Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 270842
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
442 AM EDT MON OCT 27 2014

.SYNOPSIS...
A HIGH PRES RIDGE BUILDS OVER THE TRI-STATE REGION TODAY...AND
OFFSHORE ON TUE. A COLD FRONT MOVES ACROSS LATE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE FOLLOWS THROUGH THURSDAY WITH LOW
PRESSURE DEVELOPMENT SOUTHEAST OF THE REGION FRIDAY...SWINGING
INTO THE CANADIAN MARITIMES AND DEEPENING FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW CLOUDS ENHANCED BY MOISTURE OFF LAKE ONTARIO HAVE BEEN SLOW TO
ERODE...PARTICULARLY ACROSS THE HUDSON VALLEY TO CT AND ERN LI.
THE CLOUDS ARE LIKELY TRAPPED BELOW THE SUBSIDENCE INVERSION...THE
12Z RAOB SHOULD VERIFY THIS. THIS SETUP WOULD LIMIT THE CLOUD
DISSIPATION TIL A FEW HOURS AFT SUNRISE

UPPER RIDGE BUILDS IN TODAY SO DRY WX. TEMPS ALOFT WARM BUT LGT
WINDS WILL NOT BE CONDUCIVE TO DEEP MIXING. MIXING TO H75 WOULD
YIELD LOWER 80S...BUT THE CWA WILL ONLY MAX OUT AROUND 60.

HIGH CLOUDS FROM SUBTROPICAL PACIFIC TAP AND MIDWEST CONVECTIVE
DEBRIS SPREADS INTO THE REGION LATE THIS AFTERNOON AND TONIGHT.
OUTSIDE OF THAT...WINDS WILL BE LGT AND ATTEMPT TO VEER THE SW BY
TUE MORNING. EXPECT THE CLOUDS TO KEEP TEMPS FROM COMPLETELY
BOTTOMING OUT...SO BLENDED IN THE WARMER GMOS25 WITH THE MET.

&&

.SHORT TERM /TUESDAY/...
A WARMING TREND AS WINDS VEER TO THE SW AND PICK UP ON THE
BACKSIDE OF THE HIGH. HIGH CLOUDS BKN-OVC AT TIMES...BUT BECAUSE
OF OPACITY FCST INDICATES MOSTLY SUNNY. UPSTREAM COLD FRONT WILL
BE APPROACHING...SO THIS COULD ALLOW FOR A LITTLE COMPRESSIONAL
HEATING WHICH COULD BOOST TEMPS A FEW DEGREES ABOVE
FCST...ESPECIALLY ACROSS NJ AND THE INTERIOR. MOISTURE AND FORCING
IN THE VICINITY OF THE FRONTAL BOUNDARY STILL W OF THE CWA SO
CONTINUED DRY WEATHER.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
TUESDAY NIGHT INTO WEDNESDAY...SHORTWAVE AND SFC LOW MOVE NORTHEAST
THROUGH ONTARIO AND QUEBEC. AN ASSOCIATED COLD FRONT MOVES ACROSS
LATE TUESDAY NIGHT INTO WEDNESDAY.

THE JET STREAM MOVES INTO THE REGION AND EVENTUALLY JUST SOUTH OF
THE REGION WEDNESDAY NIGHT AS SHORTWAVE EXITS NORTHEAST INTO
CANADIAN MARITIMES AND SFC LOW SLOWLY MOVES NORTH IN SOUTHEAST
CANADA AND WEAKENS. THE COLD FRONT MOVES FARTHER EAST OF THE AREA
AND OFFSHORE.

THE RAIN SHOWERS ASSOCIATED WITH THE FRONT START TO MOVE IN LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING...THOUGH COULD DISSIPATE WITH
EASTWARD PROGRESS DURING WEDNESDAY AS THE FRONT MOVES ACROSS THE
REGION. THIS WILL BE ANOTHER MOISTURE LIMITED FRONT. THE GFS AND
NAM MODELS HAVE PRETTY GOOD AGREEMENT REGARDING THIS.
HOWEVER...THE CANADIAN AND ECMWF SHOW ENHANCEMENT OF PRECIP ALONG
THE FRONT FROM THE DELMARVA THROUGH LONG ISLAND AND SOUTHERN
CONNECTICUT WEDNESDAY NIGHT WITH THESE MODELS ALREADY SHOWING SOME
WEAK LOW DEVELOPMENT ALONG THE SOUTHERN END OF THE FRONT.
THEREFORE...KEPT SHOWERS IN THE FORECAST THROUGH WEDNESDAY
NIGHT...MAINLY NYC...LONG ISLAND...AND SOUTHEAST CONNECTICUT.

WEAK SFC HIGH PRESSURE MOVES IN PLACE THURSDAY AND THURSDAY NIGHT
BUT FLOW ALOFT WILL BECOME AMPLIFIED WITH A TROUGH SHARPENING AND
APPROACHING THE REGION AS JET STREAM REMAINS SOUTH OF THE REGION.
COLD FRONT WILL BE WELL OFFSHORE WITH WEAK LOW PRESSURE DEVELOPING
ALONG SOUTHERN END OF FRONT SOUTHEAST OF THE CAROLINAS. DRY WEATHER
WILL BE IN PLACE.

MODELS HAVE GOOD AGREEMENT WITH TROUGH TO WEST OF REGION FRIDAY
AND SFC HIGH PRESSURE IN CENTRAL U.S. BUT THE GFS IS DISTINGUISHED
IN THAT IT SHOWS A LOW IN THE NORTHEAST SO SFC FEATURES HAVE
GREATER UNCERTAINTY. THE UNCERTAINTY HAS RIPPLE EFFECTS AS THE
TROUGH APPROACHING CAN BE TRACED BACK TO UPSTREAM RIDGE AND WEST
OF THERE...YET ANOTHER TROUGH. SO OVER THE NEXT FEW DAYS...THERE
WILL LIKELY BE SOME TIMING CHANGES OF PRECIP AND TEMPERATURE
VARIANCES FROM FORECAST TO FORECAST AS THERE ARE MANY FACTORS THAT
HAVE TO BECOME BETTER RESOLVED WITH UPSTREAM FEATURES IN ADDITION
TO ONES NEAR THE REGION.

THE SHORTWAVE AND JET STREAM FEED MOISTURE INTO THE OFFSHORE FRONT
AND LOW DEVELOPING ALONG THE SOUTHERN END OF IT. WITHOUT MUCH
SIGNIFICANT EASTWARD PROGRESS OF SFC HIGH PRESSURE...A BLOCKING
PATTERN WILL EMERGE AND SHOWERS COULD DEVELOP IN WESTERN PERIPHERY
OF CYCLONIC FLOW ALL IN ASSOCIATION WITH DEEP LOW PRESSURE
DEVELOPING EAST OF NOVA SCOTIA IN THE PERIOD OF MAINLY FRIDAY NIGHT
THROUGH SATURDAY NIGHT. AT NIGHT...TEMPERATURES ARE FORECAST TO BE
COLD ENOUGH FOR SOME SNOW SHOWERS NORTH AND WEST OF NYC. THE
SOURCES OF THE LOW PRESSURE WILL BE FROM THE CAROLINAS AND ALSO
ANOTHER FROM SOUTHEAST CANADA.

A STEEP PRESSURE GRADIENT WILL BE ESTABLISHED BETWEEN THE HIGH TO
THE WEST OF THE REGION AND LOW PRESSURE EAST OF NOVA SCOTIA FOR
NEXT WEEKEND. THEREFORE...MORE GUSTY NORTHERLY FLOW FOR NEXT
WEEKEND. THE UPPER LEVEL PATTERN REMAINS CONSISTENT WITH
AMPLIFICATION WITH SHORTENING WAVELENGTH OF UPPER LEVEL TROUGH AND
JET STREAM STILL SOUTH OF REGION.

THE FEATURES TRANSLATE EAST SUNDAY INTO EARLY NEXT WEEK WITH A
HIGH PRESSURE RIDGE MOVING IN FROM THE WEST.

CONCERNING TEMPERATURES...WARMING TREND COMES TO A CLOSE
WEDNESDAY NIGHT...WITH A COLDER AIRMASS MOVING IN BEHIND THE COLD
FRONT. TEMPERATURES WILL BE CLOSE TO NORMAL THURSDAY AND THURSDAY
NIGHT WITH LOWER THAN NORMAL TEMPERATURES THROUGH THE REMAINDER OF
THE FORECAST PERIOD.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE BUILDS OF THE SOUTHEAST AND MID ATLANTIC COASTS INTO
FRIDAY EVENING.

VFR. CEILINGS AROUND 5000 FT LINGER ON/OFF AT KGON THROUGH
POSSIBLY 10Z.

WNW WINDS AROUND 10 KT EARLY THIS MORNING. EXCEPTION IS AT
KSWF/KISP WHERE WINDS LIGHT AND VARIABLE AND KGON WHERE WINDS
LESS THAN 10 KT. WINDS BECOME WNW-NW THROUGHOUT AROUND 10 KT BY
MID MORNING...WITH OCCASIONAL GUSTS TO 15-20KT POSSIBLE 12-18Z AT
ALL TERMINALS. HOWEVER RELATIVELY LOW CONFIDENCE IN OCCURRENCE
AND LIMITED DURATION AT ANY GIVEN POINT DO NOT WARRANT PLACING IN
TAFS AT THIS TIME. WINDS BACK TO THE W-WSW BY EARLY
EVENING...THEN BECOME LIGHT AND VARIABLE THROUGH THE EVENING.

...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: WINDS MAINLY JUST TO THE LEFT OF 300
TRUE/310 MAGNETIC. HOWEVER...THERE WILL BE OCCASIONS WHERE WINDS
REACH OR GO 10 TO 20 DEGREES TO THE RIGHT OF 300 TRUE/310
MAGNETIC. LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO 15-20KT FROM
LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN WIND
DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

KLGA FCSTER COMMENTS: WINDS MAINLY JUST TO THE LEFT OF 300
TRUE/310 MAGNETIC. HOWEVER...THERE WILL BE OCCASIONS WHERE WINDS
REACH OR GO 10 TO 20 DEGREES TO THE RIGHT OF 300 TRUE/310
MAGNETIC. LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO 15-20KT FROM
LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN WIND
DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

KEWR FCSTER COMMENTS: WINDS MAINLY TO THE LEFT OF 300 TRUE/310
MAGNETIC. HOWEVER...THERE WILL BE BRIEF OCCASIONS WHERE WINDS
REACH OR GO 10 TO POSSIBLY 20 DEGREES TO THE RIGHT OF 300 TRUE/310
MAGNETIC. LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO 15-20KT FROM
LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN WIND
DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

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

KTEB FCSTER COMMENTS: LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO
15-20KT FROM LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN
WIND DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

KHPN FCSTER COMMENTS: LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO
15-20KT FROM LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN
WIND DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

KISP FCSTER COMMENTS: LOW-MODERATE CHANCE OF OCCASIONAL GUSTS TO
15-20KT FROM LATE MORNING INTO MID AFTERNOON. TIMING OF CHANGES IN
WIND DIRECTION AND SPEED COULD BE OFF +/- 1-3 HOURS.

.OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY.
.LATE MONDAY NIGHT-TUESDAY...VFR.
.TUESDAY NIGHT...MAINLY VFR. LLWS POSSIBLE SOUTHERN TERMINALS.
BRIEF PERIOD MVFR POSSIBLE IN ANY STRONGER -SHRA - MAINLY AFTER
MIDNIGHT.
.WEDNESDAY-WEDNESDAY NIGHT...MAINLY VFR. HOWEVER BRIEF PERIOD OF
MVFR OR LOWER POSSIBLE IN ANY STRONGER -SHRA. WINDS VEER WSW TO NW
WITH PASSAGE OF COLD FRONT. G15-20KT POSSIBLE.
.THURSDAY-FRIDAY...VFR.

&&

.MARINE...
WINS AND SEAS HAVE FALLEN BELOW SCA LEVELS...SO THE SCA HAS BEEN
CANCELLED. CONDITIONS BELOW SCA LEVELS THROUGH TONIGHT WITH HIGH
PRESSURE OVER THE WATERS. RETURN FLOW ON TUE AS THE HIGH DRIFTS E
OVER THE ATLANTIC...BUT WINDS AND SEAS LIKELY REMAIN BELOW SCA
LEVELS.

SOUTHERLY FETCH AHEAD OF COLD FRONT WILL KEEP SCA SEAS ON OCEAN TUE
NIGHT THROUGH MUCH OF WED NIGHT WITH SEAS FALLING BELOW SCA BEFORE
DAYBREAK THU. SEAS ARE FORECAST TO STAY BELOW SCA THEREAFTER UNTIL
SAT WHEN OCEAN SEAS OF AT LEAST 5-7 FT WILL BE POSSIBLE.

REGARDING WINDS...THERE COULD BE SOME SCA WIND GUSTS RIGHT AHEAD OF
THE COLD FRONT LATE TUE NIGHT. OTHER WATERS WILL BE BELOW SCA FOR
WINDS. THE OCEAN WILL REMAIN MARGINAL FOR SCA WINDS WITH GUSTS 20-25
KT WED AND WED NIGHT. OTHER WATERS CLOSER TO 20 KT. SUB SCA
THEREAFTER UNTIL FRIDAY NIGHT AND THE WEEKEND...WHICH LOOKS TO BE A
ROUGH PERIOD FOR THE AREA WATERS. GALES WILL BE POSSIBLE FOR THE
WEEKEND.

&&

.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD PRECIPITATION EXPECTED.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...JMC/JM
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JM
AVIATION...MALOIT
MARINE...JMC/JM
HYDROLOGY...JM





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