Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 021203 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 703 AM EST MON MAR 2 2015 .SYNOPSIS... LOW PRESSURE TRACKS INTO THE CANADIAN MARITIMES TODAY...ALLOWING HIGH PRESSURE TO QUICKLY BUILD IN TONIGHT. THE HIGH DRIFTS OVER THEN EAST OF THE REGION ON TUESDAY. LOW PRESSURE WILL TRACK WELL NORTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY...WITH A WARM FRONT LIFTING TOWARDS THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT WEDNESDAY. ANOTHER WAVE OF LOW PRESSURE MAY AFFECT THE REGION WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE WILL THEN BUILD IN FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... NW FLOW WILL BEGIN TO PICK UP TODAY AS LOW PRES DEEPENS OVER THE MARITIMES AND HIGH PRES BUILDS INTO THE OH VALLEY. DESPITE THE COLD AIRMASS...THE NW FLOW WILL ALLOW FOR DEEP MIXING. NAM AND GFS BUFR SOUNDINGS INDICATE MIXING TO ABOUT H8...WHICH YIELDS HIGHS RIGHT AROUND FREEZING INTERIOR TO JUST ABV AT THE COAST. NORMALLY...A FEW DEGREES COULD BE ADDED TO THIS WITH THE MARCH SUN ANGLE. WITH FRESH SNOW COVER THIS SHOULD BE LIMITED HOWEVER...ESPECIALLY OUTSIDE THE CITY. AS A RESULT...WENT WITH TEMPS A LITTLE BLW GUIDANCE FOR TODAY. INCREASING SUBSIDENCE BY EARLY AFTN SHOULD HELP TO ERODE THE RESIDUAL CLOUD COVER ACROSS THE AREA. A PERIOD OF CLR SKIES THIS EVE...THEN MID AND HIGH CLOUDS AHEAD OF THE NEXT SYS BEGIN TO FILTER IN LATE TNGT. TEMPS A BLEND OF GUIDANCE TNGT. WINDS THIS EVE MAY LIMIT THE INITIAL DROP OFF AFT DARK...PARTICULARLY COASTS AND CITY. AS WINDS DIMINISH OVERNIGHT...THE INCREASING MID CLOUDS ARE EXPECTED ATTM TO KEEP TEMPS FROM COMPLETELY BOTTOMING OUT. && .SHORT TERM /TUESDAY/... THE GULF BEGINS TO OPEN UP AND HI PRES OVER THE CWA DRIFTS OFFSHORE. RESULT IS INCREASING THETA-E OVER THE REGION WITH SNOW DEVELOPING FROM SW TO NE AFT 18Z. THE NAM/GFS/ECMWF ALL HAVE SIMILAR TIMING. TEMP PROFILES INDICATE THE COLUMN IS GENERALLY COLD ENOUGH FOR ALL SNOW THRU 00Z. THE NAM DOES WARM THINGS SLIGHTLY FASTER ALOFT...SO SOME SLEET MIXING IN WOULD BE POSSIBLE ACROSS STATEN ISLAND INTO NJ IN THE 22-00Z TIME PERIOD SHOULD THIS FASTER SOLN VERIFY. WITH A LOCALLY MDT BURST OF SNOW AT THE ONSET...WILL FCST AROUND AN INCH OF SNOW WRN ZONES FOR LATE IN THE AFTN. TEMPS BLW CLIMO WITH A BLEND OF GUIDANCE USED. THE ONSHORE SLY FLOW WILL KEEP TEMPS NEARLY STEADY AS THE DAY ENDS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MAIN FOCUS WILL BE PROLONGED PERIOD OF UNSETTLED WEATHER TUESDAY NIGHT THROUGH THURSDAY. MODELS IN DECENT AGREEMENT WITH A COUPLE OF NORTHERN STREAM SHORTWAVES PHASING AND DIGGING DOWN THE FRONT RANGE OF THE ROCKIES INTO NORTHERN PLAINS EARLY THIS WEEK...PHASING WITH A SW US LOW...AND THEN GRADUALLY LIFTING ACROSS THE US TO EAST COAST BY END OF THE WEEK. THE PHASED STREAMS WILL HAVE A MOIST SW FLOW FROM THE SUBTROPICAL PAC DEVELOPING ALL THE WAY INTO THE NORTHEAST US BY TUESDAY NIGHT WITH SEVERAL DISTURBANCES RIDING ALONG IT THROUGH MIDWEEK. THE FIRST PIECE OF PHASED ENERGY WILL HAVE STRONG LOW PRESSURE TRACKING FROM CENTRAL ONTARIO INTO CENTRAL QUEBEC TUE/TUES NIGHT...WITH ITS WARM FRONT...AND AN ABSORBED CENTRAL PLAINS LOW... APPROACHING THE REGION DURING THIS TIME. STRONG WAA AS DESCRIBED ABOVE WILL ALLOW FOR PCPN TO OVERSPREAD THE AREA LATE TUE AFTN AS SNOW...BUT WITH MENTIONED SUBTROPICAL PAC CONNECTION...EXPECTING TEMPS ALOFT TO WARM FAIRLY RAPIDLY TUE EVE/NIGHT WITH SNOW CHANGING TO MIXED PCPN THEN RAIN FROM S TO N. A QUICK 1 TO 2 INCHES OF SNOW CITY/COAST AND 2 TO 4 INTERIOR ARE POSSIBLE BEFORE CHANGEOVER. DUE TO THE PRIMARY LOW TRACKING WELL TO THE NW OF THE REGION...DEEP SNOW PACK AND COLD WATER TEMPS...THE SURFACE WARM FRONT WILL LIKELY HAVE TROUBLE LIFTING NORTH TUE NIGHT INTO WED. A BRIEF PERIOD OF FREEZING RAIN WITH A TRACE TO FEW HUNDREDTHS OF AN INCH OF ICE POSSIBLE ALONG THE CITY/COAST TUE EVENING BEFORE CHANGEOVER TO RAIN...BUT INTERIOR PORTIONS OF THE TRI-STATE MAY STRUGGLE TO GET ABOVE FREEZING UNTIL AFTER DAYBREAK. 1 TO 2 TENTHS OF AN INCH OF ICE POSSIBLE HERE. WITH SOME OF THE 1/2 TO 1 INCH OF PRECIP FALLING IN FROZEN FORM AND TEMPS NOT EXPECTED TO GET MUCH ABOVE THE MID TO UPPER 30S THROUGH WED MORNING...NOT EXPECTING A GREAT AMOUNT OF SNOWMELT...SO JUST EXPECTING SOME NUISANCE FLOODING ISSUES ACROSS THE COASTAL PLAIN. BEST LIFT MOVES EAST WED MORNING WITH A WEAK COLD FRONTAL PASSAGE. JUST SOME RESIDUAL SHOWER ACTIVITY IN WAKE OF FRONT. STRONGER COLD FRONT MOVES ACROSS WED EVE/NIGHT WITH FALLING TEMPS WED NIGHT. MODELS ARE SIGNALING POTENTIAL FOR ANOTHER PERIOD OF POST-FRONTAL PRECIP WED NIGHT INTO THU...WITH A SERIES OF WAVES DEVELOPING ALONG THE COLD FRONT AND AHEAD OF APPROACHING UPPER TROUGH AXIS AND THE REGION UNDER FAVORABLE ENTRANCE REGION OF A 175-200KT UPPER JET. POTENTIAL FOR MUCH OF THIS TO BE IN THE FORM OF SNOW...WITH SEVERAL INCHES POSSIBLE. HAVE TRENDED FORECAST IN THIS DIRECTION...BUT WILL HAVE TO MONITOR NEXT FEW MODELS RUNS FOR INCREASED CONFIDENCE IN SNOW THREAT. ANOTHER SHOT OF ARCTIC AIR INFILTRATES THE AREA THU INTO FRI. STRONG CANADIAN HIGH PRES THEN BUILDS TOWARDS THE AREA INTO THE WEEKEND WITH DRY WEATHER. TEMPS WILL REBOUND AROUND 5 DEGREES BELOW NORMAL NEXT WEEKEND WITH WAA DEVELOPING. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE GRADUALLY BUILDS FROM THE WEST THROUGH TUESDAY MORNING. ISOLATED MVFR EARLY TODAY BUT OVERALL VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. W WINDS 5-10 KT BECOME NW 10-20 KT WITH GUSTS 25-30 KT LATE THIS MORNING THROUGH THE AFTERNOON. WINDS AND GUSTS DIMINISH THIS EVENING. 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: MODERATE CONFIDENCE FORECAST. MVFR AND GUST TIMING COULD BE OFF 1-2 HRS FROM FORECAST. KLGA FCSTER COMMENTS: MODERATE CONFIDENCE FORECAST. GUST TIMING COULD BE OFF 1-3 HRS FROM FORECAST. KEWR FCSTER COMMENTS: MODERATE CONFIDENCE FORECAST. GUST TIMING COULD BE OFF 1-3 HRS FROM FORECAST. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: MODERATE CONFIDENCE FORECAST. GUST TIMING COULD BE OFF 1-3 HRS FROM FORECAST. KHPN FCSTER COMMENTS: MODERATE CONFIDENCE FORECAST. MVFR AND GUST TIMING COULD BE OFF 1-2 HRS FROM FORECAST. KISP FCSTER COMMENTS: MODERATE CONFIDENCE FORECAST. MVFR AND GUST TIMING COULD BE OFF 1-3 HRS FROM FORECAST. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .TUESDAY MORNING...VFR. .TUESDAY AFTERNOON...CHANCE MVFR OR LOWER IN SNOW. .TUESDAY NIGHT...IFR OR LOWER LIKELY. SNOW...CHANGING TO A WINTRY MIX LATE EVE...AND THEN RAIN AT ALL TERMINALS EXCEPT KSWF AND POSSIBLY CT TERMINALS OVERNIGHT. LLWS LIKELY. .WEDNESDAY...IFR OR LOWER POSSIBLE IN ANY RAIN - WITH A BRIEF PERIOD OF ZR POSSIBLE IN THE MORNING AT KSWF. LLWS POSSIBLE IN THE MORNING. .WEDNESDAY NIGHT-THURSDAY...MVFR OR LOWER POSSIBLE IN ANY PRECIPITATION...OTHERWISE VFR. IF THERE IS PRECIPITATION...SHOULD CHANGE TO ALL SNOW WEDNESDAY NIGHT INTO THURSDAY AND POSSIBLY CONTINUES THURSDAY AFTERNOON. NW WINDS G15-20KT POSSIBLE. .THURSDAY NIGHT-FRIDAY...VFR. NW WINDS G15-20KT POSSIBLE THURSDAY NIGHT. && .MARINE... NW WINDS WILL PICK UP TO SCA LVLS TODAY AS LOW PRES DEEPENS OVER THE N ATLC. WINDS AND SEAS WILL BEGIN TO SUBSIDE TNGT AS HI PRES QUICKLY BUILDS OVER THE WATERS. COND BLW SCA LVLS ON TUE. SCA WIND GUSTS POSSIBLE ON THE OCEAN TUE NIGHT AHEAD OF APPROACHING COLD FRONT...WITH ACCOMPANYING SCA SEAS DEVELOPING. WINDS LIKELY DROP BELOW SCA ON WED...BUT SEAS SHOULD REMAIN SCA. SCA COND COULD CONTINUE INTO THU BEHIND THE PASSAGE OF TWO COLD FRONTS...WITH A TIGHT PRES GRADIENT. SUB-ADVY CONDS FOR THE END OF THE WEEK AS THE PRES GRADIENT WEAKENS WITH ANOTHER BUILDING HIGH. && .HYDROLOGY... BETWEEN 1/2 TO 1 INCH OF LIQUID EQUIVALENT PCPN IS LIKELY LATE TUE THROUGH WED MORNING. SOME OF THIS WILL FALL AS PLAIN RAIN...THEREFORE THE COMBINATION OF THIS AND SOME MELTING SNOW PACK COULD CAUSE NUISANCE URBAN FLOODING ISSUES ACROSS THE METRO AND COASTAL PLAIN TUESDAY NIGHT INTO WEDNESDAY MORNING. BETWEEN 2 TO 4 INCHES OF LIQUID EQUIVALENT EXISTS IN THE SNOWPACK ACROSS THE AREA. WITH TEMPERATURES RISING SEVERAL DEGREES ABOVE FREEZING ON WEDNESDAY...SOME MELTING OF SNOWPACK CAN BE EXPECTED...BUT ONLY ENOUGH FOR NUISANCE FLOODING. SOME MINOR INCREASES IN STREAMFLOW ARE POSSIBLE ACROSS PRIMARILY THE NORTHEASTERN NJ RIVER BASINS DUE TO RAIN AND SNOWMELT LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. THE PROBABILITY OF ICE MOVEMENT AND ICE JAM FLOODING APPEARS LOW AT THIS TIME. ANOTHER 1/2+ INCH OF LIQUID EQUIVALENT PRECIPITATION IS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL MAINLY BE FROZEN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-335- 338-340-345. SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...JMC/NV NEAR TERM...JMC SHORT TERM...JMC LONG TERM...NV AVIATION...JM MARINE...JMC/NV HYDROLOGY...NV

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