Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 301547 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1047 AM EST FRI JAN 30 2015 .SYNOPSIS... AN ARCTIC COLD FRONT WILL MOVE THROUGH THIS AFTERNOON AS LOW PRESSURE RAPIDLY DEEPENS OFF THE NEW ENGLAND COAST. HIGH PRESSURE WILL BUILD IN TONIGHT INTO SATURDAY...THEN PASS TO THE SOUTH SATURDAY NIGHT. ANOTHER COLD FRONT WILL MOVE THROUGH ON SUNDAY...AND LOW PRESSURE WILL PASS TO THE SOUTH ON MONDAY. HIGH PRESSURE WILL RETURN THROUGH MID WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OVERALL...COVERAGE OF SNOW SHOWERS AHEAD OF THE ARCTIC FRONT DISSIPATING. BEST MOISTURE AND LIFT SHIFT TO THE EAST BY EARLY AFT. TEMPS WILL HOLD STEADY THROUGH MUCH OF THE AFT IN THE UPPER 20S TO LOWER 30S. THE ARCTIC COLD FRONT WILL MOVE THROUGH DURING THE MID TO LATE AFT. NW WINDS WILL ALSO INCREASE AFTER FRONTAL PASSAGE AND START TO USHER IN MUCH COLDER AIR. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... MULTIPLE WIND/COLD HAZARDS WILL EXIST DURING THIS TIME FRAME. FIRST...THE HIGHER ELEVATIONS AND THE NYC METRO URBAN HEAT ISLAND SHOULD BE THE FIRST AREAS TO SEE NW WINDS GUSTING AS HIGH AS 45-50 MPH TONIGHT VIA THE COMBO OF STRONG CAA AND A RAPIDLY TIGHTENING PRESSURE GRADIENT AS THE LOW TO THE EAST BOMBS OUT S OF NOVA SCOTIA INTO THE 980S. THESE STRONG WINDS SHOULD SPREAD TO THE REST OF THE AREA LATE TONIGHT. THE COMBO OF SUSTAINED WINDS 15-25 MPH...A LITTLE HIGHER THAN MOS GUIDANCE...AND TEMPERATURES FALLING THRU THE TEENS AND INTO THE SINGLE DIGITS INLAND...COLDER THAN THE COLDEST OF GFS/NAM MOS GUIDANCE LOWS BY A COUPLE OF DEG...WILL RESULT IN HAZARDOUS WIND CHILLS OF 15 TO 20 BELOW FROM LATE TONIGHT INTO SAT MORNING FOR MOST INLAND SECTIONS...AND AROUND 10 BELOW FOR NYC AND URBAN SECTIONS TO THE WEST...LONG ISLAND AND FAR SE CT. SAT SHOULD BE A VERY COLD DAY DESPITE SUNSHINE...WITH HIGHS STRUGGLING TO REACH 20 IN NYC AND LONG ISLAND...AND REMAINING IN THE TEENS ELSEWHERE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... GUSTY NW WINDS ABATE SATURDAY NIGHT AS DEEP LOW PRESSURE MOVES TO THE CANADIAN MARITIMES. HIGH PRESSURE BUILDS TO THE SOUTH AS A COLD FRONT APPROACHES FROM THE NW EARLY SUNDAY. ATTENTION THEN TURNS TOWARD LOW PRESSURE THAT IS EXPECTED TO DEVELOP AROUND THE MID MISSISSIPPI VALLEY AHEAD OF NORTHERN STREAM TROUGH. AT THIS TIME...MODELS HAVE SHIFTED SLIGHTLY NORTH AS THEY TRACK THE LOW FROM AROUND WEST VIRGINIA SUNDAY NIGHT TO OFF THE MID ATLANTIC COAST MONDAY MORNING. IT APPEARS THAT THE LOW TRACKS SOUTH OF THE AREA...THEN JUST SE OF THE 40N/70W BENCHMARK MONDAY AFTERNOON. STILL PLENTY OF UNCERTAINTY AS MAIN ENERGY JUST MOVING INTO WESTERN CANADA...AND RUN TO RUN SHIFTS IN TRACK HAVE BEEN OBSERVED. HOWEVER...WILL BOOST POPS INTO THE LIKELY CATEGORY FOR MUCH OF THE CWA...WITH HIGHEST POPS SOUTHERN PORTION...LOWER TO THE NORTH. ECMWF AND GFS OUTPUT AT LEAST A HALF INCH OF MEASURABLE. BASED ON THIS MODEL RUN...AGREE WITH PREVIOUS FORECAST OF A GENERAL 4 TO 8 INCHES OF SNOW IN THIS PROGRESSIVE STORM...ALTHOUGH MAY UP THAT BY AN INCH OR TWO ON THE LOW AND HIGH END...PERHAPS 5 TO 10. HOWEVER...ANY SHIFT TO THE SOUTH...WHICH IS CERTAINLY POSSIBLE...WILL RESULT IN LOWER SNOW AMOUNTS/CHANCES FOR PRECIP. THEREAFTER...ARCTIC AIR MOVES IN BEHIND THE LOW AS HIGH PRESSURE THAT ORIGINATES FROM THE CANADIAN PRAIRIES BUILDS ACROSS MID WEST AND TOWARD THE EASTERN SEABOARD BY TUESDAY. DRY WEATHER RETURNS WITH MUCH UNCERTAINTY FOR MID TO LATE WEEK. THE QUESTION IS WHETHER OR NOT SOUTHERN STREAM PHASES WITH NORTHERN STREAM TROUGH SOMETIME WED NIGHT OR THURSDAY. THIS WOULD RESULT IN CLIPPER TYPE FRONT APPROACHING FROM THE W WITH POSSIBLE LOW PRESSURE DEVELOPMENT WELL TO THE SOUTH TRACKING OFF THE EAST COAST. AGAIN...ECMWF AND GFS DIFFER WITH TIMING AND STRENGTH...SO WILL CAP POPS AT CHANCE FOR NOW LATE WED THROUGH THURSDAY. TEMPS WERE A GRIDDED MOS/MAV AND MET BLEND SAT NIGHT AND SUNDAY...WITH GRIDDED MOS AND WPC NEXT WEEK. OVERALL...COLD WEATHER WILL PREVAIL WITH BELOW OR MUCH BELOW NORMAL TEMPS ON AVERAGE. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE BUILDS IN BEHIND A DEPARTING COLD FRONT. LIGHT SNOW/SNOW SHOWERS ENDING BY NOON. SUSTAINED WINDS AND GUSTS INCREASE THROUGH THE REST OF THE DAY...FAVORING NORTH OF 310 MAG. VFR...HOWEVER MVFR/BRIEF IFR IN -SN THIS MORNING. ...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: CHC BRIEF -SN AND MVFR BEFORE 16Z. WINDS COULD BE SOUTH OF 310 AT TIMES BEFORE 16Z. KLGA FCSTER COMMENTS: CHC BRIEF -SN AND MVFR BEFORE 16Z. WINDS COULD BE SOUTH OF 310 AT TIMES BEFORE 16Z. KEWR FCSTER COMMENTS: CHC BRIEF -SN AND MVFR BEFORE 16Z. WINDS COULD BE SOUTH OF 310 AT TIMES BEFORE 16Z. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: CHC BRIEF -SN AND MVFR BEFORE 16Z. WINDS COULD BE SOUTH OF 310 AT TIMES BEFORE 16Z. KHPN FCSTER COMMENTS: TEMPO VFR POSSIBLE BEFORE 16Z. CHC MVFR LASTS THROUGH 17Z. KISP FCSTER COMMENTS: FEW W GUSTS 15-20KT POSSIBLE BEFORE 16Z. .OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY... .SATURDAY...VFR. NW WINDS 35-40 KT...DIMINISHING LATE. .SATURDAY NIGHT...VFR. NW WIND G 20-30KT POSSIBLE EARLY. .SUNDAY...VFR. NW WIND G15-20KT POSSIBLE. .SUNDAY NIGHT-MONDAY..CHANCE OF SNOW WITH IFR CONDITIONS. NE-N WIND G25-35KT POSSIBLE. .MONDAY NIGHT...BECOMING VFR FROM W TO E AS ANY SNOW COMES TO AN END. N-NW WIND G20-25KT POSSIBLE. .TUESDAY...VFR. && .MARINE... NW GALES DEVELOP ON ALL WATERS BY LATE AFTERNOON FOLLOWING AN ARCTIC COLD FROPA. GUSTS ON THE OCEAN COULD APPROACH STORM FORCE LATE TONIGHT INTO SAT MORNING. THE COMBO OF STRONG WINDS AND COLD WATER TEMPS FROM THE MID 30S TO LOWER 40S WILL ALSO RESULT IN AT LEAST MODERATE FREEZING SPRAY DURING THIS TIME FRAME. THERE IS A CHANCE FOR HEAVY FREEZING SPRAY ON LI SOUND...NY HARBOR AND THE NEAR SHORE OCEAN WATERS WHERE SST IS ONLY IN THE MID/UPPER 30S...AND A HEAVY FREEZING SPRAY WARNING MAY EVENTUALLY BE REQUIRED FOR THOSE WATERS. GUSTY WINDS WILL DIMINISH SATURDAY NIGHT INTO SUNDAY. SEAS WILL RESPOND BY SUBSIDING THROUGH THIS TIME FRAME. SOME 5-FOOTERS MAY CLIP THE EASTERNMOST OCEAN WATERS S OF MONTAUK INTO SUNDAY...BUT SUB SCA CONDITIONS ARE LIKELY ACROSS THE WATERS SUNDAY. HOWEVER...THIS WILL BE BRIEF AS WINDS INCREASE AGAIN AHEAD OF LOW PRESSURE SUNDAY NIGHT AND MONDAY. THE LOW IS EXPECTED TO PASS TO THE SOUTH MONDAY...MOVING WELL TO THE EAST MONDAY NIGHT. HIGH PRESSURE BUILDS IN TUESDAY. STRONG SCA CONDITIONS MONDAY WILL IMPROVE BY TUESDAY AS THE HIGH BUILDS. && .HYDROLOGY... LOW PRESSURE SUNDAY NIGHT AND MONDAY WILL BRING THE POTENTIAL FOR QPF OF 1/2 TO 1 INCH LIQUID EQUIVALENT...ALL IN THE FORM OF SNOW. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST SATURDAY FOR CTZ005>012. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY FOR CTZ005>007-009-010. NY...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST SATURDAY FOR NYZ067>075-078>081-176>179. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY FOR NYZ067>071. NJ...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST SATURDAY FOR NJZ002-004-006-103>108. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY FOR NJZ002-004-103-104. MARINE...FREEZING SPRAY ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY FOR ANZ330-335-338-340-345-350-353-355. GALE WARNING UNTIL 6 PM EST SATURDAY FOR ANZ330-335-338-340- 345-350-353-355. && $$ SYNOPSIS...GOODMAN/PW NEAR TERM...GOODMAN/DW/PW SHORT TERM...GOODMAN LONG TERM...PW AVIATION...MPS/NV MARINE...GOODMAN/PW/DW HYDROLOGY...GOODMAN/PW/DW

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