Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 042259 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 659 PM EDT MON MAY 4 2015 .SYNOPSIS... HIGH PRESSURE REMAINS OVER THE ATLANTIC AS A COLD FRONT APPROACHES FROM THE NORTHWEST TONIGHT. THE COLD FRONT MOVES ACROSS THE AREA TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE BUILDS OVER THE REGION FOR THE MIDDLE TO THE END OF THE WEEK. A FRONTAL BOUNDARY PASSES NORTH OF THE AREA THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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TEMPERATURES WERE PRETTY MUCH RIGHT IN LINE WITH FORECAST VALUES BUT DEWPOINTS HAD TO BE ADJUSTED SLIGHTLY DOWNWARD. OTHERWISE...NO OTHER SIGNIFICANT CHANGES MADE TO THE FORECAST DATABASE WITH THE FORECAST REMAINING ON TRACK. MODELS REMAIN IN GOOD AGREEMENT WITH SFC HIGH PRESSURE DRIFTING EAST TONIGHT OVER THE WESTERN ATLANTIC AS A COLD FRONT APPROACHES FROM THE NW. THE FRONT SHOULD MOVE INTO THE NW PORTION OF THE CWA BETWEEN 6 AND 10Z OVERNIGHT. ALOFT...RIDGE AXIS MOVES EAST THIS EVENING...WITH ZONAL FLOW PREVAILING ACROSS THE NORTHEAST FOR THE REMAINDER OF THE NIGHT. CLOSED LOW WELL UP IN EASTERN CANADA MOVES EAST. A GENERAL SW FLOW WILL DECREASE THROUGHOUT TONIGHT. MOSTLY CLEAR CONDITIONS WILL YIELD TO MORE CLOUDS AHEAD OF THE FRONT LATE TONIGHT. MESOSCALE MODELS INCLUDING ARW AND WRF-NMM SHOW SHOWERS ALONG AND AHEAD OF THE FRONT DISSIPATING AS THEY NEAR THE AREA LATE TONIGHT. NCEP MODELS INCLUDING SREF MEAN INDICATE LIGHT QPF VIA WEAKENING SHOWER ACTIVITY BEFORE 10Z TONIGHT...SO WILL MAINTAIN MINIMAL POPS FOR NW ZONES AS THEY NEAR THE AREA. ABOVE NORMAL TEMPS EXPECTED OVERNIGHT...WITH LOWS RANGING FROM AROUND 50 ACROSS THE INTERIOR TO THE LOWER 60S IN AND AROUND NYC.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... ZONAL FLOW INITIALLY WILL GIVE WAY TO A LATE DAY AND OVERNIGHT 500- 700 HPA TROUGH. THIS FEATURE IS MORE PRONOUNCED IN THE 12Z NAM. ANY MORNING ISOLATED SHOWER ACTIVITY WILL GIVE WAY TO SLIGHTLY HIGHER COVERAGE DURING THE AFTERNOON AND INTO THE EVENING HOURS. NAM...WRF-NMM SHOW CONVECTION UPSTREAM IN PA RIDING ALONG THE RIDGE EARLY IN THE DAY APPROACHING OUR REGION LATE. IT APPEARS THAT THE BETTER COVERAGE WILL BE JUST SOUTH OF THE FRONT FROM NE NJ/NYC SOUTHWARD. ECMWF/GFS AND SREF MEAN SUPPORT LESS COVERAGE WITH LOWER POPS. AT THIS TIME...WILL NOT STRAY TOO FAR FROM PREVIOUS FORECAST...RAISING POPS SLIGHTLY BUT CAPPING THEM IN THE CHANCE RANGE. HIGHEST POPS SW ZONES...AND LOWEST NE. THIS SUPPORTED BY LATEST DAY 2 SPC OUTLOOK FOR THUNDERSTORMS AS MARGINAL INSTABILITY IS PRESENT TO THE SOUTH AND WEST...IF NOT A LOT OF UPPER SUPPORT. DEPENDING ON THE LOCATION OF THE FRONT...ANY LINGERING SHOWER OR TSTM ACTIVITY WILL REMAIN OR PASS SOUTH TUESDAY NIGHT...WITH POPS LOWERING THROUGH THE NIGHT. EXPECT HIGH PRESSURE TO THE NORTH TO PUSH THE FRONT JUST TO OUR SOUTH DURING THE EVENING HOURS. ANOTHER UNSEASONABLY WARM DAY IS ON TAP DESPITE THE CLOUDS. READINGS MAY BE SLIGHTLY LOWER...BUT STILL EXPECT 80 DEGREES AWAY FROM THE WATER...WITH NEAR 70 OVER EASTERN SECTIONS OF THE CWA. WITH THE FRONT IN OUR PROXIMITY...WINDS WILL NOT BE AS STRONG...SO LESS DISPARITY IN TEMPS FROM WHAT OCCURRED EARLIER TODAY. TUESDAY LOWS WILL RUN ABOVE NORMAL...BUT WILL BE A FEW DEGREES COOLER THAN TONIGHT`S EXPECTED TEMPERATURES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... COLD FRONT CONTINUES TO MOVE SOUTH AND EAST OF THE AREA WEDNESDAY MORNING. JUST A SLIGHT CHANCE FOR SOME LINGERING SHOWERS OVER SOUTHEAST ZONES IN THE MORNING...AND THEN CONDS CLEAR OUT FOR THE AFTERNOON. HIGH PRES BOTH AT THE SURFACE AND ALOFT WILL BUILD EAST AND OVER THE AREA FOR THE MIDDLE TO THE END OF THE WEEK...AND THEN THE HIGH MOVES OFFSHORE ON FRIDAY. DRY CONDS WITH NEAR TO ABOVE NORMAL TEMPS THROUGH THE END OF THE WORK WEEK WITH HIGHS GENERALLY IN THE 70S...WARMING INTO THE LOWER 80S ACROSS THE INTERIOR BY FRIDAY. WITH A LIGHT PRES GRADIENT...CAN EXPECT AFTERNOON SEA BREEZES...RESULTING IN COOLER AFTERNOON TEMPS FOR COASTAL AREAS. LOW PRES SLOWLY TRACKS THROUGH THE GREAT LAKES AND INTO THE OHIO VALLEY FOR THIS WEEKEND...AND A FRONTAL BOUNDARY WILL EXTEND FROM THIS SYSTEM AND MOVE WELL NORTH OF THE REGION. SATURDAY SHOULD BE DRY...BUT THE FRONT WILL BEGIN TO SAGE TO THE SOUTH FOR SUNDAY AND MONDAY...AND SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS ARE POSSIBLE FOR THE START OF THE NEW WEEK. WILL CAP POPS AT LOW CHANCE FOR NOW...WITH HIGHEST POPS ACROSS THE INTERIOR...WHICH WILL BE CLOSER TO THE FRONT. NEAR TO ABOVE NORMAL TEMPS WILL LIKELY CONTINUE FOR THE WEEKEND AND START OF THE NEW WEEK. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR THROUGH TONIGHT AS HIGH PRESSURE REMAINS OFF THE MID ATLANTIC COAST. A COLD FRONT WILL APPROACH FROM THE NW LATE TONIGHT INTO TUE. STRONGER LATE AFTERNOON SEA BREEZES ARE IN PROGRESS AT NYC METROS AND KISP/KHPN...WITH BRISK SW WINDS AT KSWF AS WELL. SEA BREEZES AT KBDR/KGON HAVE REMAINED RELATIVELY LIGHT AND SHOULD REMAIN SO INTO EARLY EVENING. SOUTHERLY WINDS SHOULD GRADUALLY DIMINISH THIS EVENING...BACK SW 5- 10 KT LATE TONIGHT...THEN SHIFT W FROM NYC METRO TERMINALS NORTH/WEST AS THE FRONT ENTERS THE REGION AND THEN STALLS. LLWS EXPECTED TONIGHT AT KISP/KGON...WITH SW FLOW INCREASING TO 45 KT AROUND 1 KFT AGL. LOW CHANCE OF NYC METRO SEEING THIS FROM LATE EVENING ON AS WELL. BKN VFR CIGS ARRIVE TUE MORNING WITH THE FRONT...ALONG WITH POSSIBLE MVFR VSBY IN SCT SHOWERS. 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: NO UNSCHED AMD EXPECTED. LOW CHANCE FOR LLWS LATE EVENING AND OVERNIGHT. KLGA FCSTER COMMENTS: NO UNSCHED AMD EXPECTED. LOW CHANCE FOR LLWS LATE EVENING AND OVERNIGHT. KEWR FCSTER COMMENTS: NO UNSCHED AMD EXPECTED. KTEB FCSTER COMMENTS: NO UNSCHED AMD EXPECTED. KHPN FCSTER COMMENTS: NO UNSCHED AMD EXPECTED. KISP FCSTER COMMENTS: NO UNSCHED AMD EXPECTED. .OUTLOOK FOR 18Z TUE THROUGH SAT... .TUE AFTERNOON/EVENING...MVFR CONDS POSSIBLE IN SCT SHOWERS. AN ISOLD TSTM POSSIBLE. .LATE TUE NIGHT-SAT...VFR. && .MARINE...
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SW GUSTS NEAR 20-25 KT THIS EVENING ACROSS THE NEARSHORE WATERS WILL GRADUALLY LOWER THIS EVENING. THE 25KT GUSTS ARE EXPECTED TO BE GENERALLY OCCASIONAL IN FREQUENCY. IN ADDITION...OCEAN SEAS PER WAVE WATCH III BUILD TO 5 FT TONIGHT WHERE SCA REMAINS IN EFFECT. ELSEWHERE...SOUTH TO SOUTHWEST FLOW WILL LIGHTEN AS THE NIGHT PROGRESSES. A COLD FRONT APPROACHES AND TRACKS JUST NORTH OF THE WATERS TUESDAY...AND SETTLES OVERHEAD TUESDAY NIGHT. WINDS LIGHTEN AND WILL EVENTUALLY SHIFT AROUND TO THE N/NE LATE TUESDAY NIGHT...DEPENDING ON THE EXACT LOCATION OF THE FRONT.
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&& .FIRE WEATHER...
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GUSTY SW WINDS AND LOW RELATIVE HUMIDITY WARRANTS RED FLAG WARNING INTO THE EVENING FOR WESTERN ZONES. SPECIAL WEATHER STATEMENT ELSEWHERE FOR MARGINAL CONDITIONS. INTERIOR AREAS WILL LOWER WITH WINDS FIRST THIS EVENING WITH GUSTS EXPECTED TO LOWER TO BELOW 25 MPH AFTER 8 PM. FARTHER EAST INTO NYC AND ACROSS THE COAST...IT WILL TAKE A LITTLE LONGER BUT RH IS EXPECTED TO RISE ABOVE 30 PERCENT WITH THE ONSHORE FLOW. WINDS DIMINISH OVERNIGHT...AND HUMIDITY LEVELS RISE...SO DO NOT FORESEE ANY FIRE RELATED HEADLINES THROUGH TUESDAY. WITH HIGH PRES AND A LIGHT PRES GRADIENT OVER THE WATERS FOR THE MIDDLE TO THE END OF THE WEEK...CAN EXPECT TRANQUIL CONDS DURING THE LONG TERM PERIOD. SOME AFTERNOON GUSTS TO 20 KT POSSIBLE ACROSS THE NEAR SHORE WATERS DUE TO SEA BREEZES.
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&& .HYDROLOGY... GENERALLY EXPECT FROM 1/10 TO 1/4 INCH OF BASIN AVERAGE RAINFALL TUESDAY AND TUESDAY NIGHT FROM SCATTERED SHRA/ISOLD TSTMS. HOWEVER CANNOT COMPLETELY RULE OUT LOCALLY HEAVY RAINFALL IN ANY STRONGER CONVECTION. IF THIS DOES OCCUR OVER AN AREA...THEN LOCALIZED MINOR FLOODING OF URBAN AND POOR DRAINAGE AREAS WOULD BE POSSIBLE. THIS IS A LOW PROBABILITY THOUGH. DRY CONDITIONS ARE EXPECTED WEDNESDAY THROUGH THE WEEKEND. NEXT CHANCE FOR SHRA/TSRA WILL BE ON SUNDAY AND MONDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NYZ067>075- 176>179. NJ...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NJZ002-004- 006-103>108. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...JM/PW SHORT TERM...PW LONG TERM...MPS AVIATION...GOODMAN MARINE...JM/MPS/PW FIRE WEATHER... HYDROLOGY...MPS/PW

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