Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 171938 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 338 PM EDT WED SEP 17 2014 .SYNOPSIS... HIGH PRESSURE REMAINS OVER THE REGION MOST OF THE TIME THROUGH SUNDAY. A WEAK COLD FRONT MOVES THROUGH THURSDAY. ANOTHER COLD FRONT MOVES THROUGH THE REGION TO START THE NEW WEEK. HIGH PRESSURE BUILDS BACK IN THE WAKE OF THE FRONT. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CYCLONIC NORTHWEST FLOW REMAINS ACROSS THE NORTHEAST THROUGH TONIGHT AS A WEAK UPPER AND MID LEVEL SHORT WAVE MOVES THROUGH THE SOUTHERN TIER OF CANADA FROM THE GREAT LAKES INTO QUEBEC AND NORTHERN NEW ENGLAND. WHILE AT THE SURFACE HIGH PRESSURE SLOWLY WEAKENS WITH THE APPROACH OF A COLD FRONTAL BOUNDARY. A DRY AIR MASS REMAINS IN PLACE TONIGHT WITH A LIGHT TO CALM NORTHWEST FLOW. WITH GENERALLY CLEAR CONDITIONS AND LIGHT WIND OUT LYING AREAS WILL RADIATE WELL AND QUICKLY. FOR OVERNIGHT LOWS LEANED TOWARD THE COOLER GFS GUIDANCE. THERE IS A MODERATE RISK OF RIP CURRENT DEVELOPMENT AT THE ATLANTIC BEACHES INTO THIS EVENING. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/... THE UPPER AND MID LEVEL SHORT WAVE CONTINUES TO TRACK EAST THROUGH SOUTHERN CANADA THURSDAY WHILE A WEAK COLD FRONT MOVES THROUGH THE AREA DURING THE DAY. UPPER LEVEL HEIGHT BEGIN TO RISE THURSDAY AFTERNOON AS ANOTHER CANADIAN AIR MASS BUILD TOWARD THE REGION. LITTLE MOISTURE AND LIFT WILL BE ASSOCIATED WITH THE FRONT AND ONLY AN INCREASE IN CLOUDS WILL ACCOMPANY THE PASSAGE. KEPT POPS NEAR ZERO WITH THE FRONT. AGAIN WILL BE A COOL DAY WITH NORTHERLY FLOW AND USED GFS GUIDANCE FOR HIGHS. THURSDAY NIGHT AND FRIDAY WILL REMAIN TRANQUIL AS AN UPPER RIDGE REMAINS ACROSS THE EASTERN THIRD OF THE UNITED STATES. AND AT THE SURFACE HIGH PRESSURE MOVES OUT OF SOUTH CENTRAL CANADA AND OFF THE NEW ENGLAND COAST. WITH A MUCH COOLER AIR MASS MOVING IN THE NAM AND GFS TEMPERATURE GUIDANCE SEEMS A LITTLE TOO HIGH SO USED THE COOLER ECS FOR TEMPERATURES THURSDAY NIGHT AND FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... WEEKEND STARTS OFF WITH HIGH PRESSURE PUSHING OFFSHORE UNDER A NEAR ZONAL FLOW. GENERALLY EXPECTING THE DRY CONDITIONS TO CONTINUE FRIDAY NIGHT INTO SATURDAY WITH THIS SET UP. PARTLY CLOUDY SKIES OVER EASTERN AREAS WITH SUBSIDENCE ALOFT...INCREASING CLOUD COVER TO THE SOUTH AND WEST WITH WEAK EMBEDDED VORT MAX RIDING THE FLOW. 12Z RUNS OF NAM/GFS SUGGESTIVE OF LIGHT PCPN FORMATION SAT AFTN THOUGH FAILING TO REALLY SEE ANY TRIGGER AT THE SFC OR ALOFT COMBINING WITH A STILL MOISTENING ATMO. SO WILL MAINTAIN DRY POPS HEADING INTO SAT NIGHT. CHANGING CONDITIONS BY SUNDAY AS THE NEXT AMPLIFYING MID/UPPER LEVEL TROUGH SWINGS SOUTH ACROSS THE GREAT LAKES REGION WITH SURFACE LOW PRESSURE TREKKING THROUGH SOUTHERN CANADA. FIRST THING OF NOTE FOR SUNDAY TO BE ADDRESSED IS THE FORMATION OF LOW PRESSURE FORMING OFF THE SOUTHEAST US WITH ASSOCIATED MID LEVEL ENERGY SWINGS NORTH AHEAD OF THE TROUGH. 12Z CMC BIT QUICKER WITH THE PROGRESSION...ALLOWING FOR THE PHASING OF THE DETACHED ENERGY WITH THE MAIN TROUGH DEVELOPING IN A MUCH DEEPER/STRONGER SYSTEM MOVING THROUGH THE NORTHEAST. FOR NOW...SIDED WITH A SOLUTION LEANING MORE TO THE ECMWF AND GFS...WHICH HAS THE LOW RIDING THE COLD FRONT AS IT MOVES THROUGH ON SOMETIME SUNDAY NIGHT INTO MONDAY...THEN LINGERING JUST OFFSHORE INTO MONDAY NIGHT AND FINALLY EXITING THE REGION BY TUES MORNING. CONCERNING POPS...INTRODUCED SLIGHT CHC BY SUN AFTN FOR EXTREME NORTHWEST AREAS RIGHT AHEAD OF THE FRONT...THEN SPREADING TO THE EAST SUN NIGHT AND MONDAY...THEN TAPERING OFF FROM WEST TO EAST BY 06Z TUES. ENOUGH MOISTURE SHOULD BE USHERED IN WITH THE SOUTHERLY FLOW AHEAD OF THE FRONT TO RESULT IN AT LEAST LIGHT SHOWERS FOR SOME TIME SUN NIGHT-MON. HOWEVER...UNCERTAINTY ON THE TIMING SO WILL MAINTAIN LOWER END CHC POPS. MODEL SOLUTIONS THEN COME BACK INTO DECENT AGREEMENT BY 12Z TUES...WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT...RESULTING IN DRY CONDITIONS FOR MID WEEK. PERIOD OF BELOW NORMAL TEMPS WILL BE SHORT LIVED WITH WAA ALONG THE SOUTHERLY FLOW PUSHING TEMPS BACK TO NEAR NORMAL LEVELS BY SAT. CAA WITH THE COLD FRONT MONDAY THROUGH MID WEEK WILL SEE TEMPS DROPPING A FEW DEGREES BELOW NORMAL ONCE AGAIN. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE THROUGH THE TAF PERIOD WILL KEEP VFR CONDITIONS IN PLACE. FEW-SCT CUMULUS DEVELOPMENT THROUGH REST OF TODAY MAINLY N/W OF CITY TERMINALS. SEA BREEZES WILL BE LIKELY WITH NORTH WINDS OF 5-10 KT BECOMING MORE SOUTHERLY. THERE IS SOME UNCERTAINTY OF A FEW HOURS WITH THIS TIMING. FOR EXAMPLE...RESIDUAL NORTHERLY FLOW COULD CAUSE SEA BREEZE TO HALT PROGRESS AND DELAY ENTERING OTHER TERMINALS AFTER KJFK. WINDS LIGHTEN AGAIN TONIGHT BEFORE INCREASING TO 5-10 KT FROM A GENERAL NORTHWEST DIRECTION EARLY THURSDAY. OVERALL...HIGH CONFIDENCE CATEGORY FORECAST AND MODERATE CONFIDENCE WITH WINDS. 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: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 1-2 HOURS. KLGA FCSTER COMMENTS: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 2-3 HOURS. KEWR FCSTER COMMENTS: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 2-3 HOURS. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 2-3 HOURS. KHPN FCSTER COMMENTS: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 1-2 HOURS. KISP FCSTER COMMENTS: WIND DIRECTION COULD BECOME QUITE VARIABLE BEFORE THE SEA BREEZE...WHICH ITSELF COULD BE OFF BY 2-3 HOURS. .OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... .THURSDAY-SUNDAY...VFR. .SUNDAY NIGHT-MONDAY...CHANCE OF MVFR OR BELOW WITH POSSIBLE SHOWERS. && .MARINE... WITH HIGH PRESSURE OVER THE WATERS TONIGHT INTO THURSDAY THE FLOW WILL BE RATHER LIGHT. A WEAK COLD FRONT DOES MOVE THROUGH THURSDAY AFTERNOON INTO THURSDAY EVENING. ANOTHER HIGH BUILDS IN FROM CANADA THURSDAY NIGHT INTO FRIDAY. A NORTHEAST FLOW AROUND THE HIGH INCREASES LATE THURSDAY NIGHT INTO FRIDAY. SOME GUSTS MAY APPROACH SMALL CRAFT LEVELS ON THE EASTERN OCEAN WATERS DURING FRIDAY. IN ADDITION TO THE FLOW A SOUTHEAST SWELL MAY ALLOW FOR SEAS ON THE OCEAN TO BUILD TO AROUND 5 FT DURING FRIDAY. GENERALLY EXPECTING SUB-SCA CONDITIONS THROUGH THE COMING WEEK. SEAS WILL ATTEMPT TO BUILD TO 5 FT ON THE OCEAN WATERS SUN-MON WITH THE PERSISTENT SOUTHERLY FLOW...BUT OVERALL SHOULD REMAIN AT 3-4 FT. && .HYDROLOGY... NO RAINFALL IS EXPECTED THROUGH THE FIRST HALF OF THE WEEKEND. NO SIGNIFICANT PRECIPITATION RESULTING IN HYDROLOGIC ISSUES IS EXPECTED SUNDAY THROUGH NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...SEARS/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...SEARS AVIATION...JM/PICCA MARINE...SEARS/MET HYDROLOGY...SEARS/MET

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