Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 301742 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 142 PM 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/... FCST UPDATED TO INCLUDE SEVERE TSTM WATCH 372...IN EFFECT UNTIL 8 PM FOR ORANGE AND PASSAIC COUNTIES. CLUSTER OF STORMS IN ERN PA HAS ALREADY PROMPTED WARNINGS...AND MAY DO THE SAME IN OUR FAR WRN REACHES AS PARTIAL CLEARING WORKS ITS WAY INTO THESE AREAS AND QUICKLY DESTABILIZES THE AIR MASS AHEAD OF THE STORMS. SOME CONCERN FOR AN ISOLD TORNADO AS WELL GIVEN PROXIMITY OF WARM FRONT AND RESULTANT LOW LEVEL VEERING OF WINDS. SHOWERS AND TSTMS EXPECTED TO REMAIN MAINLY IN THE WATCH AREA THIS AFTERNOON...THUS KEPT INCREASED POP FROM PREV SHORT TERM FCST AND LOWERED THEM TO NONE FOR EAST OF THE HUDSON. HRRR AND SPC CONVECTION-ALLOWING MODELS /CAMS/ SUPPORT THE FCST FOR CONVECTION REMAINING WEST OF THE HUDSON THROUGH THIS AFTERNOON. OTHER CHANGE WAS TO SKY COVER...WHICH IS CLEAR EAST. SOME CLOUDS SHOULD SPILL INTO LONG ISLAND AND CT...BUT STILL A MOSTLY SUNNY DAY THERE. NYC IS EXPECT TO BECOME CLOUDY. 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 EASTERN PA AND INTO NW NJ/SE NY THIS AFTERNOON. CLOUD COVER ACROSS NYC METRO AND POINTS N&W...AND GUSTY S-SE FLOW WILL KEEP TEMPS IN THE UPPER 70S/LOWER 80S IN MOST PLACES. A MODERATE RIP CURRENT RISK CONTINUES THIS AFTERNOON WITH ONSHORE FLOW AND LINGERING 2-FT S SWELLS. && .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...CANNOT 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 AIR MASS. 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 /18Z TUESDAY THROUGH SUNDAY/... 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 KT 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 KT BY 17-19Z. KLGA FCSTER COMMENTS: OCCASIONAL TO FREQUENT GUSTS 15 TO 20 KT 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... NEAR SHORE WINDS 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 BLW 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 INCH OR MORE 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...GOODMAN SHORT TERM...NV LONG TERM...24 AVIATION...JMC/PW MARINE...24/TONGUE/NV HYDROLOGY...24/NV TIDES/COASTAL FLOODING...

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