Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 251001 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 501 AM EST SUN JAN 25 2015 .SYNOPSIS...
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A CLIPPER LOW OVER THE MID MISSISSIPPI VALLEY THIS MORNING WILL TRACK TO THE MID ATLANTIC STATES BY MONDAY MORNING...WHERE A SECONDARY COASTAL LOW WILL DEVELOP. THIS STORM WILL RAPIDLY DEEPEN AND BECOME A POWERFUL NOR`EASTER AS IT TRACKS SLOWLY NORTH TOWARD THE NEW ENGLAND COAST BY TUESDAY EVENING...AND THEN UP INTO THE CANADIAN MARITIMES BY LATE WEDNESDAY. A WEAKER SYSTEM WILL PASS THROUGH THURSDAY NIGHT INTO FRIDAY.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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THE UPPER AIR PATTERN FEATURES A BROAD UPPER TROUGH FROM THE LEE OF THE ROCKIES TO THE EAST COAST...WHICH WILL UNDERGO MAJOR AMPLIFICATION AS A DIGGING SHORT WAVE TROF OVER THE MS VALLEY CARVES OUT A FULL LATITUDE EAST COAST TROF BY MONDAY. IN THE MEANTIME...A SHORT WAVE PASSING THROUGH EASTERN CANADA TODAY WILL SEND A COLD FRONT THROUGH THE AREA THIS AFTERNOON. POLAR HIGH PRESSURE BEHIND THE FRONT OVER THE GREAT LAKES BUILDS EAST INTO THE NORTHEAST TONIGHT...LAYING DOWN THE FOUNDATION FOR COLD AIR AHEAD OF THE NEXT STORM SYSTEM. WEST WINDS WILL VEER AROUND TO THE NW THIS AFT BEHIND THE COLD FRONT WITH GUSTS UP TO 20 MPH. SOME HIGH CLOUDS WILL BEGIN TO FILTER IN LATE IN THE DAY. HIGHS WILL BE 35 TO 40...WARMEST NEAR THE COAST. STAYED CLOSE TO MET/MAV MOS.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
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HIGH PRESSURE NOSES IN FROM THE NW TONIGHT WITH CLOUDS GRADUALLY LOWERING AND THICKENING AHEAD OF A CLIPPER LOW MOVING ACROSS THE OHIO VALLEY. WARM ADVECTION AHEAD OF THE SYSTEM MAY ALLOW FOR LIGHT SNOW AND/OR FLURRIES TO WORK INTO THE AREA PRIOR TO DAYBREAK MON. THE INGREDIENTS ARE THEN COMING TOGETHER FOR A POSSIBLE HISTORIC NOR`EASTER AS A SECONDARY LOW FORMS OFF THE MID ATLANTIC EARLY MON. THIS LOW UNDERGOES RAPID INTENSIFICATION AS THE LOW CUTS OFF ALOFT NEAR THE MID ATLANTIC MON NIGHT...LIFTING SLOWLY NORTHWARD THROUGH TUE NIGHT. MSLP DROPS NEARLY 30 MB IN 24H FROM MON TO TUE MORNING...BEFORE GRADUALLY FILLING. THIS WILL PLACE THE FORECAST AREA ON THE NW FLANK OF THE LOW WITH A PROLONGED PERIOD OF MDT-HVY SNOW IN THE DEFORMATION ZONE. MOST OF THE GLOBAL MODELS AND THEIR ENSEMBLE MEMBERS MEMBERS SUPPORTS UPWARDS OF 2 INCHES LIQUID EQUIVALENT...WITH THE HIGHEST AMOUNTS ACROSS EASTERN LI/SE CT. THAT BEING THE CASE...SNOW BANDING WILL LIKELY EXTEND AS FAR WEST AS THE LOWER HUDSON VALLEY WITH SNOWFALL RATES OF 2 TO 4 INCHES AN HOUR AT TIMES. MUCH OF THE AREA SHOULD SEE A FOOT WITH AMOUNTS AS HIGH AS 2 FT POSSIBLE ACROSS EASTERN LI/SE CT. ONCE AGAIN THOUGH...THE EXACT LOCATION OF THE MOST INTENSE BANDING IS DIFFICULT TO PINPOINT AT THIS JUNCTURE. THE 00Z NAM CONTINUES TO BE AN OUTLIER ON THE EASTERN FLANK OF THE LOW TRACK AND ITS SIGNIFICANTLY LOWER PCPN HAS BEEN DISCOUNTED. IN ADDITION...THE DEEP LOW PRESSURE COMBINED WITH STRONG HIGH PRESSURE TO THE NORTH AND WEST WILL CREATE NEAR OR BLIZZARD CONDITIONS ACROSS MUCH OF THE REGION. A BLIZZARD WATCH HAS BEEN POSTED FOR LI AND MUCH OF THE SOUTHERN CT...WITH A WINTER STORM WATCH ELSEWHERE. POTENTIAL EXISTS FOR GUST OF 35 TO 50 MPH...HIGHEST TO THE EAST. LIGHT SNOW DEVELOPS MON MORNING AND THEN GRADUALLY PICKS UP IN THE LATE AFT. MDT-HVY SNOW WILL FALL FOR MUCH OF MON NIGHT INTO TUE BEFORE TAPERING OFF TUE EVENING. TEMPS DURING THE STORM WILL GENERALLY BE IN THE 20S WITH WIND CHILLS IN THE SINGLE DIGITS TO MID TEENS.
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&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/...
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BEHIND THE STORM...DRY WEATHER WEDNESDAY AND THURSDAY...THEN A WEAKER LOW AFFECTS US THURSDAY NIGHT INTO FRIDAY. CAPPED POPS A CHANCE FOR SNOW...WITH PRECIPITATION MORE LIKELY TO BE SNOW...BUT MIXED PRECIPITATION NOT OUT OF THE QUESTION.
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&& .AVIATION /09Z SUNDAY THROUGH THURSDAY/...
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** HIGH IMPACT SNOW AND WIND EVENT PROBABLE LATE MONDAY INTO TUESDAY NIGHT...SEE OUTLOOK FOR DETAILS ** A COLD FRONT CROSSES THE AREA TODAY. HIGH PRESSURE BUILDS DOWN FROM SOUTHEASTERN CANADA THIS EVENING. VFR THROUGH THE TAF PERIOD...EXCEPT BRIEF PERIOD OF MVFR AT KSWF THROUGH 11Z. CEILINGS FALL TO AROUND 5000 FT TOWARDS THE END OF THE TAF PERIOD. WINDS ARE MAINLY WNW AROUND 10-15KT. WNW-NW WINDS G15-20KT BY LATE THIS MORNING. GUSTS WILL ABATE BY LATE AFTERNOON. WINDS VEER TO THE N AT CITY TERMINALS BY MID-LATE EVENING AT AROUND 10 KT...AND BECOME LIGHT AND VARIABLE ELSEWHERE. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .MONDAY MORNING...MVFR POSSIBLE IN -SN. E-ENE WINDS G20-25KT PROBABLE. .MONDAY AFTERNOON-TUESDAY NIGHT...IFR/LIFR CONDITIONS LIKELY IN SNOW. BLIZZARD CONDITIONS POSSIBLE W/PROBABLE E WITH POTENTIAL FOR HEAVY SNOW AND NE-N WINDS G35-50 KT. .WEDNESDAY...VFR. NW WINDS G25-35KT POSSIBLE. .WEDNESDAY NIGHT-THURSDAY...VFR.
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&& .MARINE...
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SCA CONDITIONS WILL PERSIST ACROSS MOST WATERS THROUGH SUN AFT. WINDS AND SEAS WILL FALL BELOW SCA THIS EVENING. WINDS AND SEAS INCREASE MONDAY MORNING INTO MONDAY AFTERNOON AHEAD OF A STRONG STORM THAT WILL DEVELOP ALONG THE MIDDLE ATLANTIC COAST. THE STORM WILL PASS TO THE EAST OF THE WATERS TUESDAY...AND THEN NORTHEAST TUESDAY NIGHT INTO WEDNESDAY. HAVE ISSUED A GALE WATCH FOR NY HARBOR...SOUTH SHORE BAYS....AND WESTERN LONG ISLAND SOUND AND A STORM WATCH FOR ALL OCEAN WATERS...EASTERN LONG ISLAND SOUND...AND PECONIC AND GARDNERS BAYS. STRONGEST WINDS AND HIGHEST SEAS WILL OCCUR MONDAY NIGHT INTO TUESDAY AFTERNOON AS THE STORM PASSES. USED WAVEWATCH AS A STARTING POINT FOR WAVES...BUT INCREASED BY SEVERAL FEET IN COORDINATION WITH SURROUNDING OFFICES. POTENTIAL EXISTS FOR A FEW GUSTS OVER EASTER OCEAN WATERS AND EASTERN SOUND TO APPROACH 60 KT. WINDS AND SEAS THEN DIMINISH WEDS AND THURS AS THE STORM MOVES NE AND HIGH PRESSURE APPROACHES FROM THE WEST.
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&& && .HYDROLOGY...
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POTENTIAL FOR A MAJOR SNOWSTORM MONDAY INTO TUE WITH LIQUID EQUIVALENT AMOUNTS OF 1 TO 2 INCHES. PRECIPITATION TYPE HOWEVER DOES APPEAR TO BE MOSTLY ALL SNOW...REDUCING ADVERSE HYDROLOGIC IMPACTS DURING THE STORM. THERE IS STILL UNCERTAINTY WITH THESE AMOUNTS. ICE ON THE WALLKILL AND YANTIC RIVERS IS CAUSING MINOR FLUCTUATIONS IN RIVER LEVELS AT THIS TIME.
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&& .TIDES/COASTAL FLOODING... A POTENTIAL INTENSE COASTAL STORM COULD BRING MINOR TO LOCALLY MODERATE COASTAL IMPACTS TO THE REGION MONDAY NIGHT INTO TUESDAY MORNING. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...BLIZZARD WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR CTZ006>008-010>012. WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR CTZ005-009. NY...BLIZZARD WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR NYZ078>081-177-179. WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR NYZ067>075-176-178. NJ...WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR NJZ002-004-006-103>108. MARINE...GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON FOR ANZ335-338-345. SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ330- 335-338-340-345-350-353-355. STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON FOR ANZ330-340-350-353-355.
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&& $$ SYNOPSIS...DW NEAR TERM...DW SHORT TERM...DW LONG TERM...JC/DW AVIATION...DS MARINE...DS HYDROLOGY...JC/DW TIDES/COASTAL FLOODING...NV/DW

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