Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 301442
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1042 AM EDT TUE JUN 30 2015

.SYNOPSIS...
HIGH PRESSURE SLIDES EAST TODAY...WITH A WEAK FRONTAL SYSTEM
APPROACHING TONIGHT AND MOVING THROUGH ON WEDNESDAY. A COLD FRONT
WILL SLOWLY MOVE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY
WITH CANADIAN HIGH PRESSURE BUILDING INTO THE NORTHEAST IN ITS
WAKE. WAVES OF LOW PRESSURE WILL TRAVERSE THE STATIONARY BOUNDARY
TO OUR SOUTH THROUGH THE WEEKEND. A WARM FRONT WILL LIFT THROUGH
THE REGION ON MONDAY WITH A COLD FRONT APPROACHING MONDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST REMAINS TRACK. SHOWERS AND CONVECTION EXPECTED TO REMAIN
MAINLY OVER ORANGE COUNTY THIS AFTERNOON. THUS INCREASED POPS
THERE AND LOWERED THEM TO NONE FOR EAST OF THE HUDSON. OTHER
CHANGE WAS TO THE SKY COVER - WHICH IS CLEAR EAST. SOME CLOUDS
SPILL INTO LONG ISLAND AND CT...BUT STILL A MOSTLY SUNNY DAY
THERE. NYC IS EXPECT TO BECOME CLOUDY.

LATEST HURR AND SPC CAMS SUPPORT THE FCST FOR CONVECTION REMAINING
WEST OF THE HUDSON THROUGH THIS AFTERNOON.

OTHERWISE...UPPER TROUGH SHARPENS INTO THE OHIO VALLEY
TODAY...WITH WESTERN ATLANTIC RIDGING REMAINING FIRM. AT THE
SURFACE...A RESULTANT WEAK LOW PRESSURE SYSTEM DRIFTS E ACROSS THE
GREAT LAKES...WITH ITS WARM FRONT MAKING SLOW PROGRESS THROUGH
CENTRAL PA AND MID ATLANTIC DURING THE DAY.

INCREASING HIGH AND MID CLOUD COVER ACROSS WESTERN PORTIONS OF THE
TRI-STATE THIS MORNING...GRADUALLY SPREADING EASTWARD THROUGH THE
AFTERNOON IN SW FLOW ALOFT. POTENTIAL FOR LATE DAY SHRA/TSRA
ACTIVITY DRIFTING NE FROM EASTERN PA...INTO AREAS WELL W AND NW
OF NYC.

CONSIDERABLE CLOUD COVER ACROSS NYC METRO AND POINTS N&W...AND
S/SE FLOW WILL KEEP TEMPS IN THE UPPER 70S/LOWER 80S ACROSS MUCH
OF THE REGION.

A MODERATE RIP CURRENT RISK EXISTS TODAY WITH ONSHORE FLOW AND
LINGERING 3 FT S SWELLS. THE RIP RISK MAY BE A MARGINAL HIGH RISK
ACROSS EASTERN LI BEACHES EARLY THIS MORNING WITH 4 FT S SWELLS
AND ONSHORE FLOW...BUT SHOULD DROP TO MODERATE AFTER DAYBREAK.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
UPPER TROUGH SLIDES SLOWLY EASTWARD TONIGHT AND THEN PIVOTS NE
THROUGH THE REGION ON WEDNESDAY. AT THE SURFACE...THE WARM FRONT
MAKES SLOW PROGRESS TOWARDS THE REGION TONIGHT...BUT LIKELY NOT
LIFTING NORTH TILL WEDNESDAY MORNING AHEAD OF APPROACHING COLD
FRONT. POSSIBILITY OF A WEAK TRIPLE PT WAVE TO DEVELOP AND MOVE
ACROSS THE REGION WEDNESDAY MORNING/EARLY AFT AS WELL.

FORCING AND INSTABILITY GRADUALLY INCREASE ACROSS W/SW PORTIONS OF
THE TRI-STATE OVERNIGHT AS WARM FRONT AND POTENTIAL DEVELOPING
TRIPLE PT WAVE APPROACH THE REGION. THIS SHOULD POSE AN INCREASING
POTENTIAL FOR SHOWERS AND SCT TSTMS FROM SW TO NE LATE TONIGHT INTO
WEDNESDAY MORNING. BEST COVERAGE OF SHOWERS AND TSTM LOOKS TO BE WED
MORNING INTO EARLY AFTERNOON AS SHORTWAVE TROUGH APPROACHES AND WARM
FRONT/WAVE LIFTS THROUGH.

IN WAKE OF WARM FRONT/TRIPLE POINT WAVE...BEST MOISTURE AXIS
APPEARS TO SLIDE EAST OF THE REGION. SO UNCERTAINTY FOR AFTERNOON
CONVECTION IN TERMS OF AMOUNT DESTABILIZATION BEFORE AFTERNOON
SHORTWAVE PASSAGE. SCATTERED CONVECTION POSSIBLE AHEAD OF COLD
FRONT NW & W OF NYC...OR ALONG ANY THERMAL OR LINGERING PRE-
FRONTAL TROUGH.

WITH DECENT SHEAR PROFILES AND LLJ...CANT RULE
OUT AN ISOLATED STRONG TO SEVERE STORM WITH EVEN SOME WEAK ROTATION
ALONG WARM FRONT/DEVELOPING TRIPLE PT WAVE. POTENTIAL IS LOW
OVERALL...BUT SHOULD INCREASE THROUGH THE MORNING INTO EARLY
AFTERNOON WITH BUILDING INSTABILITY. CONDITIONAL POTENTIAL FOR A FEW
STRONG TO SEVERE STORMS IN THE EARLY TO MID AFTERNOON AS SHORTWAVE
IS COMING THROUGH...ALONG COLD FRONT AND ANY LINGERING BOUNDARY.

SETUP DOES NOT LOOK FAVORABLE FOR WIDESPREAD CONVECTION LATE IN THE
AFTERNOON INTO EVENING AS SHORTWAVE AXIS LOOKS TO BE PIVOTING EAST
OF THE REGION. COVERAGE MAY BE MORE ISOLATED ALONG THE LAGGING COLD
FRONT AS IT PASSES THROUGH...WITH A DIMINISHED SEVERE THREAT DUE TO
SUBSIDENCE AND A DRYING AIRMASS.

HIGHS NEAR SEASONABLE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
00Z DETERMINISTIC SOLNS...WITH THE EXCEPTION OF THE CMC...HAVE COME
INTO BETTER AGREEMENT WITH THE H5 PATTERN ACROSS NOAM THROUGH THE
WEEKEND. HOWEVER...ISSUES WITH TIMING AND AMPLITUDE OF THE NRN
STREAM FLOW BEGIN TO BECOME APPARENT ON SAT WITH LARGE DIFFERENCES
DEVELOPING BY EARLY NEXT WEEK...ESPECIALLY OUT WEST.

MEAN TROUGH OVER THE ERN US WILL REMAIN THROUGH THE END OF THE
WEEK...BEFORE A SPLIT FLOW DEVELOPS OVER THE WEEKEND. THE DEGREE OF
DOWNSTREAM AMPLIFICATION ACROSS ERN CANADA AND NERN PORTION OF THE
CONUS WILL DETERMINE IF AND WHEN THE NEXT CUTOFF LOW PRES SYSTEM
TRAVERSING THE CANADIAN PROVINCES WILL IMPACT THE LOCAL AREA NEXT
WEEK.

ANY CONVECTION AHEAD OF A COLD FRONT WED EVE IS EXPECTED TO WIND
DOWN FAIRLY QUICKLY DUE TO THE LACK OF SHORTWAVE ENERGY AND
ADDITIONAL UPPER LEVEL SUPPORT. COULD SEE A FEW STRAY TSTMS RIGHT
ALONG THE FRONT. NAM IS THE SLOWEST WITH THE FROPA WITH PARENT LOW
PRES SYSTEM CUTTING OFF ALOFT AND SFC LOW TRACKING DUE N THU NIGHT.
IT IS ALSO SLIGHTLY STRONGER THAN THE REMAINING GUIDANCE. AT ANY
RATE...ALL SOLNS INDICATE THE SYSTEM CUTTING OFF AND GRADUALLY
LIFTING N/NE THU/THU NIGHT LEADING TO A SLOW FRONTAL PROGRESSION
ACROSS THE AREA. AS THE UPPER LOW DEPARTS...SHORTWAVE ENERGY
TRACKING THROUGH NEW ENGLAND COULD TRIGGER AN ISOLD SHOWER/TSTM
ACROSS THE INTERIOR THU. ADDITIONALLY...SEVERAL PIECES OF SHORTWAVE
ENERGY TRACKING AROUND THE BASE OF THE MEAN TROUGH WILL RESULT IN
WAVES OF LOW PRES TRACKING ALONG THE BOUNDARY.

TRENDS FROM THE 12Z GUIDANCE HAVE SHIFTED THE FRONTAL BOUNDARY
FURTHER S WITH CANADIAN HIGH PRES BUILDING INTO THE NE PROVIDING DRY
AND SLIGHTLY COOLER WEATHER FOR FRI. SAT MAY END UP BEING DRY IF THE
HIGH HANGS ON AND KEEPS A FRONTAL WAVE SUPPRESSED TO THE S. DRY
WEATHER IS THEN EXPECTED TO CONTINUE WITH RISING HEIGHTS AND WARM
ADVECTION SUN INTO MON AS A WARM FRONT LIFTS THROUGH.

TEMPS ARE EXPECTED TO BE NEAR SEASONABLE LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE DRIFTS OVER THE ATLANTIC THIS AFTERNOON. A WARM FRONT
APPROACHES FROM THE SOUTH TONIGHT AND LIFTS THROUGH WEDNESDAY
MORNING.

VFR THRU THE AFTERNOON AND EVENING. ANY SHOWERS LIKELY REMAIN WEST
OF TERMINALS...ALTHOUGH KSWF COULD SEE A FEW PASSING SHOWERS.

BETTER CHANCE FOR SHOWERS MAINLY AFTER 8Z...BUT THERE COULD ALSO BE
SOME STRATUS DURING THE SAME PERIOD INVOF THE FRONT. MVFR LIKELY FOR
THE FIRST HALF OF WED.

SOUTH WINDS 5 TO 10 KTS WILL INCREASE FROM THE S/SE DURING THE
AFTERNOON. WINDS LIGHTEN AND TURN FURTHER TO THE ESE TONIGHT.

...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: SPEEDS INCREASE TO AROUND 15 KTS BY 17-19Z.

KLGA FCSTER COMMENTS: OCCASIONAL TO FREQUENT GUSTS 15 TO 20 KTS
EXPECTED THIS AFTERNOON.

KEWR FCSTER COMMENTS: DEVELOPING AFTERNOON SHOWERS ARE EXPECTED TO
REMAIN TO THE WEST.

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

KTEB FCSTER COMMENTS: DEVELOPING AFTERNOON SHOWERS ARE EXPECTED TO
REMAIN TO THE WEST.

KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

.OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
.WEDNESDAY-SATURDAY...MVFR OR LOWER POSSIBLE AT TIMES THROUGH THE
PERIOD IN SHRA AND POSSIBLE TSRA.

&&

.MARINE...
SUB SCA CONDITIONS TODAY WITH WEAK HIGH PRESSURE. NEAR SHORE WIND
IN THE NY BIGHT AND HARBOR WILL INCREASE THIS AFTERNOON WITH GUSTS
TO THE LOWER 20S.

OCEAN SEAS WILL GRADUALLY BUILD ON WED AHEAD OF A COLD FRONT.
POTENTIAL FOR MARGINAL SCA SEAS BY WED EVE.

WINDS ARE EXPECTED TO REMAIN BLO SCA LEVELS THROUGH THE
PERIOD...ALTHOUGH IF THE STRONGER NAM SOLN ENDS UP VERIFYING THU
NIGHT INTO FRI...WINDS COULD GET CLOSE. OTHERWISE...A SLY SWELL MAY
BRING SEAS ON THE OCEAN ABOVE 5 FT WED NIGHT AND CONTINUE THROUGH
THU EVE WITH SUB- SCA CONDS THEREAFTER.

&&

.HYDROLOGY...
POTENTIAL FOR SCATTERED THUNDERSTORMS TO PRODUCE LOCALLY HEAVY
RAINFALL LATE TONIGHT INTO WEDNESDAY. THE FORECAST BASIN AVG OF
RAIN IS AROUND A HALF INCH BUT LOCALLY 1+ IS POSSIBLE.

MAIN THREAT WILL BE FOR MINOR URBAN FLOODING WITH ANY
CONVECTION...WITH A LOW THREAT OF FLASH FLOODING WITH ANY
TRAINING CONVECTION ALONG WARM FRONT/TRIPLE PT LOW.

NO WIDESPREAD SIGNIFICANT RAINFALL IS EXPECTED THROUGH THE END OF
THE WEEK.

&&

.TIDES/COASTAL FLOODING...
WITH APPROACHING FULL MOON...TIDAL DEPARTURES OF ONLY 3/4 TO 1 1/2
FT ARE NEEDED FOR MINOR COASTAL FLOODING BENCHMARKS TO BE REACHED
DURING THE LATE EVENING/NIGHT HIGH TIDES THE NEXT FEW DAYS. MINOR
BENCHMARKS COULD BE TOUCHED ACROSS THE MOST VULNERABLE
AREAS...PARTICULARLY ALONG THE SOUTH SHORE BAYS OF NASSAU
COUNTY AND WESTERN LI SOUND...MID TO LATE WEEK.

&&

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

&&

$$
SYNOPSIS...24/NV
NEAR TERM...TONGUE/NV
SHORT TERM...NV
LONG TERM...24
AVIATION...JMC/PW
MARINE...24/TONGUE/NV
HYDROLOGY...24/NV
TIDES/COASTAL FLOODING...


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.