Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 250246 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1046 PM EDT SUN MAY 24 2015 .SYNOPSIS... THE BERMUDA HIGH REMAINS IN PLACE THROUGH THE MIDDLE OF THE WEEK. THE HIGH THEN MOVES FARTHER OUT INTO THE ATLANTIC AND WEAKENS ACROSS THE LOCAL REGION WITH MULTIPLE LOWS PASSING FROM THE GREAT LAKES INTO SOUTHEASTERN CANADA FROM MID TO LATE WEEK. A FRONTAL BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... FORECAST IS ON TRACK. MINOR ADJUSTMENTS NEEDED TO T/TD AND SKY OVERNIGHT. CIRRUS CONTINUES TO WORK ITS WAY OVER THE TOP OF THE RIDGE TO OUR WEST OVER THE TRI- STATE...AND LOOKING UPSTREAM DO NOT EXPECT MUCH IN THE WAY OF BREAKS/DISSIPATION TONIGHT. SO GOING WITH A PARTLY TO MOSTLY CLOUDY FORECAST FOR TONIGHT. A BLEND OF MAV/MET/ECS GUIDANCE WAS USED FOR LOWS...WITH VALUES EXPECTED TO BE AROUND 5 DEGREES ABOVE NORMAL. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... A DEEP LAYERED RIDGE AXIS BUILDS OVER THE AREA MONDAY...THEN SLIDES TO THE EAST MONDAY NIGHT. THE ASSOCIATED SUBSIDENCE SHOULD KEEP THINGS DRY. DO EXPECT SOME BREAKS IN THE CIRRUS SO GOING WITH A MOSTLY CLOUDY/PARTLY SUNNY FORECAST. FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 975-850 HPA PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF WARMER MET/MAV/EKD GUIDANCE. HIGHS SHOULD BE GENERALLY A FEW DEGREES WARMER THAN TODAY...WHICH WOULD PLACE THEM AROUND 5-10 DEGREES ABOVE NORMAL. SHOULD SEE GUSTY WINDS WITH SEABREEZE AGAIN MONDAY AFTERNOON...WITH GUSTS UP TO 25 TO 30 MPH...WITH ISOLATED GUSTS TO 35 MPH POSSIBLE NEARSHORE. A 40-45KT JET AT 1000 FT WILL HELP TO ENHANCE THE GUSTINESS OF THE SEABREEZE. MAIN UNCERTAINTY FOR MONDAY NIGHT IS WHETHER ANY LOW CLOUDS/FOG FORM WITH THIRD NIGHT OF ONSHORE FLOW. NAM BUFKIT SOUNDINGS HAVE BACKED AWAY FROM THIS IDEA...BUT STILL SHOULD SEE PLENTY OF DEBRIS CIRRUS WORKING ITS WAY UP THE BACKSIDE OF THE RIDGE - SO WENT WITH PARTLY TO MOSTLY CLOUDY SKY COVER. FOR LOWS MONDAY NIGHT A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES WAS USED...WITH READINGS FORECAST TO BE AROUND 5-10 DEGREES ABOVE NORMAL. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE ATLANTIC BEACHES MEMORIAL DAY. && .LONG TERM /TUESDAY THROUGH SUNDAY/... AN UPPER EAST COAST RIDGE REMAINS IN PLACE TUESDAY INTO WEDNESDAY THEN BEGINS TO WEAKEN WEDNESDAY NIGHT INTO FRIDAY AS A SOUTHERLY STREAM SHORTWAVE MOVES INTO THE RIDGE. MUCH OF THE AREA REMAINS DRY WITH THE BERMUDA HIGH WELL ESTABLISHED TUESDAY AND WEDNESDAY. DIURNALLY DRIVE AIR MASS THUNDERSTORMS WILL BE POSSIBLE TUESDAY AND WEDNESDAY AFTERNOONS AND EVENINGS ACROSS THE INTERIOR...AROUND THE HIGH AS ENERGY MOVES INTO NORTHERN NEW ENGLAND AND SOUTHERN CANADA. AS THE SHORTWAVE MOVES INTO THE RIDGE THE UPPER FLOW BECOMES MORE WESTERLY...ALLOWING A COUPLE OF WAVES TO MOVE ACROSS THE REGION THURSDAY AND FRIDAY. THIS RESULTS IN MORE WIDESPREAD PRECIPITATION FOR A LONGER PERIOD OF TIME THURSDAY AND FRIDAY. A WESTERLY FLOW PERSISTS INTO NEXT WEEKEND WITH THE NORTHERN STREAM MORE DOMINANT ACROSS THE SOUTHERN TIER OF CANADA WHILE THE SOUTHERN FLOW WEAKENS CONSIDERABLY ACROSS THE CONTINENTAL UNITED STATES. THERE IS EXPECTED TO BE A BRIEF BREAK IN THE PRECIPITATION THEN WITH THE WEAK FLOW THE NEXT WAVE AND SURFACE FRONTAL BOUNDARY BECOME NEARLY STATIONARY ACROSS THE AREA SATURDAY INTO SUNDAY. FINALLY WITH INCREASING LOW LEVEL MOISTURE...WITH DEW POINTS RISING...AND A SOUTH TO SOUTHWEST FLOW THERE WILL BE THE INCREASING LIKELIHOOD OF STRATUS AND FOG DEVELOPING AT NIGHT INTO EARLY MORNING MID TO LATE IN THE WEEK. MAY BE MORE OF A STRATUS DECK ACROSS LONG ISLAND AND POSSIBLY COASTAL CONNECTICUT WITH THE FLOW MORE SOUTHWESTERLY THAN SOUTH. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE REMAINS TO THE EAST OF THE AREA FOR THE NEXT SEVERAL DAYS. VFR THROUGH THE TAF PERIOD. S-SW FLOW LESS THAN 10 KT ALL TERMINALS OVERNIGHT. S-SW WINDS INCREASE AFT 12Z MON WITH GUSTS RETURNING AS WELL. GUSTS 20-30KT EXPECTED BY LATE AFTN. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .MONDAY NIGHT...VFR. WINDS DIMINISHING. .TUESDAY-FRIDAY...MVFR OR LOWER POSSIBLE IN STRATUS AND/OR FOG LATE AT NIGHT/MORNING...OTHERWISE VFR. LOW CHANCE SHRA/TSTM EACH AFTERNOON...BUT MOSTLY NW OF CITY TERMINALS TUE AND WED. COASTAL SEA BREEZES LIKELY EACH AFTERNOON...WITH S-SW WINDS G15-20KT POSSIBLE. && .MARINE... SUB-SMALL CRAFT CONDITIONS ARE EXPECTED ON ALL WATERS THROUGH MONDAY MORNING...WITH A PERSISTENT SW FLOW. WINDS INCREASE MONDAY AFTERNOON/NIGHT IN RESPONSE TO A TIGHTENING PRESSURE GRADIENT AND THE PASSAGE OF A 40-45 KT JET AT 1000 FT. AT THE SAME TIME WILL BE FAIRLY DEEPLY INVERTED...WHICH WILL MINIMIZE THE AMOUNT OF THIS JET THAT MIXES DOWN...BUT WITH THE WIND MAX AT OR JUST UNDER THE NOSE OF THE RIDGE...MORE MIXING COULD OCCUR IN THIS SCENARIO THAN ONE WOULD TYPICALLY EXPECT. BASED ON THIS HAVE ISSUED A SMALL CRAFT ADVISORY FOR THE COASTAL OCEAN WATERS AND THE SOUTH SHORE BAYS OF LONG ISLAND FROM 18Z MONDAY-10Z TUESDAY WITH GUSTS OF 25-30KT. SEAS ON THE COASTAL OCEAN WATERS SHOULD BUILD TO 4-6 FT AS WELL. ON THE REMAINDER OF THE WATERS MONDAY AFTERNOON-NIGHT...GIVEN THE FORECAST TRACK OF THE LOW LEVEL JET...EXPECTING MAINLY GUSTS TO 20 KT...WITH SOME OCCASIONAL GUSTS TO 25 KT AT THIS TIME. HOWEVER...CANNOT RULE OUT THAT 25 KT GUSTS END UP BEING MORE FREQUENT THAN CURRENTLY EXPECTED ON THE SOUND/HARBOR/EASTERN BAYS OF LONG ISLAND MONDAY AFTERNOON/NIGHT. A PERSISTENT SOUTHWEST FLOW WILL CONTINUE TUESDAY THROUGH THURSDAY WITH WIND SPEEDS UNDER SMALL CRAFT LEVELS. HOWEVER...NEARSHORE WIND GUSTS DURING THE AFTERNOONS TUESDAY AND WEDNESDAY COULD APPROACH SMALL CRAFT LEVELS. ON GOING SMALL CRAFT SEAS TUESDAY MORNING CONTINUE THROUGH MUCH OF THURSDAY. AS HIGH PRESSURE WEAKENS OVER THE WATERS AND A FRONT APPROACHES FROM THE WEST WIND SPEEDS ARE EXPECTED TO DIMINISH THURSDAY INTO THURSDAY NIGHT...AND SEAS WILL SLOWLY SUBSIDE TO BELOW 5 FT THURSDAY NIGHT. SUB SMALL CRAFT SEAS REMAIN INTO FRIDAY NIGHT AS A WEAK PRESSURE GRADIENT REMAINS ACROSS THE WATERS. FOG WILL BECOME MORE LIKELY BY MID WEEK AND INTO LATE WEEK...ESPECIALLY AT NIGHT AND INTO THE EARLY MORNING. && .FIRE WEATHER... RELATIVE HUMIDITIES WILL BE 10-15 PERCENT HIGHER ON MON THAN TODAY...BUT WINDS WILL BE 10-15 MPH STRONGER...INCLUDING THE GUSTS. IF DEEPER MIXING OCCURS THAN IS CURRENTLY FORECAST...THEN THE POSSIBILITY OF ENHANCED RISK OF FIRE SPREAD COULD BE REALIZED MONDAY AFTERNOON AND EVENING AS WELL. && .HYDROLOGY... IT WILL BE DRY THROUGH AT LEAST MONDAY NIGHT. NO SIGNIFICANT WIDESPREAD RAIN IS EXPECTED TUESDAY THROUGH SUNDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO 6 AM EDT TUESDAY FOR ANZ345-350-353-355. && $$

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