Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 240841 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 441 AM EDT SUN MAY 24 2015 .SYNOPSIS... BERMUDA HIGH PRESSURE PERSISTS THROUGH MIDWEEK. THE HIGH THEN MOVES FARTHER OUT INTO THE ATLANTIC AND WEAKENS ACROSS THE LOCAL REGION WITH MULTIPLE LOWS PASSING FROM THE GREAT LAKES INTO SOUTHEAST CANADA MID THROUGH LATE WEEK. THERE WILL BE A WEAKENING COLD FRONT ENTERING WEDNESDAY NIGHT AND STALLING WITHIN THE VICINITY ON THURSDAY WHILE FURTHER WEAKENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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ALOFT...THE JET STREAM WILL BE PUSHING NORTH DURING THE DAY WITH AN INCOMING LONGWAVE RIDGE FROM THE WEST. THE RIDGING WILL PROMOTE SUBSIDENCE...KEEPING MOSTLY SUNNY CONDITIONS DURING THE DAY TODAY. AT THE SURFACE...HIGH PRESSURE WILL SET UP OFFSHORE TODAY...ESSENTIALLY BECOMING A PERSISTENT BERMUDA HIGH. THE SOUTHWEST FLOW ACROSS THE REGION WILL REMAIN AND LIKELY INCREASE WITH ADIABATIC MIXING UP TO 875 TO 900 MB. GUSTS WILL BE IN THE 15 TO 20 KT RANGE. THE SEA BREEZE WILL BE MORE LIMITED DUE TO STRONGER SW BOUNDARY LAYER FLOW. THE 850 MB TEMPS HAVE ALREADY BEEN INCREASING AND ARE EXPECTED TO CONTINUE IN THIS TREND THROUGH THE DAY. THE MIXING WILL ALLOW FOR REMARKABLY WARMER TEMPERATURES COMPARED TO YESTERDAY. USED A MET/EKD BLEND OF TEMPERATURES TO REFLECT THE WARMER SIDE OF GUIDANCE WHICH VERIFIED PRETTY WELL THE PREVIOUS DAY WITH HIGH TEMPS. FOR THE ATLANTIC OCEAN BEACHES...THERE IS A MODERATE RISK FOR RIP CURRENTS.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
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FOR TONIGHT...THE SUBSIDENCE FROM THE RIDGE WILL STILL BE PROMINENT WITH MOSTLY CLEAR SKIES WITH A STRONG BERMUDA HIGH IN PLACE. THE SOUTHWEST FLOW WILL CONTINUE...MODERATING TEMPERATURES ACROSS LONG ISLAND. USED A BLEND OF MAV AND ECE FOR LOW TEMPS...AGAIN SIDING WITH A RELATIVELY WARMER SOLUTION. FOR MONDAY...THE 850MB TEMPERATURES INCREASE A FEW DEGREES...OVERALL EXHIBITING A STEADY RISING TREND COMPARED TO THE PREVIOUS DAY. LIKEWISE...EXPECTING HIGH TEMPS NEAR THE SURFACE TO BE A FEW DEGREES WARMER THAN THE PREVIOUS DAY. HOWEVER...AT THE IMMEDIATE COASTLINE...THE TEMPS ARE FORECAST TO BE NEARLY THE SAME AS THE PREVIOUS DAY. THE SOUTHWEST FLOW CONTINUES WITH STRONG HIGH PRESSURE OFFSHORE. MORE CLOUDS ARE EXPECTED BUT WEATHER IS EXPECTED TO REMAIN DRY WITH A WARM FRONT TO THE NORTH OF THE REGION. THIS WILL BE DRIVEN BY A MID TO UPPER LEVEL SHORTWAVE TRAVELING ALONG THE PERIPHERY OF THE RIDGE.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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THE RIDGE AND SURFACE HIGH REMAIN IN PLACE MONDAY NIGHT THROUGH WEDNESDAY NIGHT WITH A SOUTHWESTERLY FLOW KEEPING A WARM AND HUMID AIR MASS IN PLACE. FOR TUESDAY AND WEDNESDAY AFTERNOONS AND INTO THE EVENINGS EACH DAY THERE WILL BE A LOW CHANCE FOR SHOWERS AND THUNDERSTORMS AROUND THE PERIPHERY OF THE RIDGE AS WEAK SURFACE TROUGHS DEVELOP. THE AIR MASS SHOWERS AND THUNDERSTORMS WILL BE DIURNALLY DRIVEN WITH BUILD UP OF CAPE AND THEREFORE INSTABILITY. IF THE HIGH AND RIDGE ARE STRONGER AND REMAIN IN PLACE...THE INLAND AREAS MAY REMAIN DRY. FARTHER EAST IS MORE STABLE WHILE FARTHER WEST WILL BE MORE UNSTABLE AS THAT IS WHERE WARMER AIR WILL RESIDE SO CHANCES FOR ANY CONVECTION WILL BE HIGHER NORTH AND WEST OF NYC. AS A SHORTWAVE MOVES INTO THE RIDGE WEDNESDAY NIGHT INTO THURSDAY AFTERNOON AND WEAKENS FRIDAY THERE WILL BE BETTER CHANCES OF SHOWERS AND THUNDERSTORMS...AND FARTHER TO THE SOUTH AND EAST. HOWEVER...NOT HIGHLY CONFIDENT THAT THE RIDGE WEAKENS SIGNIFICANTLY AND KEPT POPS AT CHANCE. 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.
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&& .AVIATION /09Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE OFF OF THE MID ATLANTIC COAST WILL SLOWLY MOVE EWD THROUGH THE DAY TODAY. VFR THROUGH THE TAF PERIOD. A LIGHT SYNOPTIC SW FLOW INCREASES AGAIN AFTER SUNRISE. GUSTS TO AROUND 20 KT...OR IN THE LOWER 20S...ARE EXPECTED TO DEVELOP AND THIS WILL CAUSE SOME UNCERTAINTY IN WHETHER TRUE SEABREEZE DIRECTIONS AT KJFK/KLGA/KBDR/KGON/KISP CAN BE REALIZED IN THE AFTERNOON. HIGHEST LIKELIHOOD FOR TRUE SEABREEZE IS KJFK. WINDS LIGHTEN AFTER SUNSET TO UNDER 10 KTS. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .TONIGHT-MONDAY NIGHT...VFR. SW WINDS G15-20KT POSSIBLE MONDAY AFTERNOON. .TUESDAY-THURSDAY...MVFR OR LOWER POSSIBLE IN STRATUS AND/OR FOG LATE AT NIGHT/MORNING...OTHERWISE VFR. LOW CHC SHRA/TSTM NW OF NYC METRO EACH AFTN. COASTAL SEA BREEZES LIKELY EACH AFTERNOON...WITH S-SW WINDS G15-20KT POSSIBLE. && .MARINE...
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AN AREA OF HIGH PRESSURE WILL REMAIN EAST OF THE WATERS THROUGH THE MID WEEK PERIOD. PERSISTENT SOUTHWEST FLOW WILL PREVAIL. WINDS AT TIMES COULD APPROACH 20 TO 25 KTS OVER THE OCEAN WATERS... ESPECIALLY DURING EACH AFTERNOON. SEAS GRADUALLY BUILD TO 5 FEET OVER THE OCEAN WATERS...PROBABLY BEGINNING LATE MONDAY OR MONDAY NIGHT. THE LOCAL NON OCEAN WATERS SHOULD REMAIN JUST BELOW SCA CRITERIA THROUGH THE MID WEEK PERIOD. FOG/POOR VISIBILITIES WILL BECOME MORE LIKELY BY MID WEEK AND INTO LATE WEEK AT NIGHT AND EARLY MORNING.
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&& .FIRE WEATHER...
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SOUTHWEST FLOW TODAY GENERALLY 10 TO 20 MPH WILL HELP LOWER DEWPOINTS WITH VERTICAL MIXING. AS A RESULT...MINIMUM RELATIVE HUMIDITIES WILL BE NEAR 25 TO 30 PERCENT FOR MUCH OF THE REGION...SO THESE CONDITIONS WILL ENHANCE THE SPREAD AND GROWTH OF ANY FIRES THAT DEVELOP. THE EXCEPTION WILL BE FOR COASTAL CONNECTICUT...SOUTHERN QUEENS...NASSAU AND SUFFOLK COUNTIES...WHERE MORE ONSHORE FLOW WILL RESULT IN MINIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT FOR MOST LOCATIONS SO LOW LEVELS WILL NOT BE AS DRY HERE.
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&& .HYDROLOGY... NO SIGNIFICANT WIDESPREAD RAIN EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JM NEAR TERM...JM SHORT TERM...JM LONG TERM...JM/MET AVIATION...PW MARINE...PW FIRE WEATHER...JM HYDROLOGY...JM

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