Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 221019 CCA AFDOKX AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE NEW YORK NY 516 AM EST SAT NOV 22 2014 .SYNOPSIS... HIGH PRESSURE SLIDES OFF THE MID ATLANTIC COAST THROUGH TONIGHT...MEANWHILE...AN UPPER LEVEL DISTURBANCE CROSSES THE AREA TONIGHT AS WELL. A WARM FRONT APPROACHES FROM THE SOUTHWEST SUNDAY...THEN LIFTS TO OUR NORTH SUNDAY NIGHT AND MONDAY MORNING. A COLD FRONT THEN FOLLOWS BEHIND IT MONDAY NIGHT. AN AREA OF LOW PRESSURE DEVELOPS ALONG THE FRONT ALONG THE SOUTHEASTERN SEABOARD TUESDAY...THEN SLOWLY TRACKS NORTHEAST AS IT STRENGTHENS...REACHING THE CANADIAN MARITIMES BY THURSDAY. A TROUGH OF LOW PRESSURE THEN LINGERS NEAR THE AREA INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A SHORTWAVE RIDGE EXITS THIS MORNING...LEAVING ZONAL FLOW IN ITS WAKE ALOFT. WITH NO DISCERNIBLE FORCING EMBEDDED IN THE ZONAL FLOW...IT SHOULD BE DRY. THERE WILL BE SOME INCREASE IN CLOUD COVER...ESPECIALLY ACROSS NORTHERN ZONES THIS AFTERNOON IN RESPONSE TO AN APPROACHING NORTHERN STREAM SHORTWAVE. FOR HIGHS TODAY...USED A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 950 HPA PER BUFKIT SOUNDINGS. HIGHS SHOULD BE NOT QUITE AS COLD AS YESTERDAY...BUT STILL AROUND 10 DEGREES BELOW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... A WEAK SHORTWAVE PASSES TO THE NORTH TONIGHT. THIS SHOULD BRING AN INCREASE IN CLOUD COVER AND...WHEN COUPLED WITH SOME WEAK ISENTROPIC LIFT...A SLIGHT CHANCE TO CHANCE OF SOME LIGHT RAIN OR FREEZING RAIN ACROSS MAINLY THE NORTHERN 1/2 OF THE CWA. FOR NOW IT APPEARS THAT LOWS ACROSS MAINLY THE FAR NORTHERN TIER OF THE CWA...AS WELL AS THE W 2/3-3/4 OF ORANGE COUNTY SHOULD BE AT OR JUST BELOW FREEZING. SO THERE IS THE POTENTIAL FOR FREEZING RAIN IN THESE AREAS...IF ANY PRECIPITATION FALLS. AT THIS TIME...THE CONFIDENCE IN PRECIPITATION OCCURRING IS FAR TO LOW - LESS THAN 40 PERCENT TO WARRANT AN ADVISORY - OR EVEN A SPECIAL WEATHER STATEMENT HIGHLIGHTING THE POTENTIAL FOR SOME GLAZING OF ICE FROM ORANGE COUNTY ON E ACROSS INTERIOR S CT. FOR LOWS TONIGHT A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES WAS USED...WITH VALUES EXPECTED TO BE NEAR NORMAL. DEEP LAYERED RIDGING TRANSITS THE AREA SUNDAY...KEEPING THINGS DRY. AS THE RIDGE EXITS TO THE NORTHEAST SUNDAY NIGHT...DEEPENING SE SFC-SW FLOW ALOFT WILL ADVECTING IN ABUNDANT MOISTURE...AND WITH DIFFLUENT FLOW DEVELOPING ALOFT - THE LIKELIHOOD OF MODERATE RAINFALL BY LATE SUNDAY NIGHT. HAVE INCREASED POPS TO CATEGORICAL SUNDAY NIGHT. FOR HIGHS SUNDAY A BLEND OF MAV/MET/ECS GUIDANCE WITH A MIX DOWN FROM 975 HPA PER BUFKIT SOUNDINGS...AND NAM 2-METER TEMPERATURES WAS USED. HIGHS SHOULD BE A FEW DEGREES ABOVE NORMAL. FOR LOWS SUNDAY NIGHT A BLEND OF MAV/MET GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED...WITH VALUES FORECAST TO BE 10-15 DEGREES ABOVE NORMAL. LIKELY WILL SEE RISING TEMPERATURES SUNDAY NIGHT...ESPECIALLY OVERNIGHT IN RESPONSE TO LOW LEVEL WARM ADVECTION AHEAD OF THE WARM FRONT. RAIN SHOULD TAPER OFF TO SHOWERS MONDAY MORNING AS THE SURFACE AND 850 WARM FRONTS FINISH LIFTING TO THE NORTH...WITH ANY LINGERING SHOWERS COMING TO AN END MONDAY EVENING AS A COLD FRONT MOVES ACROSS THE AREA. REFER TO THE HYDROLOGY SECTION OF THE AFD FOR FORECAST RAINFALL AMOUNTS AND ANY IMPACTS. MONDAY WILL END UP BEING VERY MILD...WITH HIGHS RANGING FROM THE LOWER 60S OVER FAR EASTERN PARTS OF THE CWA...TO THE UPPER 60S TO AROUND 70 ACROSS THE NYC METRO. THIS IS 15-20 DEGREES ABOVE NORMAL AND CONSISTENT WITH A BLEND OF MIXING DOWN FROM 950-925 HPA PER BUFKIT SOUNDINGS...NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE. RECORD HIGHS ARE POSSIBLE ON MONDAY AS A RESULT. REFER TO THE CLIMATE SECTION OF THE AFD FOR DETAILS. FOR LOWS MONDAY NIGHT A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WAS USED WITH NAM 2-METER TEMPERATURES. VALUES SHOULD BE AROUND && .LONG TERM /TUESDAY THROUGH FRIDAY/... THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE MODELS HANDLING OF A FULL LATITUDE TROUGH STRETCHING FROM THE GREAT LAKES TO TEXAS TUESDAY MORNING...AND MORE IMPORTANTLY HOW A NORTHERN STREAM SHORTWAVE DIVING DOWN FROM N CENTRAL CANADA INTERACTS WITH THIS TROUGH IN THE MIDDLE OF THE WEEK. THE 00Z ECMWF IS THE STRONGEST WITH THIS NORTHERN STREAM SHORTWAVE...AND HENCE ULTIMATELY DEEPER AND CLOSER TO THE COAST WITH THE ASSOCIATED SURFACE LOW. THE CMC IS THE SLOWEST WITH THIS FEATURE AND DOES NOT HAVE MUCH IF ANY PHASING WITH THE FULL LATITUDE TROUGH...SO ITS LOW IS WEAKER AND FAR ENOUGH OUT TO SEA THAT THERE WOULD BE LITTLE OR NO IMPACT. THE GFS HAS ABOUT THE SAME STRENGTH OF THE NORTHERN STREAM SHORTWAVE AS THE CMC...BUT IS FASTER AND HENCE HAS ENOUGH PHASING WITH THE FULL LATITUDE TROUGH TO HAVE ITS LOW BE A BIT STRONGER AND CLOSER TO THE COAST THAN THE CMC. THE GEFS MEAN IS IN FAIRLY GOOD AGREEMENT WITH THE OPERATIONAL GFS. SO BASED ON THIS...FOR NOW IT APPEARS THE ECMWF IS AN OUTLIER AND HAVE LEANED MORE TOWARDS A NON-ECMWF SOLUTION AT THIS TIME. GIVEN THE GFS TENDENCY TO BE A BIT TO FAR OFFSHORE THIS FAR OUT IN TIME WITH THESE SORTS OF SYSTEMS...HAVE OPTED FOR A SOLUTION SIMILAR IN STRENGTH TO THE GFS...BUT SLIGHTLY CLOSER TO THE COAST...BUT STILL TO THE EAST OF THE 40N/70W BENCHMARK. ADJUSTED POPS TO BE FAIRLY SIMILAR TO 00Z GFS ENSEMBLE MEAN 6 HOURLY PROBABILITY OF 0.05 INCHES OF QPF FROM TUESDAY- THURSDAY...THOUGH DID GENERALLY CAP AT AROUND 40 PERCENT DUE TO UNCERTAINTY. IT SHOULD BE DRY TUESDAY UNDER SW FLOW ALOFT. A REINFORCING SHOT OF LOW LEVEL COLD AIR ARRIVES LATE TUESDAY BEHIND A PASSING DRY COLD FRONT. EXPECT PRECIPITATION TO DEVELOP FROM SE TO NW LATE TUESDAY NIGHT/WEDNESDAY MORNING AND CONTINUE...FOR NOW OFF AND ON IN NATURE...INTO WEDNESDAY EVENING...THEN TAPER OFF FROM NW TO SE INTO THURSDAY MORNING. PRECIPITATION SHOULD BEGIN AS LIGHT SNOW EARLY WEDNESDAY MORNING ACROSS AREAS N/W OF NYC...IF IT GETS THAT FAR INLAND...AND AS A RAIN/SNOW MIX ACROSS MOST OF S CT...WITH MAINLY RAIN ELSEWHERE. ALL PRECIPITATION SHOULD CHANGE TO RAIN DURING THE DAY ON WEDNESDAY. AS THE LOW DEEPENS AS IT PASSES TO OUR SE AND E WEDNESDAY NIGHT...ENOUGH LOW LEVEL COLD AIR SHOULD MOVE IN TO TURN ALL PRECIPITATION OVER TO A LIGHT SNOW. PRECIPITATION SHOULD TRANSITION BACK OVER TO RAIN THEN RAIN SHOWERS THURSDAY AS THE STORM PULLS AWAY. ONCE AGAIN...THERE IS STILL THE POTENTIAL THAT THE STORM STAYS FAR ENOUGH OUT TO SEE THAT THE AREA RECEIVES NO PRECIPITATION. THERE IS ALSO THE POSSIBILITY THAT A SOLUTION CLOSER TO THE ECMWF OCCURS...THIS WOULD RESULT IN MORE PRECIPITATION...AND LIKELY MORE SNOW...ESPECIALLY ACROSS INTERIOR PORTIONS OF THE CWA. AT THIS TIME IT IS TOO EARLY TO SPECULATE ON ANY EXACT IMPACT/EXTENT OF THIS SYSTEM DUE TO THE LARGE DEGREE OF UNCERTAINTY ON ITS EXACT TRACK AND STRENGTH. STAY TUNED. MODELS ARE STILL DIVERGENT OVER WHAT HAPPENS BEHIND THE STORM...BUT IT APPEARS MOST LIKELY THAT THERE COULD BE SOME UNSETTLED WEATHER IN ITS WAKE EITHER DUE TO A LINGERING TROUGH BEHIND THE LOW...OR ANOTHER WEAK STORM SYSTEM CROSSING THE AREA LATE IN THE WEEK. FOR TEMPERATURES TUESDAY-FRIDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE. BLENDED IN GFS 2-METER TEMPERATURES TUESDAY NIGHT-WEDNESDAY NIGHT AND ECMWF AND GFS 2-METER TEMPERATURES ON THURSDAY TO BETTER REFLECT IMPACT OF EVAPORATIVE COOLING. TEMPERATURES WILL BE BELOW NORMAL THROUGH THE LONG RANGE. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE PASSES TO THE SOUTH TODAY. VFR THROUGH THE TAF PERIOD. SOME MID AND HIGH LEVEL CLOUDS THROUGH THIS MORNING...WITH A MID LEVEL DECK MOVING IN LATE AFT/EVE. BRIEF MVFR CIG POSSIBLE 00Z TO 03Z SUN AT KSWF. WSW WINDS AT LESS THAN 8 KT THRU EARLY MORNING...THEN BACKING SLIGHTLY AND INCREASING TO 10 TO 15 KT WITH G20KT AFTER 14-15Z. GUSTS LOST BY 00Z SUN. .OUTLOOK FOR 06Z SUN THROUGH WED... .SUN...VFR. .SUN NIGHT-MON...BECOMING MVFR/IFR. POSSIBLY SUB-IFR. RA AND FG WITH LLWS POSSIBLE. .MON NIGHT-TUE...VFR. .WED...MAINLY VFR...ALTHOUGH POSSIBLE RAIN OR A RAIN/SNOW MIX MAY IMPACT THE AREA...ESPECIALLY EAST OF NYC METRO. && .MARINE... HIGH PRESSURE PASSES TO OUR SOUTH TODAY WITH THE GRADIENT TIGHTENING THIS AFTERNOON. SCA CONDITIONS BECOME LIKELY THIS AFTERNOON FOR ALL WATERS EXCEPT THE WESTERN SOUND AND NY HARBOR...BUT A GUST OR TWO UP TO 25 KT FOR THESE ZONES IS NOT OUT OF THE QUESTION. THE GRADIENT RELAXES TOWARDS SUNDAY AFTERNOON AS THE SURFACE RIDGE PIVOTS THROUGH THE WATERS. WILL CARRY THE SCA THROUGH MIDNIGHT FOR THE EASTERN SOUND AND LI BAYS...AND THROUGH THE ENTIRE NIGHT FOR THE OCEAN WATERS WEST OF FIRE ISLAND INLET. EAST OF THIS...SEAS WILL BE SLOWER TO SUBSIDE ON A SW FLOW. WAVEWATCH LOOKS A LITTLE TOO HIGH FOR SEAS HERE CONSIDERING THERE SHOULD BE VERY LITTLE SWELL TO FACTOR IN. HAVE THEREFORE ENDED SCA HERE AT NOON ON SUNDAY. WINDS PICK UP AGAIN SUNDAY NIGHT INTO MONDAY AS A STRONG LOW MOVES THROUGH THE GREAT LAKES REGION. A 60KT+ LOW LEVEL JET SHIFTING THROUGH LATE AT NIGHT INTO MONDAY MORNING BRINGS THE THREAT OF GALES. BETTER OVERALL CHANCES WOULD BE ON THE OCEAN WATERS...BUT THIS COULD EXPAND TO THE OTHER ZONES. SCA CONDITIONS OTHERWISE PREVAIL MONDAY NIGHT THROUGH TUESDAY EVENING...FOLLOWED BY A RELATIVELY BRIEF PERIOD OF SUB-SCA CONDITIONS THROUGH WEDNESDAY MORNING. SCA CONDITIONS THEN BECOME MORE PROBABLE AS WEDNESDAY PROGRESSES AS A COASTAL STORM APPROACHES FROM THE SOUTH. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH MONDAY. THERE IS THE POTENTIAL FOR 3/4 TO 1 1/3 INCHES OF RAIN FROM SUNDAY NIGHT INTO MONDAY EVENING...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. THE HEAVIEST RAINFALL AT THIS TIME IS EXPECTED OVER THE NYC METRO AREA...AND LIGHTEST AMOUNTS OVER FAR EASTERN PORTIONS OF SE CT AND THE TWIN FORKS OF LONG ISLAND. WHILE FOR THE MOST PART NO SIGNIFICANT HYDROLOGIC IMPACT IS EXPECTED...THERE IS A SMALL CHANCE FOR LOCALLY HEAVY RAINFALL LATE SUNDAY NIGHT. AREAS THAT EXPERIENCE THIS...IF ANY DO...COULD EXPERIENCE MINOR FLOODING OF URBAN/POOR DRAINAGE AREAS. && .CLIMATE... RECORD HIGH TEMPERATURES FOR MONDAY 24 NOVEMBER... LOCATION........RECORD/YEAR.....FORECAST HIGH NEWARK..............75/1979...........70 BRIDGEPORT..........63/1979...........64 CENTRAL PARK........73/1979...........68 LAGUARDIA AIRPORT...68/1999...........69 JFK AIRPORT.........63/2001*..........66 ISLIP...............63/2001...........66 * ALSO OCCURRED IN PREVIOUS YEARS && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT FOR ANZ330-340-345. SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EST SUNDAY FOR ANZ355. SMALL CRAFT ADVISORY FROM NOON TODAY TO NOON EST SUNDAY FOR ANZ350-353. && $$ SYNOPSIS...MALOIT NEAR TERM...MALOIT SHORT TERM...MALOIT LONG TERM...MALOIT AVIATION...JC MARINE...JC HYDROLOGY...MALOIT

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