Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 231804 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 104 PM EST TUE DEC 23 2014 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE TRACKS JUST TO THE SOUTH AND EAST OF LONG ISLAND THROUGH TONIGHT. A STRONGER STORM SYSTEM WILL IMPACT THE REGION CHRISTMAS EVE THROUGH CHRISTMAS MORNING. A COLD FRONT WILL MOVE ACROSS THE REGION CHRISTMAS DAY. HIGH PRESSURE BUILDS TO THE SOUTH THURSDAY NIGHT THROUGH SATURDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST SATURDAY NIGHT...THEN PUSHES TO THE SOUTH SUNDAY. THIS FRONT THEN STALLS OUT SOUTH OF THE AREA...WITH WAVES OF LOW PRESSURE RIDING ALONG IT INTO EARLY NEXT WEEK...AS CANADIAN HIGH PRESSURE BUILDS IN TO THE NORTH. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SCATTERED SHOWER ACTIVITY WILL CONTINUE TO PUSH NE THROUGH CT/LI WITH ISOLATED RAIN SHOWERS AND DRIZZLE THIS AFTERNOON. HIGH TEMPS GENERALLY IN THE 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... LOW PRES PASSES OVER MONTAUK POINT THIS EVENING. WILL KEEP CHANCE POPS IN THE FORECAST FOR THIS EVENING AS THERE WILL BE WEAK LIFT ALONG WITH ABUNDANT LOW LEVEL MOISTURE...AND NOT EXPECTING WIDESPREAD RAINFALL UNTIL LATER TONIGHT. DEEP UPPER TROUGH AND SFC LOW PRES DIGS INTO THE MIDWEST. SEVERAL SHORTWAVES AHEAD OF THE MAIN SYSTEM WILL ENHANCE RAINFALL OVER THE REGION BY WEDNESDAY MORNING. THE MAIN LOW TRACKS TO THE NORTH INTO CANADA AS AN OPEN WAVE DEVELOPS OVER THE SOUTHEAST U.S. THAT WAVE MOVES ALONG THE COAST ON CHRISTMAS EVE AND MOVES ACROSS THE REGION WEDNESDAY NIGHT. 50-60 KT LOW LEVEL JET WILL MOVE INTO THE REGION IN THE AFTERNOON AND AT NIGHT...AND PRECIPITABLE WATERS ACROSS THE REGION WILL RANGE FROM 1.5-2"...WHICH IS EXCEEDINGLY HIGH FOR THIS TIME OF YEAR. MODERATE TO HEAVY RAIN EXPECTED WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WITH ML MOST UNSTABLE CAPE OF 200-300 J/KG ACROSS SOUTHERN ZONES...WILL ADD ISOLATED THUNDERSTORMS IN THE FORECAST FOR WEDNESDAY AFTERNOON. RAIN GRADUALLY TAPERS OFF FROM WEST TO EAST CHRISTMAS MORNING AS COLD FRONT MOVES ACROSS THE REGION. PRES GRADIENT TIGHTENS CHRISTMAS AFTERNOON...AND STRONG WESTERLY WINDS WILL DEVELOP...RANGING FROM 15-20 MPH WITH 25-35 MPH GUSTS. THE DIURNAL RANGE THROUGH THE PERIOD WILL GENERALLY RANGE FROM THE 40S AT NIGHT TO THE 50S DURING THE DAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... DEEP LAYERED RIDGING BEGINS TO PUSH OUTER PERIPHERY OF CLOSED LOW OVER THE CANADIAN MARITIMES TO THE NE THURSDAY NIGHT...ALLOWING FOR CONTINUED CLEARING...ESPECIALLY OVER EASTERN ZONES. LOWS THURSDAY NIGHT WERE BASED ON A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METER TEMPERATURES...WITH VALUES 5-10 DEGREES ABOVE NORMAL. DEEP LAYERED RIDGING BUILDS OVER THE AREA FRIDAY...WITH ITS AXIS PASSING TO THE EAST FRIDAY NIGHT...FOLLOWED BY SW FLOW ALOFT ON SATURDAY. SHOULD BE SUFFICIENT SUBSIDENCE WITH/IN THE VICINITY OF THE RIDGE TO KEEP THINGS DRY WITH MINIMAL CLOUD COVER IN THIS TIME FRAME AS A RESULT. THE GFS IS AN OUTLIER COMPARED TO THE ECMWF/CMC/ITS ENSEMBLE MEAN WITH HOW PROGRESSIVE IT IS WITH THE COLD FRONTAL PASSAGE FOR THE LATTER HALF OF THE WEEKEND...AND ALSO HOW FAR OFFSHORE THE FRONT STALLS OUT. AS A RESULT...BASED FORECAST SATURDAY NIGHT-MONDAY ON A BLEND OF THE ECMWF/CMC/GEFS MEAN. BASED ON THIS BLEND...SATURDAY NIGHT SHOULD BE DRY WITH NO SIGNIFICANT FORCING PROGGED...THEN HAVE A CHANCE FOR SOME -SHRA ACROSS SOUTHERN ZONES AND SOME -SHRA/-SHSN ACROSS NORTHERN ZONES WITH THE COLD FRONTAL PASSAGE SUNDAY. FOR NOW GOING WITH CHANCE POPS SUNDAY NIGHT AND SLIGHT CHANCE POPS MONDAY TO REFLECT POTENTIAL WAVES OF LOW PRESSURE PASSING TO THE S...WITH MAINLY SNOW EXPECTED ACROSS N ZONES...AND RAIN CHANGING TO SNOW ACROSS S ZONES. STILL QUITE A BIT OF UNCERTAINTY ON EXACT TIMING/STRENGTH/TRACK AND NUMBER OF THESE WAVES. FOR NOW BEST TO CHARACTERIZE WEATHER FOR EARLY NEXT WEEK AS POTENTIALLY UNSETTLED...WITH A BETTER CHANCE FOR SNOW THAN RAIN AT MOST LOCATIONS...IF ANY THING FALLS AT ALL. GIVEN LARGE DEGREE OF UNCERTAINTY...IT IS TO EARLY TO SPECULATE ON WHAT...IF ANY IMPACT THERE WILL BE FROM THESE POTENTIALLY MULTIPLE COASTAL LOWS PASSING TO THE S. FOR TEMPERATURES FRIDAY-MONDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE. TEMPERATURES WILL BE WELL ABOVE NORMAL FRIDAY-SATURDAY NIGHT. IF ECMWF/CMC ARE CORRECT...COULD END UP 5 TO POSSIBLY 10 DEGREES WARMER THAN CURRENTLY FORECAST - GIVEN WELL MIXED LOW LEVELS AND 850 TEMPERATURES FORECAST OF 6 TO 8C. SUNDAY/SUNDAY NIGHT SHOULD FEATURE TEMPERATURES SLIGHTLY ABOVE NORMAL...THEN BELOW NORMAL TEMPERATURES ARE FORECAST FOR NOW ON MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... WEAK LOW PRESSURE ALONG A WARM FRONT APPROACHES...REACHING JUST SOUTH OF LONG ISLAND THIS EVENING. THE WARM FRONT MOVES NORTHWARD TOWARD THE AREA WEDNESDAY MORNING. WINDS REMAIN FROM THE NORTHEAST...OR EVEN BACK TOWARD THE N/NE AS THE DAY PROGRESSES. SPEEDS 5 TO 10 KTS. WINDS BECOME LIGHT TONIGHT...THEN TURN TOWARD THE E/SE WEDNESDAY MORNING. MAINLY IFR CONDITIONS ARE ANTICIPATED THIS AFTERNOON. CEILINGS UNDER 1 KFT AND VSBYS BETWEEN 1 AND 5 MILES. IFR OR EVEN LIFR POSSIBLE TONIGHT INTO WEDNESDAY MORNING. PLEASE SEE INDIVIDUAL TERMINAL FORECAST FOR DETAILS. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT KJFK FCSTER COMMENTS: CEILINGS REMAIN BELOW 1 KFT THIS AFTERNOON. VSBYS MAINLY 3 MILES OR ABOVE...BUT SHOULD LOWER LATER THIS AFTERNOON. KLGA FCSTER COMMENTS: CEILINGS REMAIN BELOW 1 KFT THIS AFTERNOON AND COULD REMAIN BELOW 500 FEET. VSBYS 1 TO 3 MILES. KEWR FCSTER COMMENTS: CEILINGS REMAIN BELOW 1 KFT THIS AFTERNOON AND COULD REMAIN BELOW 500 FEET. VSBYS 1 TO 3 MILES. KTEB FCSTER COMMENTS: CEILINGS REMAIN BELOW 1 KFT THIS AFTERNOON AND COULD REMAIN BELOW 500 FEET. VSBYS 2 TO 4 MILES. KHPN FCSTER COMMENTS: CEILINGS REMAIN BELOW 500 FEET. VSBYS 1 TO 3 MILES MAY LOWER BELOW 1 NM LATER THIS AFTERNOON. KISP FCSTER COMMENTS: CEILINGS REMAIN BELOW 1 KFT THIS AFTERNOON AND COULD FALL BELOW 500 FEET. VSBYS 1 TO 3 MILES. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .WED AFTERNOON...IFR IN RAIN. CHC +RA. SE-S 10-20KT. LLWS. .WED NIGHT...IFR. RA. CHC +RA. S 15-20G20-25KT. .THU...IMPROVING TO VFR IN THE MORNING. WINDS SHIFT W EARLY 20G30-35KT. CHANCE OCCASIONAL GUSTS 35-40KT. .THU NIGHT...VFR. W 15-20G30-35KT EVE...DIM 10KT LATE. .FRI...VFR. .SAT...VFR. .SUN...VFR...WITH CHANCE OF SUB VFR LATE IN THE DAY. && .MARINE... SEAS ON THE OCEAN WILL RANGE FROM 6-9 FT TODAY AND TONIGHT. WINDS CONTINUE TO SUBSIDE THIS AFTERNOON INTO EVENING...BUT SCA OCEAN SEAS WILL REMAIN SMALL CRAFT ADVISORY THROUGH TONIGHT. BY WEDNESDAY AFTERNOON...SCA LEVEL WIND GUSTS WILL DEVELOP ON ALL WATERS ALONG WITH OCEAN SEAS BUILDING TO 5-7 FT AS LOW PRES MOVES NORTH THROUGH THE WATERS. A COLD FRONT PUSHES ACROSS THE WATERS THURSDAY MORNING. GRADIENT TIGHTENS...AND GALE FORCE WINDS GUSTS ARE POSSIBLE ON THE WATERS LATE THURSDAY. GUSTS TO GALE FORCE ARE LIKELY ON THE COASTAL OCEAN WATERS AND POSSIBLE ELSEWHERE THROUGH AT LEAST THURSDAY EVENING...AND POSSIBLY THROUGH THE NIGHT OVER THE EASTERN COASTAL OCEAN WATERS. WINDS AND SEAS FALL BELOW SCA LEVELS ON ALL WATERS BY FRIDAY MORNING AND REMAIN SO THROUGH SATURDAY. SEAS COULD POSSIBLY BUILD TO SCA LEVELS ON THE COASTAL OCEAN WATERS EAST OF MORICHES INLET LATE SATURDAY. && .HYDROLOGY... ANOTHER 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS WEDNESDAY THROUGH THURSDAY MORNING...WITH TOTAL RAINFALL OF 1 1/2 TO 2 1/4 INCHES WITH LOCALLY HIGHER AMOUNTS. MINOR URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE. IT SHOULD BE DRY FROM LATE THURSDAY THROUGH AT LEAST SATURDAY EVENING. && .TIDES/COASTAL FLOODING... THREAT OF MINOR COASTAL FLOODING ENDING FOR WESTERN LI SOUND OVER THE NEXT HOUR OR SO AS TIDES HAVE PEAK AND RECEDE. LOCALIZED MINOR COASTAL FLOODING LIKELY ACROSS MAINLY THE SOUTH SHORE BAYS OF LI AND NYC WITH WED MORNING HIGH TIDE. LOW POTENTIAL FOR THIS OCCUR WITH WED NIGHT HIGH TIDE WITH STRONG SOUTHERLY WINDS...BUT 2 TO 2 1/2 FT SURGE NEEDED FOR MINOR FLOODING. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR ANZ330- 335-350-353-355. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EST WEDNESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MALOIT/MPS NEAR TERM...MALOIT/MPS/NV SHORT TERM...MPS LONG TERM...MALOIT AVIATION...PW MARINE...MALOIT/MPS/NV HYDROLOGY...MALOIT/MPS TIDES/COASTAL FLOODING...NV

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