Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 191047 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 647 AM EDT FRI SEP 19 2014 .SYNOPSIS... CANADIAN HIGH PRESSURE SLIDES EAST THROUGH NEW ENGLAND TODAY AND THEN OFF THE NORTHEAST COAST TONIGHT INTO SATURDAY. LOW PRESSURE WILL TRACK ACROSS SOUTHEAST CANADA SATURDAY NIGHT AND SUNDAY...DRAGGING A COLD FRONT ACROSS THE AREA SUNDAY NIGHT. MEANWHILE...ANOTHER AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRACK NORTHWARD...PASSING SOUTHEAST OF THE AREA. HIGH PRESSURE BUILDS BACK IN FOR MONDAY AND REMAINS IN CONTROL THROUGH THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INTENSE SHORTWAVE MOVES THROUGH NORTHERN NEW ENGLAND EARLY THIS MORNING WITH WEAKER ENERGY PASSING THROUGH THE AREA THROUGH THE MORNING. UPPER FLOW FLATTENS LATE IN THE DAY. GUSTY NE WINDS IN WAKE OF COLD FRONTAL PASSAGE THIS MORNING WITH GLANCING SHOT OF CAA IN IT WAKE. WINDS GRADUALLY VEER TO THE E THIS AFTERNOON AND WEAKEN A BIT AS CANADIAN HIGH PRESSURE SLIDES THROUGH NEW ENGLAND. MOISTURE TRAPPED UNDER POST-FRONTAL INVERSION RESULTING IN SCT-BKN STRATO- CU DECK EARLY THIS MORNING. THIS STRATUS DECK SHOULD CONTINUE TO SINK SOUTH THROUGH THE MORNING...AND GRADUALLY ERODE THROUGH THE MORNING AS DRIER AIR ADVECTS IN. SCATTERED INSTABILITY CLOUDS LIKELY RETURN THIS AFTERNOON ACROSS INTERIOR WITH DEVELOPING RETURN FLOW AND STRONG SUBSIDENCE INVERSION. TEMPS WILL RUN A GOOD 10 OR SO DEGREES BELOW NORMAL UNDER FRESH CANADIAN AIRMASS WITH HIGH TEMPS IN THE 60S AREAWIDE...EVEN SOME UPPER 50S INTERIOR. THERE IS GENERALLY A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN FACING BEACHES TODAY. NE WINDS AND ENE WIND WAVES WILL PROMOTE A STRONG LONGSHORE CURRENT AND MODERATE RIP RISK. EAST FACING SHORELINES AND THE EAST SIDE OF FIXED STRUCTURES WILL SEE AN ENHANCED RISK OF RIP CURRENTS...BUT OVERALL THIS WOULD A LOCALIZED THREAT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... ZONAL UPPER FLOW EARLY...GIVE WAY TO EAST COAST RIDGING AS NORTHERN STREAM DIGS INTO THE GREAT LAKES. AT THE SURFACE...CANADIAN HIGH PRESSURE CONTINUES TO SLIDE WELL OFFSHORE WITH RETURN FLOW DEVELOPING. STRATUS DEVELOPMENT POSSIBLE LATE TONIGHT...PARTICULARLY ACROSS NYC METRO AND POINT W/NW...WITH RETURN FLOW TRAPPING MOISTURE UNDER SUBSIDENCE INVERSION. WITH POTENTIAL FOR CLOUD COVER AND ONSHORE FLOW TEMPS LIKELY DONT BOTTOM OUT...BUT STILL RUN SEVERAL DEGREES BELOW SEASONABLE. TEMPS IN THE 50S ALONG THE COAST...AND 40S INTERIOR. GUSTY SE WAA FLOW ON SATURDAY WHICH SHOULD ALLOW FOR A MODERATION IN T/TD. MODELS SIGNALING SOME LIGHT PRECIP DEVELOPING IN RETURN FLOW...BUT WITH RATHER DRY SOUNDINGS AND LACK OF FORCING THIS MAY INDICATE POTENTIAL FOR STRATUS TO LINGER INTO THE AFTERNOON UNDER A LIFTING BUT LINGERING SUBSIDENCE INVERSION. TEMPS MODERATING TO NEAR SEASONABLE LEVELS WITH NOTICEABLE INCREASE IN HUMIDITY BY LATE DAY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE H5 FLOW THROUGH THE WEEKEND. TIMING AND AMPLITUDE DIFFERENCES THEN COME INTO PLAY THEREAFTER. ONE OTHER ELEMENT THAT BEARS WATCHING IS HOW QUICKLY THE DEVELOPING LOW OFF THE SE COAST IS PICKED UP BY THE DIGGING TROUGH. THERE SEEMS TO BE LARGE DISAGREEMENT WITH THIS LEADING TO HIGH VARIABILITY IN THE SYSTEMS FORWARD SPEED AND TRACK. SINCE THERE IS SUCH HIGH SPREAD AMONGST THE GUIDANCE WON`T GO INTO MUCH DETAILS AT THIS POINT...BUT POPS MIGHT NEED TO BE INCREASED SAT NIGHT INTO SUN AHEAD OF THE COLD FRONT AS MOISTURE STREAMS IN FROM THIS SYSTEM. IT COULD ALSO REMAIN FAR ENOUGH OFFSHORE KEEPING ALL PCPN THERE AS WELL. HAVE ADDED SCHC POPS FROM AREAS E OF FAIRFIELD COUNTY CT AND NASSAU COUNTY N NY FOR NOW AS GUIDANCE HAS BEEN INDICATING THIS AT TIMES OVER THE LAST FEW DAYS. OTHERWISE...THE DIGGING TROUGH SLOWS UP OVER THE EAST COAST DUE TO DOWNSTREAM RIDGING...BUT STILL IS PROGRESSIVE ENOUGH FOR THE SFC COLD FRONT TO PUSH E OF THE AREA SUN NIGHT. DECENT SHORTWAVE ACCOMPANIES THE FRONT ALOFT...BUT IT SHOULD BE A FAIRLY QUICK SHOT OF RAIN WITH A SOMEWHAT MOISTURE STARVED ATMOSPHERE. THE NAM HAS BEEN DISCOUNTED AS IT IS THE ONLY SOLN THAT DEVELOPS A WAVE IN SRN NEW ENGLAND AND IS A SLOW OUTLIER WITH THE WAVE OFF THE SE COAST. THE SHORTWAVE ALSO PIVOTS INTO NEW ENGLAND DURING THE EVE TAKING THE BEST DYNAMICS WITH IT. HIGHEST CHCS OF PCPN WILL BE WEST OF THE HUDSON RIVER. HAVE ALSO ADDED SCHC TSTMS SUN AFTN/NIGHT WITH MARGINAL INSTABILITY POSSIBLE. HIGHS SUN ARE EXPECTED TO BE SEVERAL DEGREES ABOVE NORMAL WITH INCREASING HUMIDITY LEVELS. THE FRONT IS EXPECTED TO CLEAR THE AREA BY MON MORNING...FOLLOWED BY THE TROF AXIS MON EVE. DEEP LAYERED RIDGING THEN BUILDS FROM THE PLAINS RESULTING IN DRY AND SEASONABLE WEATHER THROUGH THE REMAINDER OF THE WEEK. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE OVER EASTERN CANADA BUILDS SE AND OFF THE NEW ENGLAND COAST BY THIS EVENING. THIS WILL RESULT IN NLY WINDS VEERING AROUND TO THE E/SE BY LATE THIS AFT/EVE. SOME EARLY GUSTS UP TO 20 KT POSSIBLE THROUGH 15Z. FORECAST DILEMMA HINGES ON THE DEVELOPMENT OF A STRATUS DECK AROUND 3-4 KFT. PREFERENCE IS TO HOLD OFF AT THIS TIME DUE TO DRY LOW LEVELS. THIS MAY BECOME MORE OF A FACTOR TONIGHT. THERE IS SOME GUIDANCE THOUGH WHICH DEVELOPS THESE CLOUDS AS EARLY AS THIS MORNING. 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: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. KLGA FCSTER COMMENTS: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. KEWR FCSTER COMMENTS: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. KHPN FCSTER COMMENTS: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. KISP FCSTER COMMENTS: POSSIBLE MVFR/VFR CIG...MAINLY AFT/EVE HOURS. .OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY... .SATURDAY-SUNDAY...POSSIBLE MVFR CONDITIONS EACH MORNING IN FOG/CLOUDS...IMPROVING TO VFR BY 15Z. .SUNDAY NIGHT-MONDAY...CHANCE OF MVFR OR BELOW WITH SCATTERED SHOWERS. G20-25 KT MON. .MONDAY NIGHT-TUESDAY...VFR. && .MARINE... MARGINAL NE SCA WINDS THIS MORNING WILL HAVE SEAS CONTINUE TO BUILD TO 4 TO 6 FT ACROSS OCEAN WATERS. AS THE CENTER OF THE HIGH MOVES OFF THE NORTHEAST COAST THIS AFTERNOON WINDS EXPECTED TO VEER TO A MORE EASTERLY DIRECTION AND WEAKEN A BIT. MARGINAL 5 FT SEAS LIKELY TO CONTINUE AS FETCH BECOMES MORE FAVORABLE. WINDS CONTINUE TO VEER TO SE TONIGHT INTO FRIDAY. SUB SCA WINDS AND DIMINISHING RESIDUAL E SWELLS FROM EDOUARD SHOULD ALLOW SEAS TO FALL JUST BELOW SCA. WINDS ARE EXPECTED TO REMAIN BELOW SCA LEVELS SAT NIGHT INTO MID WEEK. SEAS ON THE OCEAN WATERS MAY BUILD TO MARGINAL SCA LEVELS BEHIND A COLD FRONT SUN NIGHT INTO MON. SUB-ADVSY CONDS ARE THEN EXPECTED UNTIL LATE TUE NIGHT INTO WED WITH AN INCREASING NLY FLOW. SCA SEAS ON THE OCEAN ARE AGAIN POSSIBLE. && .HYDROLOGY... NO RAINFALL IS EXPECTED THROUGH SUNDAY. LESS THAN 1/2 INCH OF RAINFALL IS EXPECTED WITH THE COLD FRONTAL PASSAGE SUN NIGHT. DRY WEATHER THEN EXPECTED FOR THE REST OF THE WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ350-353- 355. && $$ SYNOPSIS...24/NV NEAR TERM...NV SHORT TERM...NV LONG TERM...24 AVIATION...DW MARINE...24/NV HYDROLOGY...24/NV

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