIONS FRIDAY NIGHT.

ALL WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS SATURDAY
MORNING...WINDS THEN INCREASE WITH THE APPROACH/PASSING OF A STRONG
COASTAL LOW SATURDAY NIGHT/SUNDAY. AT LEAST GALE GUSTS ARE LIKELY ON
ALL WATERS BY LATE SATURDAY NIGHT AND SHOULD PERSIST THROUGH SUNDAY.
WILL HIGHLIGHT THIS POTENTIAL IN THE HWO. THERE IS A SMALL CHANCE
FOR STORM FORCE WINDS LATE SATURDAY NIGHT/SUNDAY OVER MAINLY THE
COASTAL OCEAN WATERS DEPENDING ONT HE EXACT TRACK/STRENGTH OF THE
STORM - BUT THIS POTENTIAL IS TO LOW TO MENTION IN THE HWO AT THIS
TIME.
-- End Changed Discussion --

&&

.HYDROLOGY...
THERE IS THE POTENTIAL FOR SIGNIFICANT PRECIPITATION THIS WEEKEND
IN ASSOCIATION WITH A COASTAL LOW PRES SYSTEM.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ330-340-
     350-353-355.
-- End Changed Discussion --

&&

$$