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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 211445
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1045 AM EDT TUE MAY 21 2013

.SYNOPSIS...
A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE AREA TODAY THROUGH WEDNESDAY.
A COLD FRONT WILL PASS THROUGH THE AREA THURSDAY EVENING INTO
THURSDAY NIGHT. HIGH PRESSURE WILL RETURN FOR THE WEEKEND AND EARLY
NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
FOG/STRATUS HAS BURNED OFF IN ALL AREAS EXPECT THE SOUTH SHORE OF
LONG ISLAND WHERE ADVECTION FOG IS EXPECTED TO PERSIST THROUGH
THE OVERNIGHT. BASED ON WEB CAMS SHOWING NEAR ZERO VISIBILITY...WE
HAVE ISSUED A DENSE FOG ADVISORY FOR SOUTHERN NASSAU AND SUFFOLK
THROUGH 6 PM. THIS WILL LIKELY BE ADJUSTED THIS AFTERNOON AND THEN
EXTENDED THIS EVENING.

OTHERWISE...CLEAR SKIES EARLY ALLOW FOR FULL SUN HEATING.
THUS...TEMPS WELL INTO THE 80S EXCEPT FOR THOSE REGIONS ALONG THE
COAST.

THE HEATING RESULTS IN SIGNIFICANT INSTABILITY THIS AFTN. LATEST NWP
FORECAST SOUNDINGS INDICATE WELL OVER 2000 J/KG OF SFC BASED CAPE
WITH LI`S NEAR -8 C IN THE NORTHERN ZONES. SOME SREF SOUNDING ARE
OVER 3000 J/KG. THUS...FULLY EXPECT DEEP CONVECTION TO FIRE THIS
AFTERNOON AND SINK SOUTHWARD INTO THE FORECAST AREA. THIS IS IN
AGREEMENT WITH LATEST RUNS OF THE CAM`S - HRRR...SPC WRF AND NSSL
WRF.

WITH LIMITED SHEAR...SEVERE POTENTIAL IS LOW. THINKING THOUGH
THAT FLOODING COULD BE AN ISSUE. FFG IS OVER 2 INCHES IN ONE
HOUR...BUT SEE THE CAM`S PRODUCING THESE AMOUNTS. WITH THE WEAK
SHEAR AND PWAT`S NEAT 1.5 INCHES...WILL NEED TO WATCH THIS. MAY
HIGHLIGHT THIS IN THE HAZARDOUS WEATHER OUTLOOK WITH 1 PM UPDATE.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
-- Changed Discussion --
ANY LINGERING CONVECTION THIS EVENING DIMINISHES IN COVERAGE AS IS
SAGS SOUTH. MAIN ISSUE LATTER TONIGHT WILL BE THE DEVELOPMENT OF
FOG ONCE AGAIN AS SOUTHERLY WINDS PREVAIL AND THE AIRMASS REMAINS
QUITE MOIST.

LOWS WILL BE QUITE WARM...60S PER MOS.

FOR WEDNESDAY...RIDGE SLOWLY SHIFTS EAST AS UPSTREAM TROUGH
FINALLY MAKES EASTWARD PROGRESS. HOWEVER...ANOTHER WARM DAY IS ON
TAP. MORNING FOG AND STRATUS WILL GIVE WAY TO AT LEAST PARTIAL
SUNSHINE. ONCE AGAIN...CONVECTION SHOULD BE SCATTERED AT BEST WITH
WEAK TO MARGINAL INSTABILITY IN PLACE.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM NEAR THE CANADIAN
BORDER WEDNESDAY NIGHT INTO THURSDAY MORNING. THE COLD FRONT IS
EXPECTED TO MOVE ACROSS THE AREA THURSDAY EVENING TRIGGERING SCT
SHOWERS AND THUNDERSTORMS. THIS FRONT WILL THEN MOVE OFFSHORE BY
FRIDAY MORNING WITH A WAVE OF LOW PRESSURE MOVING NORTHEAST ALONG
IT...KEEPING SHOWERS ACROSS THE AREA THROUGH FRIDAY AFTERNOON.

EXPECT HIGHS ON THURSDAY TO BE IN THE MID TO UPPER 70S WITH LOWS
THURSDAY NIGHT IN UPPER 50S TO AROUND 60.

FRIDAY NIGHT THROUGH MONDAY...AN AREA OF HIGH PRESSURE WILL
DROP SOUTHEAST FROM CENTRAL CANADA INTO THE CENTRAL US AND BUILD
EASTWARD THROUGH MEMORIAL DAY. HIGHS SATURDAY THROUGH MEMORIAL DAY
ARE EXPECTED TO BE IN THE UPPER 60S TO AROUND 70 WITH LOWS IN THE
MID 40S TO LOWER 50S.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
A FRONTAL BOUNDARY DRAPED FROM W TO E THROUGH NEW ENGLAND WILL
REMAIN NEARLY STATIONARY TODAY. IT MAY SINK SLIGHTLY S BUT IS
EXPECTED TO REMAIN N OF THE TERMINALS.

STRATUS/FOG OVER THE TERMINALS WILL GRADUALLY LIFT AND BURN OFF
THIS MORNING. CONDS START OUT LIFR/IFR AND SHOULD LIFT BACK TO
VFR BETWEEN 14Z AND 16Z. VFR THEN EXPECTED INTO THE EVE BEFORE
FOG/STRATUS RETURNS.

MEANWHILE...A COLD FRONT WILL SLOWLY SAG DOWN FROM THE NORTH WITH
A SFC TROUGH DEVELOPING IN THE LEE OF THE APPALACHIANS. CONVECTION
WILL LIKELY FIRE NEAR BOTH OF THESE BOUNDARIES...BUT THERE`S SOME
QUESTION HOW FAR S AND E TSTMS WILL MAKE IT BEFORE THE FIZZLE DUE
TO THE LOSS OF DAYTIME HEATING. ONLY HAVE TEMPO AT KSWF LATE THIS
AFTN/EARLY EVE FOR THIS.

     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: AMENDMENTS POSSIBLE FOR IMPROVING CONDS THIS
MORNING. LOW CHC OF EVENING CONVECTION.

KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR IMPROVING CONDS THIS
MORNING. LOW CHC OF EVENING CONVECTION.

KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR IMPROVING CONDS THIS
MORNING. LOW CHC OF EVENING CONVECTION.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR IMPROVING CONDS THIS
MORNING. LOW CHC OF EVENING CONVECTION.

KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR IMPROVING CONDS THIS
MORNING. LOW CHC OF EVENING CONVECTION.

KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR IMPROVING CONDS
THIS MORNING.

.OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
.WED...IFR IN FOG AND STRATUS IMPROVING TO VFR IN THE MORNING. SCT
SHOWERS/TSTMS IN THE AFTN/EVE.
.WED NIGHT-FRI...SCT SHOWERS/TSTMS. AT NIGHT...IFR POSSIBLE WITH
STRATUS/FOG.
.SAT...VFR.

&&

.MARINE...
-- Changed Discussion --
DENSE FOG ACROSS THE WATERS NEAR SHORE OCEAN AND GREAT SOUTH BAY.
THIS ADVECTION FOG IS EXPECTED TO PERSIST INTO WEDNESDAY.

SOUTH WINDS THIS AFTERNOON WITH SUB SCA CONDITIONS.

CONTINUED SOUTH TO SOUTHWEST FLOW IS FORECAST FOR TONIGHT AND
WEDNESDAY AS A FRONTAL BOUNDARY REMAINS TO THE NORTH. SEAS WILL
REMAIN BELOW 5 FT OVER THE OCEAN WATERS...1 FT OR LESS ELSEWHERE
TODAY AND LIKELY TONIGHT.

LATEST WAVE WATCH III GUIDANCE FOR THE OCEAN WATERS SUGGEST 5 TO
6 FT SEAS BY WEDNESDAY DUE TO PERSISTENT SOUTH FLOW AND POSSIBLE
SOUTHERLY SWELL. HOWEVER...WAVE WATCH HAS BEEN OVER FORECASTING
SEAS BY A FOOT OR TWO...SO CONFIDENCE IN THIS HAPPENING IS NOT
HIGH AT THIS TIME.

SEAS EXPECTED TO BE ABOVE SCA LEVELS WEDNESDAY NIGHT...WITH 25 KT
WIND GUSTS POSSIBLE ON THE OCEAN WATERS BY WEDNESDAY EVENING. A COLD
FRONT WILL MOVE ACROSS THE AREA WATERS THURSDAY EVENING INTO
THURSDAY NIGHT...WITH HIGH PRESSURE BUILDING IN AT THE SURFACE ON
LATE ON FRIDAY. WINDS COULD BE BELOW SCA LEVELS BY FRIDAY
MORNING...WITH SEAS REMAINING ABOVE SCA CRITERIA THROUGH SATURDAY
MORNING.
-- End Changed Discussion --

&&

.HYDROLOGY...
-- Changed Discussion --
SCT TSTMS LATE IN THE DAY TODAY...MAINLY INLAND. POSSIBLE
LOCALIZED FLASH FLOODING WITH UP TO 3 INCHES.

SCT SHOWERS/TSTMS WED-THU WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
RAINFALL...WITH THE BEST CHANCES NORTH/WEST OF NYC. TOTAL BASIN
AVG QPF FOR WED-THU COULD BE 1/4 TO 1/2 INCH...WITH LOCALLY HIGHER
AMTS IN TSTMS.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT THURSDAY FOR ANZ345-350-353-
     355.
-- End Changed Discussion --

&&

$$
SYNOPSIS...
NEAR TERM...TONGUE
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...