Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 060042
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
842 PM EDT THU MAY 5 2016

.SYNOPSIS...
LOW PRESSURE WELL OFF THE MID ATLANTIC COAST WILL MOVE TOWARD NOVA
SCOTIA THROUGH TONIGHT. ANOTHER OFFSHORE LOW WILL MOVE SLOWLY NORTH
UP THE MID ATLANTIC COAST FRIDAY INTO SATURDAY. THE LOW WILL BE
USHERED OUT TO SEA BY A COLD FRONT ON SUNDAY. FAIR WEATHER ON
MONDAY WILL BE FOLLOWED BY INCREASING CLOUDS AND SOME RAIN
CHANCES THROUGH THE MIDDLE OF NEXT WEEK AS A WARM FRONT DEVELOPS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SLIGHT ADJUSTMENTS WERE MADE WITH TEMPERATURES...DEWPOINTS...AND
CLOUD COVERAGE AS WELL AS THE PATCHY DRIZZLE. THE FORECAST
OVERALL IS ON TRACK.

EXPECT OVERCAST SKIES TONIGHT...WITH SPOTTY DRIZZLE ACROSS MUCH
OF LONG ISLAND AND SOUTHERN CT. OTHERWISE...MAINLY DRY THIS
EVENING AS MID LEVELS ALSO DRY OUT IN BETWEEN ONE DEPARTING LOW
AND ANOTHER APPROACHING LOW...THEN LIKELY POP FOR RAIN LATE
TONIGHT FOR NYC METRO/NE NJ AND NEARBY AREAS...AND CHANCE FARTHER
NORTH/EAST... AS MID LEVEL FORCING WITH UPPER LOW APPROACHES FROM
THE SOUTH...AND AS A WEAK OFFSHORE LOW DEVELOPING OFF HATTERAS
THIS EVENING PIVOTS BACK IN CLOSER TO THE DELMARVA COAST IN
RESPONSE TO THIS FORCING.

LOWS IN THE 40S.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
RAIN CONTINUES ON FRI AS UPPER LOW AND MID LEVEL FORCING HEAD
RIGHT UP INTO THE AREA...AND AS SFC LOW MOVES SLOWLY UP THE COAST.
ENE FLOW NORTH OF THE SFC LOW WILL BE GUSTY ESPECIALLY IN THE
MORNING AND EARLY AFTERNOON...REACHING 35 MPH AT TIMES. WITH H5
COLD POOL ALSO MOVING ACROSS...AND SHOWALTER INDICES FALLING TO
AROUND ZERO...STILL HAVE SLIGHT CHANCE FOR ELEVATED THUNDER
THROUGH THE DAY FRI INTO FRI EVENING. THE SFC LOW SHOULD
RETROGRADE INTO NJ/PA FRI NIGHT...WITH PRECIP BECOMING
LIGHT/SPOTTY ONCE AGAIN.

HIGHS ON FRI SHOULD BE IN THE 50S...STILL 10-15 DEG BELOW AVG.
LOWS FRI NIGHT IN THE UPPER 40S/LOWER 50S.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
GENERAL PATTERN IS FOR A WEAKENING UPR LOW TO LINGER ON SAT...THEN
EXIT ON SUN DUE TO COLD FROPA. A BROAD AREA OF HIGH PRES WEDGES
IN FOR MON...THEN A WARM FRONT WILL DEVELOP INVOF THE CWA TUE AND
WED...PERHAPS SINKING SWD ON THU AS A CDFNT.

THERE IS SOME MODEL DISAGREEMENT RIGHT OFF THE BAT SAT WRT THE H5
LOW. THE NAM IS 100-200 MILES FURTHER N THAN THE ECMWF...GFS AND GFS
ENSEMBLES. ALTHOUGH THE GFS AND ECMWF ARE PREFERRED THIS FAR
OUT...SOME CONSIDERATION GIVEN TO THE NAM GIVEN POSSIBLE CONVECTIVE
INPUTS NEAR THE UPR LVL FEATURE. AS A RESULT...KEPT CHC POPS IN THE
FCST AND WENT BLW THE WARMER GFS BASED STATISTICAL TEMPS.

THE UPR LOW CONTINUES TO WEAKEN SAT NGT WITH MOISTURE DWINDLING.
ONLY SLGT CHC POPS AS A RESULT FOR MOST OF THE NGT. THE CDFNT THEN
APPROACHES SUN MRNG...AND THE MODELS CONTINUE TO PRODUCE
MEASURABLE PCPN PARTICULARLY NRN ZONES. BASED ON THE CONSISTENCY
HAVE INTRODUCED LIKELY POPS FOR APPROXIMATELY THE NRN 2/3 OF THE
CWA. CURRENT TIMING STILL HAS THE PCPN ENDING BY 18Z...SO A DRY LATE
AFTN IS EXPECTED ATTM.

DRY WX ON MON WITH MOSTLY SUNNY SKIES VIA SUBSIDENCE. DESPITE THE
COOLER AIR MASS...HIGH TEMPS WARMER THAN SUN WITH DEEPER MIXING.

MODEL UNCERTAINTY CREEPS IN AGAIN TUE-THU. WENT WITH THE GENERAL
IDEA OF WARM FRONT BECOMING STATIONARY IN THE REGION...RESULTING IN
AT LEAST BKN-OVC SKIES. POPS CLOSE TO THE PREV OFFICIAL AROUND 30
PERCENT TUE AND WED. THERE IS THE SUGGESTION THAT THE HIGH MAY
REMAIN FIRM AND KEEP THE CWA MAINLY DRY...AT LEAST THRU WED.
HOWEVER...PREV RUNS AND THE SPECTRUM OF DATA ALSO HINTS AT PERIODS
OF RAIN FOR TUE-THU.

TEMPS CLOSE TO THE SUPERBLEND THRU THE LONG TERM...EXCEPT A BLEND OF
THE MET/MAV WAS USED SAT TO REFLECT EXPECTED WARMER READINGS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
ANOTHER AREA OF LOW PRESSURE FORMING OFF THE MID ATLANTIC COAST
THIS EVENING WILL IMPACT THE AREA LATE TONIGHT THROUGH FRI.

EXPECT MAINLY MVFR CIGS FOR MUCH OF THE NIGHT WITH OCCASIONAL
VFR CIGS IN AND AROUND THE NYC TERMINALS. CONDITIONS THEN
DETERIORATE TOWARD DAYBREAK WITH WIDESPREAD IFR CONDITIONS
FORECAST TO DEVELOP IN A STEADY RAIN. THERE IS SOME UNCERTAINTY
WITH THE TIMING OF THE CATEGORY CHANGES.

VFR VSBYS FALL TO MVFR AND POSSIBLY IFR LATE TONIGHT AND FRIDAY
MORNING.

WINDS REMAIN NORTHEAST WITH OCCASIONAL GUSTS TO 20 KT AT THE
COASTAL TERMINALS THIS EVENING...THEN REDEVELOP FRI MORNING.
WINDS WILL GRADUALLY BACK THE EAST BY FRI AFTERNOON.


     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

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

KJFK FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

KHPN FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING OF CATEGORY
CHANGES FRI MORNING.

.OUTLOOK FOR 00Z SAT THROUGH TUE...
.FRIDAY NIGHT...PERIODS OF LIGHT RAIN/FOG/LOW CLOUDS WITH IFR OR
LOWER CONDITIONS.
.SATURDAY-SATURDAY NIGHT...SUB VFR POSSIBLE WITH A CHANCE OF SHOWERS.
.SUNDAY AFTERNOON/NIGHT...COLD FRONTAL PASSAGE IN THE MORNING WITH
VFR CONDITIONS AND NW WINDS G20KT IN THE AFTERNOON.
.MON...VFR.
.TUE...MAINLY VFR ALTHOUGH SUB VFR IN RAIN IS POSSIBLE.

&&

.MARINE...
SCA CONDS CONTINUE ON THE OCEAN...MAINLY EAST OF FIRE ISLAND
INLET AND ERN LI SOUND. COULD BE A FEW GUSTS UP TO 35 KT ON THE
FAR ERN OCEAN WATERS INTO THIS EVENING. REST OF WATERS ARE BELOW
SCA TONIGHT.

AS SFC LOW PRESSURE APPROACHES FROM THE SOUTH ON FRI...ENE WINDS
WILL INCREASE...WITH AT LEAST SCA CONDS EXPECTED ON ALL WATERS.
WINDS ON THE OCEAN COULD GUST AS HIGH AS 35-40 KT...ESPECIALLY IF
STRONGER 12Z GFS SOLN PREVAILS. DUE TO UNCERTAINTY ON THE
TIMING/DURATION/STRENGTH OF PEAK WINDS ON THE OCEAN...ISSUED A
GALE WATCH INSTEAD OF A GALE WARNING.

SCA SEAS ON THE OCEAN FRI NIGHT INTO SAT...DECREASING SAT NGT BUT
MAY LINGER AROUND 5 FT INTO MON. IMPROVEMENT MON AND TUE WITH HIGH
PRES INFLUENCING THE WATERS. WRT WINDS...SPEEDS GENERALLY BLW SCA
LVLS SAT-TUE. EXCEPTION MAY BE SUN AFTN...WHERE WNW FLOW COULD
APPROACH CRITERIA...ESPECIALLY NEARSHORE.

&&

.HYDROLOGY...
LATE TONIGHT INTO SAT MORNING...BASIN AVG RAINFALL OF 1/2 TO 3/4
INCH EXPECTED FROM NYC METRO NORTH/WEST...AND 1/4 TO 1/2 INCH
FARTHER EAST. LOCALLY HIGHER AMOUNTS ARE POSSIBLE IN ANY HEAVIER
SHOWERS OR TSTMS. PONDING OF WATER IS POSSIBLE IN AREAS RECEIVING
LOCALLY HEAVY RAINFALL.

A FEW TENTHS OF AN INCH OF RAIN AT MOST ARE EXPECTED OVER THE
WEEKEND. DRY WX ON MON.

&&

.TIDES/COASTAL FLOODING...
THE HIGHEST SPRING TIDE OF THE YEAR IS APPROACHING WITH THE NEW
MOON ON FRIDAY. THE THREAT FOR MINOR TO LOCALLY MODERATE COASTAL
FLOODING WILL INCREASE DURING THE EVENING HIGH TIDES THROUGH
FRIDAY...AND LIKELY CONTINUE INTO THIS WEEKEND.

FOR TONIGHT...ASTRONOMICAL TIDE HEIGHTS WILL BE 1/4-1/2 FT HIGHER
THAN THOSE OF LAST NIGHT...WHILE TIDAL DEPARTURES SHOULD BE 1 TO 1
1/2 FT. THIS SHOULD RESULT IN MORE WIDESPREAD MINOR COASTAL
FLOODING ALONG THE SOUTH SHORE BAYS OF WESTERN LONG ISLAND/NYC AND
WESTERN LONG ISLAND SOUND AND NY HARBOR...WHERE AN ADVISORY HAS
BEEN ISSUED. THERE IS POTENTIAL FOR SPOTS ALONG THE BACK BAYS OF
SRN NASSAU AND SW SUFFOLK TO TOUCH MODERATE FLOOD THRESHOLDS THIS
EVENING. MINOR FLOOD LEVELS WILL BE APPROACHED AND POSSIBLY
LOCALLY TOUCHED ACROSS THE REMAINING EASTERN COASTAL AREAS.

FOR FRI NIGHT...ASTRONOMICAL TIDES PEAK. SURGE LIKELY REMAINS AT
LEAST STEADY...AND COULD BE A LITTLE HIGHER IF STRONGER EASTERLY
WINDS PER 12Z GFS MATERIALIZE. WIDESPREAD MODERATE COASTAL
FLOODING MAY BE POSSIBLE FOR LOWER NEW YORK BAY/RARITAN
BAY/JAMAICA BAY AND THE SOUTH SHORE BAYS OF NASSAU...WITH ONLY 1
TO 1 1/4 FT SURGE NEEDED..AND A COASTAL FLOOD WATCH HAS BEEN
ISSUED. WIDESPREAD MINOR COASTAL FLOODING EXPECTED MOST ELSEWHERE.

FOR SAT...WIDESPREAD MINOR COASTAL FLOODING STILL POSSIBLE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR CTZ009-
     010.
NY...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ071-
     078-177.
     COASTAL FLOOD WATCH FRIDAY EVENING FOR NYZ074-075-178-179.
     COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NYZ074-
     075-080-178-179.
NJ...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NJZ006-
     106-108.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 6 PM EDT FRIDAY FOR ANZ330-
     335-338-340-345.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ330.
     GALE WATCH FROM 7 AM EDT FRIDAY THROUGH FRIDAY AFTERNOON FOR
     ANZ350-353-355.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR ANZ350-353-355.

&&

$$

SYNOPSIS...JMC/GOODMAN
NEAR TERM...GOODMAN/JM
SHORT TERM...GOODMAN
LONG TERM...JMC
AVIATION...DW
MARINE...JMC/GOODMAN/JM
HYDROLOGY...JMC/GOODMAN
TIDES/COASTAL FLOODING...BG



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