Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 051747
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
147 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 AND FRIDAY NIGHT...THEN
WEAKEN NEARBY ON SATURDAY. A COLD FRONT WILL APPROACH FROM THE
WEST SATURDAY NIGHT...THEN MOVE ACROSS ON SUNDAY. HIGH PRESSURE
WILL BUILD IN EARLY NEXT WEEK. A WARM FRONTAL BOUNDARY MAY
APPROACH MID WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST HIGH-RES GUIDANCE INDICATES POTENTIAL FOR BREAKS IN THE
CLOUDS THIS AFTERNOON...AS MOIST H-9 LAYER DRIES OUT SOMEWHAT IN
BETWEEN A MID LEVEL SHORTWAVE PASSING TO THE WEST AND LOW PRESSURE
PASSES TO THE EAST. AS A RESULT BUMPED UP HIGH TEMPS PER GFS LAMP
FCST...WITH MID/UPPER 50S FOR MOST OF THE AREA...BUT STILL LOWER
50S FOR ERN CT/LONG ISLAND CLOSER TO THE OFFSHORE LOW TRACK AND
WHERE RADAR IS NOW SHOWING DRIZZLE DRIFTING IN FROM OFF THE OCEAN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WENT MAINLY DRY THIS EVENING AS MID LEVEL 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 CHANCE ELSEWHERE
EXCEPT SE CT AND FAR ERN LONG ISLAND...AS FORCING WITH UPPER LOW
MOVES IN 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.

THIS GENERAL SETUP CONTINUES ON FRIDAY...WITH H5 COLD POOL ALSO
MOVING ACROSS...AND SHOWALTER INDICES FALLING TO -2 TO +2. AS A
RESULT...LIKELY/CAT POP FOR RAIN WITH SLIGHT CHANCE FOR ELEVATED
THUNDER FRI AFTERNOON.

LOWS TONIGHT SHOULD BE NEAR TO SLIGHTLY BELOW AVG. HIGHS ON FRI
SHOULD BE IN THE 50S...10-15 DEG BELOW AVG.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE GENERAL H5 FLOW ACROSS
NORTH AMERICA THROUGH THE MIDDLE OF NEXT WEEK. AS USUAL...THERE
ARE SOME TIMING AND AMPLITUDE DIFFERENCES THAT START TO DEVELOP
OVER THE WEEKEND...ALTHOUGH THE GENERAL IDEA IS THAT THE
PERSISTENT BLOCKED UPPER PATTERN ACROSS THE CONUS WILL FINALLY
LOSE ITS GRIP NEXT WEEK.

CUTOFF LOW PRES NEAR THE MID ATLANTIC COAST FRI NIGHT WILL
GRADUALLY WEAKEN WHILE SLOWLY MOVING E THROUGH SAT NIGHT.
MEANWHILE...A SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA CUTS
OFF OVER ONTARIO WITH THE TWO SYSTEMS CONSOLIDATING INTO A BROAD
VORTEX OVER SE CANADA. THIS SYSTEM WILL GRADUALLY LIFT NE INTO THE
MARITIMES EARLY NEXT WEEK AS RIDGING OVER THE UPPER MIDWEST
FLATTENS WITH A SW UPPER FLOW DEVELOPING BY THE MIDDLE OF NEXT
WEEK.

AT THE SFC...WEAK SFC LOW PRES NEAR THE DELAWARE/NJ COAST
GRADUALLY WEAKENS S OF THE AREA THROUGH THE DAY SAT. WIDESPREAD
RAIN WILL GRADUALLY DRY OUT ACROSS THE AREA WITH DRY WEATHER
RETURNING BY SAT NIGHT. THE STRENGTH AND EXACT TRACK OF THIS LOW
STILL REMAIN IN QUESTION WHICH WILL IMPACT WIND STRENGTH/DIRECTION
AND ULTIMATELY ANY CONTINUED COASTAL FLOOD IMPACTS ON SAT. SEE
COASTAL FLOOD SECTION BELOW FOR MORE INFORMATION.

A COLD FRONT APPROACHES FROM THE WEST SAT NIGHT AND TRACKS THROUGH
ON SUN...BRINGING ANOTHER ROUND OF SHOWERS TO THE AREA. THERE ARE
TIMING DISCREPANCIES WITH THIS...WITH THE EC BEING SLIGHTLY FASTER
THAN THE GFS. THE BIGGER ISSUE THAT NEEDS TO BE RESOLVED IS THAT
THE GFS IS INDICATING MAINLY POST-FRONTAL PRECIPITATION AND
REALLY WRAPS THE SYSTEM UP ONCE IT PUSHES THROUGH RESULTING TO A
MUCH STRONGER PRESSURE PATTERN ACROSS THE AREA. RIDGING THEN
RETURNS THROUGH EARLY NEXT WEEK WITH TEMPERATURES GRADUALLY
RETURNING TO NEAR TO ABOVE NORMAL LEVELS.

A WARM FRONT APPROACHING FOR THE MIDDLE OF THE WEAK HAS THE
POTENTIAL TO STALL OVER OR NEAR THE AREA WITH WAVES OF LOW PRES
TRACKING ALONG IT. THERE IS HIGH BUST POTENTIAL IN THE TEMP
FORECAST ON WED DUE TO THIS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
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.

FROM NYC METRO WEST...MVFR TO VFR CEILINGS ARE EXPECTED THIS
AFTERNOON INTO THIS EVENING (3-4 KFT). GENERALLY MVFR EASTERN
TERMINALS ON LONG ISLAND AND SRN CT (2-3 KFT).

THEN...CEILINGS DETERIORATE LATE THIS EVENING AND
OVERNIGHT...MAINLY AFTER MIDNIGHT. MVFR TO IFR EXPECTED...AND
THESE IFR CONDITIONS CONTINUE FRIDAY MORNING IN DEVELOPING RAIN.

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

WINDS REMAIN NORTHEAST THIS AFTERNOON/EARLY EVENING. SPEEDS GENERALLY
10 TO 15 KT WITH OCCASIONAL GUSTS TO AROUND 20 KT.

GUSTS SHOULD BECOME LESS FREQUENT AFTER SUNSET...WITH WINDS
NORTH/NORTHEAST.

WINDS SHOULD INCREASE SLIGHTLY FRIDAY MORNING AS THEY VEER TO THE
EAST/NORTHEAST.

     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 FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. QUESTION WITH VFR OR MVFR CIGS REMAINS
RESULTING IN A LOWER TO MODERATE CONFIDENCE.

KLGA FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. QUESTION WITH VFR OR MVFR CIGS RESULTING IN A
LOWER TO MODERATE CONFIDENCE.

KEWR FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. QUESTION WITH VFR OR MVFR CIGS RESULTING IN A
LOWER TO MODERATE CONFIDENCE.

KTEB FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. MAINLY VFR CIGS ARE EXPECTED.

KHPN FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. MAINLY VFR CIGS ARE EXPECTED.

KISP FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS
AFTERNOON/EVENING. GENERALLY EXPECT MVFR CEILINGS ALTHOUGH VFR
CEILINGS ARE POSSIBLE LATE THIS AFTERNOON.

.OUTLOOK FOR 18Z FRI THROUGH TUE...
.FRIDAY AFTERNOON-FRIDAY NIGHT...PERIODS OF RAIN/FOG/LOW CLOUDS WITH
MVFR OR LOWER CONDITIONS. NE WINDS G15-20 KT FRIDAY.
.SATURDAY-SATURDAY NIGHT...SUB VFR POSSIBLE IN SHOWERS.
.SUNDAY AFTERNOON/NIGHT...COLD FRONTAL PASSAGE SHOULD FINALLY
BRING AN END TO DISMAL CONDITIONS...WITH CONDITIONS IMPROVING TO
VFR AND NW WINDS G20KT.
.MON...VFR. W WINDS G25KT POSSIBLE.
.TUE...MAINLY VFR ALTHOUGH SUB VFR IN RAIN IS POSSIBLE.

&&

.MARINE...
SCA REMAINS IN EFFECT THROUGH FRI NIGHT FOR THE OCEAN...AND
THROUGH THIS AFTERNOON FOR ERN LONG ISLAND SOUND...BUT HAS BEEN
DROPPED ELSEWHERE. A TIGHTENING PRESSURE GRADIENT AND WELL MIXED
BOUNDARY LAYER WILL PRODUCE GUSTS 25-30 KT ON THE OCEAN AND ERN
SOUND THIS AFTERNOON...BUT OBS SHOW BLYR MIXING TO BE NOT QUITE
AS EFFICIENT ELSEWHERE...SO GUSTS SHOULD REMAIN MOSTLY UNDER
25 KT ON THE WRN SOUND/HARBOR/BAYS. CURRENT FORECAST KEEPS
MARGINAL 5-FT SEAS ON THE OCEAN IN THE FORM OF SE-S SWELL THROUGH
SAT...BUT THIS REMAINS UNCERTAIN.

S FLOW INCREASES SAT NIGHT AHEAD OF AN APPROACHING COLD FRONT...
WITH POTENTIAL FOR SCA CONDITIONS ON ALL WATERS BEHIND THE FRONT
ON SUNDAY...BEFORE SUBSIDING SUN EVE. SEAS UP TO 5 FT MAY LINGER
ON THE EASTERN OCEAN WATERS INTO MON.

&&

.HYDROLOGY...
BASIN AVG RAINFALL OF 1/4 TO 1/2 INCH OF RAIN EXPECTED FRI INTO
SAT MORNING FOR SE CT AND ERN LONG ISLAND...AND 1/2 TO 2/3 INCH
FARTHER WEST FROM LATE TONIGHT INTO SAT MORNING. LOCALLY HIGHER
AMOUNTS POSSIBLE IN ANY HEAVIER SHOWERS OR TSTMS. PONDING OF
WATER IS POSSIBLE IN AREAS RECEIVING LOCALLY HEAVY RAINFALL.

RAINFALL UP TO 1/4 INCH IS POSSIBLE SATURDAY NIGHT INTO SUNDAY
WITH A COLD FRONTAL PASSAGE. NO HYDROLOGIC ISSUES ARE EXPECTED.

&&

.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.

WATER LEVELS MAY BRIEFLY TOUCH MINOR COASTAL FLOOD LEVELS IN A
FEW SOUTH SHORE BAY LOCALES ON SOUTHWESTERN LONG ISLAND WITH THE
FRIDAY MORNING HIGH TIDE CYCLE.

FOR TONIGHT...ASTRONOMICAL TIDE HEIGHTS WILL BE 1/4-1/2 FT HIGHER
THAN THOSE OF LAST NIGHT...WHILE TIDAL DEPARTURES SHOULD BE NEAR
TO MAYBE A 1/4 FT HIGHER THAN LAST NIGHT. 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
SOME SPOTS ALONG THE BACK BAYS OF SRN NASSAU AND SW SUFFOLK TO HIT
MODERATE FLOOD THRESHOLDS THIS EVENING...BUT THE PROBABILITY
REMAINS TOO LOW FOR A WARNING AT THIS TIME. MINOR FLOOD LEVELS
WILL BE APPROACHED AND POSSIBLY LOCALLY TOUCHED ACROSS THE
REMAINING EASTERN COASTAL AREAS.

FOR FRI NIGHT...WIDESPREAD MINOR COASTAL FLOODING EXPECTED ONCE
AGAIN AS ASTRONOMICAL TIDES PEAK AND SURGE LIKELY REMAINS STEADY.
MODERATE COASTAL FLOODING COULD OCCUR ALONG THE SOUTH SHORE BAYS
OF WESTERN LONG ISLAND AND QUEENS....WITH ONLY 1 TO 1 1/4 FT
SURGE NEEDED IN SPOTS.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
     TONIGHT FOR CTZ009-010.
NY...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
     TONIGHT FOR NYZ071-078-177.
     COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
     NYZ074-075-080-178-179.
NJ...COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
     NJZ006-106-108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ350-353-
     355.

&&

$$
SYNOPSIS...GOODMAN/24/MALOIT
NEAR TERM...GOODMAN/MALOIT
SHORT TERM...GOODMAN/MALOIT
LONG TERM...24
AVIATION...PW
MARINE...GOODMAN/24/MALOIT
HYDROLOGY...GOODMAN/24/MALOIT
TIDES/COASTAL FLOODING...



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