-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 221945
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
345 PM EDT TUE JUL 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE AS A COLD FRONT
APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS FROM
WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE
ON FRIDAY. THE HIGH WILL WEAKEN ON SATURDAY...THEN LOW PRESSURE
PASSING TO THE SOUTHEAST WILL IMPACT THE AREA SUNDAY INTO MONDAY.
AN ASSOCIATED COLD FRONT WILL APPROACH LATE DAY MONDAY...AND MOVE
ACROSS MONDAY NIGHT INTO TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SOME WEAK UPPER LEVEL ENERGY WILL SPILL OVER THE TOP OF THE RIDGE
ALONG THE NORTHEAST THIS EVENING. SOME WIDELY ISOLATED SHOWERS AND
POSSIBLE THUNDERSTORMS MAY DEVELOP EARLY IN THE EVENING HOURS...
MAINLY NORTH AND WEST OF NYC. WILL CAP POPS AT 20 PERCENT...AS NOT
EXPECTING MANY...IF ANY...STORMS. LATEST HRRR GUIDANCE CONTINUES
TO INDICATE SOME SHOWERS...MAINLY WEST OF THE HUDSON RIVER AND
INTO INTERIOR PORTIONS OF SW CT. ANY SHOWERS THAT DEVELOP WILL END
BETWEEN 9-10 PM.

WARM AND HUMID NIGHT ON TAP WITH LOWS IN THE 60S TO LOW 70S. THE
WARMEST TEMPS WILL OCCUR IN/AROUND NYC DUE TO THE URBAN HEAT
ISLAND EFFECT. SFC DEW POINTS WILL CLIMB THROUGH THE MID 60S AND
INTO THE UPPER 60S. CAN EXPECT PATCHY FOG TO DEVELOP AWAY FROM THE
CITY.

THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING WITH
ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
HOT AND INCREASINGLY HUMID AIR MASS REMAINS OVER THE AREA
WEDNESDAY. WITH HIGH PRES DEPARTING AND COLD FRONT APPROACHING
FROM THE WEST...SW FLOW INCREASES THROUGHOUT THE DAY...AND SFC
DEWPOINTS WILL RISE THROUGH THE 60S AND INTO THE LOWER 70S. MAX
TEMPS ON WEDNESDAY WILL TOP OFF IN THE LOWER 90S ACROSS NYC AND NE
NJ...AND WILL BE IN THE UPPER 80S TO NEAR 90 ELSEWHERE. TEMPS WILL
BE SIGHTLY COOLER NEAR THE COASTS. THE HEAT INDEX ON WEDNESDAY
WILL GENERALLY TOP OFF IN THE LOW TO MID 90S...EXPECT FOR NYC/NE
NJ...WHERE THE HEAT INDEX WILL BE IN THE MID TO UPPER 90S. SINCE
THE HEAT INDEX IN NYC WILL NOT REACH 95 FOR 2 CONSECUTIVE
DAYS...AND SINCE THE HEAT INDEX WILL REMAIN BELOW 100 ACROSS THE
CWA...WILL NOT ISSUE A HEAT ADVISORY.

AS COLD FRONT APPROACHES...SHOWERS AND THUNDERSTORMS WILL DEVELOP
NORTH AND WEST OF NYC IN THE AFTERNOON ALONG A PRE-FRONTAL TROUGH.
SHOWERS AND THUNDERSTORMS SPREAD EAST WEDNESDAY EVENING AND
WEDNESDAY NIGHT...AND THE BULK OF THE ACTIVITY SHOULD HOLD OFF
UNTIL WEDNESDAY NIGHT AS THE COLD FRONT PASSES THROUGH THE REGION.

WITH THE HEAT AND HUMIDITY...ML MUCAPE VALUES WILL RANGE FROM
1000-1500 J/KG DURING THE DAY...AND THEN WILL DROP TO AROUND 400
J/KG AT NIGHT WITH THE LOSS OF THE HEATING. 0-6 KM BULK SHEAR WILL
BE WEAK DURING THE DAY...AND THEN WILL RISE TO 25-35 KT AFTER 00Z
THURSDAY. CANNOT RULE OUT STRONG WINDS WITH ANY THUNDERSTORMS...
BUT PRIMARY THREAT WILL BE HEAVY RAIN DUE TO PWATS AROUND 2".
FLASH FLOODING OF LOW LYING AND POOR DRAINAGE AREAS IS POSSIBLE.
WILL NOT ISSUE A HAZARDOUS WEATHER OUTLOOK AS THE THREAT WILL NOT
BE WIDESPREAD.

SHOWERS AND THUNDERSTORMS TAPER OFF FROM WEST TO EAST WEDNESDAY
NIGHT AS THE COLD FRONT WORKS ITS WAY ACROSS THE REGION.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE SFC COLD FRONT SHOULD BE TO THE EAST THU MORNING...BUT WITH THE
H8 FRONT STILL YET TO MOVE ACROSS...A MID LEVEL TROUGH STILL WELL TO
THE WEST AND POTENTIAL FOR A WEAK SFC WAVE ALONG THE FRONT TO SLOW
ITS PROGRESS EVEN FURTHER...WILL HAVE LIKELY POP TO START ACROSS SE
CT AND ERN LONG ISLAND AND CHANCE ELSEWHERE...WITH CHANCES GRADUALLY
RAMPING DOWN DURING THE AFTERNOON AND EARLY EVENING. CONDS LOOK
MAINLY DRY FOR LATER THU NIGHT AND MORE SO INTO FRI AS HIGH PRESSURE
BUILDS FROM THE WEST.

THE HIGH SHOULD WEAKEN ON SAT AS FLOW ALOFT BECOMES MORE ZONAL.
AS LOW TO MID LEVEL MOISTURE RETURN COMMENCES...WITH PRECIP
EFFICIENCY INCREASING BACK TO OVER 1 INCH BY LATE DAY...AND AS MID
LEVEL SHORTWAVES APPROACH IN ZONAL FLOW...SHOULD START TO SEE
INCREASING CHANCES FOR SHOWERS/TSTMS BEGINNING LATE DAY SAT INTO
SAT NIGHT.

THE FLOW ALOFT SHOULD UNDERGO SIGNIFICANT AMPLIFICATION EARLY NEXT
WEEK AS AN UPPER RIDGE BUILDS IN THE WESTERN STATES AND A POTENT
SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA MERGES WITH AN UPPER
LOW OVER QUEBEC...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE
EASTERN STATES. THERE WILL BE GOOD CHANCES FOR SHOWERS/TSTMS...
ESPECIALLY SUNDAY NIGHT INTO MON MORNING AS AN ASSOCIATED WAVE OF
LOW PRESSURE PASSES JUST OFF TO THE SE...THEN LATE DAY MON INTO MON
NIGHT WITH THE APPROACH OF A COLD FRONT FROM THE WEST.

COULD SEE SOME LEFTOVER SHOWERS/TSTMS ON TUE MAINLY IN THE MORNING
AS THE COLD FRONT MOVES TO THE EAST...THEN DRIER AND SLIGHTLY COOLER
AIR ARRIVING THROUGH THE REST OF TUE INTO TUE NIGHT.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH
OF THE TAF PERIOD.

SEA BREEZE HAVE DEVELOPED THIS AFTERNOON AT KJFK/LGA. THE SEA BREEZE
SHOULD REACH KEWR BY 21Z. THIS WILL RESULT IN WIND DIRECTION AROUND
170-180 TRUE BY LATE AFTERNOON. WINDS DIMINISH TONIGHT...WITH MOST
SPOTS BECOMING LIGHT AND VARIABLE. SPEEDS INCREASE ONCE AGAIN ON
WEDNESDAY.

THERE IS A CHANCE OF SOME PATCHY FOG TONIGHT. HAVE INCLUDED SOME
TEMPOS FOR REDUCE VSBYS AFTER 08Z.

 ...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: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.

KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
GUSTS MAY BE OCCASIONAL THIS AFTERNOON.

KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER
TO 220 TRUE.

KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY
CLOSER TO 220 TRUE.

KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.

KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
GUSTS MAY BE OCCASIONAL.

.OUTLOOK FOR 18Z WED THROUGH SUN...
.WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE.
.WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN
SCT-NUMEROUS SHOWERS/TSTMS.
.THU NIGHT-SAT...VFR.
.SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE.

&&

.MARINE...
THE LOCAL ENHANCED SEA BREEZE IS RESULTING IN 15-20 KT WINDS
ACROSS NY HARBOR AND THE WESTERN OCEAN WATERS. NOT EXPECTING 25 KT
GUSTS...SO WILL NOT HOIST A BRIEF SMALL CRAFT ADVISORY.
OTHERWISE...SUB-SCA CONDS EXPECTED THROUGH TONIGHT. PATCHY FOG
WILL DEVELOP ON THE WATERS TONIGHT...REDUCING VSBY TO AS LOW AS 1
NM.

WINDS WILL INCREASE TO 15-20 KT ONCE AGAIN ON THE OCEAN WATERS
WEDNESDAY AFTERNOON AND TO 10-15 KT WITH 15-20 KT GUSTS ON THE
REST OF THE WATERS AHEAD OF AN APPROACHING COLD FRONT. CONVECTION
LIKELY WEDNESDAY NIGHT. SEAS WILL AVERAGE 2-4 FT ON THE OCEAN AND
AROUND 1 FT ELSEWHERE.

OUTSIDE OF TSTMS THU AND LATE DAY SAT HAVE HIGH CONFIDENCE IN
QUIET CONDS THU THROUGH SAT...THEN FCST UNCERTAINTY CREEPS IN
BEGINNING ON SUNDAY. HAVE FCST CONTINUED QUIET CONDS...BUT IF AN
APPROACHING WAVE OF LOW PRESSURE AND/OR FRONTAL SYSTEM ARE
STRONGER THAN FCST...HAZARDOUS OCEAN SEAS COULD DEVELOP IF
CORRESPONDING S-SW FLOW IS STRONGER THAN FCST.

&&

.HYDROLOGY...
THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE
WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON
WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY
STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL
COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE
AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN
THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT
IN THE HAZARDOUS WEATHER OUTLOOK.

LOW PRESSURE PASSING JUST OFF TO THE SE SUNDAY NIGHT INTO MON
MORNING...FOLLOWED BY A COLD FRONTAL PASSAGE LATER MON...HAVE SOME
POTENTIAL TO PRODUCE HEAVY RAIN...AS PRECIP EFFICIENCY INCREASES
TO OVER 1.5 INCHES. THIS WILL DEPEND FIRST ON THE LOW TRACK...THEN
ON POTENTIAL FOR TRAINING OF CELLS AHEAD OF THE COLD FRONT...AS
WELL AS OTHER MESOSCALE/THERMODYNAMIC FACTORS. GIVEN THESE
UNCERTAINTIES IT IS TOO EARLY TO OUTLOOK THIS IN THE HWO.

&&

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

&&

$$
SYNOPSIS...GOODMAN/MPS
NEAR TERM...MPS
SHORT TERM...MPS
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/MPS
HYDROLOGY...GOODMAN/MPS