Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 071147 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 647 AM EST SUN FEB 7 2016 .SYNOPSIS... HIGH PRESSURE SLOWLY RETREATS TO THE NORTHEAST TODAY. INTENSIFYING LOW PRESSURE ALONG THE SOUTHEAST US COAST WILL TRACK SOUTHEAST OF THE REGION TONIGHT INTO MONDAY. AN ACTIVE WINTER PATTERN WILL CONTINUE THROUGH MUCH OF NEXT WEEK AS SEVERAL WAVES OF LOW PRESSURE POSSIBLY IMPACT THE REGION. HIGH PRESSURE MAY RETURN AT THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SPLIT FLOW TODAY AS SOUTHERN STREAM TROUGH PIVOTS OFF THE SOUTHEAST COAST. VIGOROUS NORTHERN STREAM TROUGH DIGS ACROSS THE UPPER MID WEST TOWARD THE GREAT LAKES REGION. AT THE SFC...OUR AREA WILL BE SANDWICHED BETWEEN DEEP LOW MOVING OFF THE SE COAST AND ANOTHER STRONG LOW PRESSURE TRACKING ACROSS THE UPPER MID WEST. RIDGE EXTENDS BETWEEN THE TWO SYSTEMS ACROSS THE AREA. AFTER MORNING PATCHY FOG...A DRY AND MOSTLY SUNNY DAY IS EXPECTED AS TEMPS RISE INTO THE 40S...THANKS TO WAA IN SW FLOW...PER MOS AND FORECAST SOUNDING DATA. SUNSHINE COULD BE FILTERED THROUGH HIGH CLOUDS LATER IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... IN GENERAL...EXPECT INTERMITTENT LIGHT SNOW...POSSIBLY MODERATE AT TIMES...THROUGH THIS TIME FRAME BEGINNING LATE TONIGHT. EXACT DETAILS AND TIMING REMAIN UNCERTAIN...BUT DO EXPECT UNSETTLED WEATHER. DEEPENING LOW PRESSURE OVER THE WESTERN ATLANTIC AS IT TRACKS NORTHEAST...WITH NEXT VIGOROUS TROUGH DIGGING ACROSS THE GREAT LAKES REGION TOWARD THE EASTERN SEABOARD BY TUESDAY. AS THE INITIAL ATLANTIC SFC LOW DEPARTS TO THE NORTHEAST MONDAY...NEXT LOW SLOWLY MOVES ACROSS THE GREAT LAKES REGION...WITH SECOND LOW PRESSURE DEVELOPMENT SOMEWHERE OFF THE MID ATLANTIC COAST TUESDAY. THIS LOW PULLS AWAY TO THE EAST WITH NORLUN TROUGH LINGERING W/NWWD OVER THE AREA. AS FOR SENSIBLE WEATHER...DRY THROUGH THE EVENING AND INTO THE OVERNIGHT...WITH SNOW APPROACHING LONG ISLAND LATE TONIGHT. ON MONDAY...NOT SURE HOW FAR WEST THIS SNOW EXTENDS...BUT BEST CHANCE FOR ACCUMULATIONS WOULD BE ACROSS ERN LONG ISLAND...SE CT. THEN EXPECT LIGHT SNOW DEVELOPMENT LATE MONDAY...MONDAY NIGHT AS UPPER TROUGH/NEXT SFC LOW APPROACHES...RESULTING IN SUFFICIENT LIFT. INTERMITTENT SNOW IS POSSIBLE TUESDAY AS MENTIONED. A PROLONGED PERIOD OF UNSETTLED WEATHER IS LIKELY. TEMPS WILL BE SLIGHTLY ABOVE AVERAGE TONIGHT...RANGING FROM THE MID 20S INLAND TO THE MID 30S IN AND AROUND NYC. WITH CLOUDS AND POSSIBLE SNOW MOVING IN MONDAY...TEMPS WILL STRUGGLE TO RISE MUCH...EXCEPT NW ZONES WHERE DRIER AIR IS MORE LIKELY TO HOLD. FOR MONDAY NIGHT AND TUESDAY...NEAR NORMAL TEMPS ARE ANTICIPATED. AS FOR SNOW AMOUNTS...NAM AND SREF STILL THE WETTER SOLUTIONS WHEN COMPARED TO GFS AND ECMWF. PER COLLAB WITH WPC AND SURROUNDING OFFICES...AGREE WITH A LIKELY SCENARIO OF A DUSTING TO COUPLE INCHES ACROSS NYC METRO AND POINTS WEST AND 2 TO 5 INCHES TOWARDS EASTERN LONG ISLAND AND SE CT MONDAY. OF COURSE AMOUNTS COULD BE HIGHER IF NAM/SREF MEAN SCENARIO PANS OUT. ADDITIONAL ACCUMS ARE POSSIBLE MONDAY NIGHT AND TUESDAY...MAINLY LIGHT AMOUNTS. HOWEVER...ANY SNOW BANDS COULD PRODUCE LOCALLY HIGHER AMOUNTS...WHICH IS NEARLY IMPOSSIBLE TO PIN POINT WHERE THEY WOULD SET UP ATTM. GFS IS THE MOST AGGRESSIVE WITH POTENTIAL MODERATE SNOW TUESDAY...WHEREAS MOST OTHER MODEL/ENSEMBLE SOLUTIONS PRODUCE MUCH LIGHTER QPF/SNOW. BELIEVE A 2 TO 6 INCH SNOWFALL IS THE MOST LIKELY SCENARIO IF YOU COMBINE THE TWO SYSTEMS...WHICH MAKES SENSE SINCE MINIMAL BREAK IN PRECIP IS EXPECTED. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... UNSETTLED WEATHER WITH TIMES OF LIGHT SNOW IS LIKELY THROUGH WEDNESDAY AS UPPER TROUGH APPROACHES...AND NORLUN TROUGH LINGERS SOMEWHERE NEAR THE AREA BEHIND ATLANTIC LOW. WEDNESDAY THROUGH THURSDAY...LOW PRESSURE MOVES NE ON WEDNESDAY...BUT ANOMALOUS TROUGH IS LIKELY TO REMAIN OVERHEAD. IN FACT...A SECOND LOW MAY DEVELOP SOUTH OF THE AREA TUE NIGHT. CANNOT RULE OUT LIGHT SNOW WEDNESDAY...BUT FOR NOW IT APPEARS BEST LIFT SHIFTS EAST OF THE AREA. UPPER TROF AXIS SHIFTS EAST THURSDAY. POPS TAPER DOWN TO CHANCE WEDNESDAY AND THEN SLIGHT CHANCE ON THURSDAY. FRIDAY THROUGH SATURDAY...AN ARCTIC COLD FRONT CROSSES THE REGION FRIDAY INTO FRIDAY NIGHT AS DEEP UPPER LOW SETS UP ACROSS SOUTHEAST CANADA. THE FRONT SHOULD MOVE THROUGH DRY AS BEST MOISTURE AXIS HAS SHIFTED OFFSHORE FROM EARLIER WEEK ACTIVITY. ARCTIC HIGH BUILDS INTO THE AREA SATURDAY. THE 12Z ECMWF HAS 850 HPA TEMPS DROPPING TO BETWEEN -22C TO -26C. FORECAST TEMPERATURES ARE BELOW NORMAL THROUGHOUT THE LONG TERM...WITH INCREASING PROBABILITY OF A SHOT OF ARCTIC AIR AND WELL BELOW NORMAL TEMPERATURES AT THE WEEK AND NEXT WEEKEND. && .AVIATION /11Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE WEAKENS OVER THE AREA TODAY. MEANWHILE...LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRACK TO THE NORTHEAST...PASSING SOUTHEAST OF LONG ISLAND ON MONDAY. VFR THROUGH 06Z OR SO...WITH MVFR THEN DEVELOPING AT ALL TERMINALS EXCEPT PERHAPS KSWF THROUGH 12Z. KGON MAY SEE LIGHT SNOW DEVELOP BETWEEN 09Z AND 12Z...BUT CHC`S AREN`T HIGH ENOUGH TO INCLUDE IN THE TAF ATTM. MODERATE TO HIGH CONFIDENCE IN WIND FORECAST...ALTHOUGH TIMING OF WINDS SHIFTING TO THE E/NE THIS AFTN MAY BE 1-2 HOURS OFF. .OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY... .MON...MVFR OR LOWER LIKELY EAST/POSSIBLE WEST IN SNOW. NE-N WINDS G20-30KT WEST AND 30-40KT EAST POSSIBLE. .MON NIGHT-TUE NIGHT...MVFR OR LOWER LIKELY IN SNOW. MIXED PCPN POSSIBLE AT COAST DURING THE DAY TUE. N-NE WINDS G15-25KT POSSIBLE MON NIGHT-TUE. .WED-THU...SUB-VFR POSSIBLE IN -SN. W-NW WINDS G20-25KT POSSIBLE WED NIGHT-THU. && .MARINE... HIGH PRES WEAKENS OVER THE AREA TODAY AS INTENSIFYING LOW PRES OFF THE SE COAST TRACKS N THEN NE PASSING SE OF LONG ISLAND ON MONDAY. NE WINDS DEVELOP AND INCREASE THIS EVENING. MODELS ARE IN GOOD AGREEMENT THAT 35 KT GUSTS ARE LIKELY ON AT LEAST PORTIONS OF THE OCEAN WATERS W OF FIRE ISLAND INLET AND EASTERN LI SOUND/BAYS...THEREFORE HAVE CONVERTED THE GALE WATCH TO A WARNING HERE. REST OF HEADLINES REMAIN UNCHANGED. GALE FORCE WINDS MAY DIMINISH ON ALL BUT THE OCEAN WATERS E OF MORICHES INLET DURING THE AFTN ON MON...BUT HAVE KEPT THE END TIME AT 23Z FOR ALL ZONES TO ALLOW FOR SOME WIGGLE ROOM. SCA WINDS MAY THEN LINGER FOR A FEW HOURS IN THE EVE...HOWEVER WINDS SHOULD COME DOWN FAIRLY QUICKLY AS THE STORM DEPARTS AND THE PRES GRADIENT RELAXES. SEAS WILL LIKELY REMAIN AOA 5 FT ON THE OCEAN WATERS THROUGH THE PERIOD AS A SERIES OF STORM SYSTEMS IMPACT THE WATERS THROUGH THE MIDDLE OF THE WEEK. SUB-ADVSY WINDS PREVAIL TUE NIGHT INTO WED...BUT THEN INCREASE AGAIN WED NIGHT AND ESPECIALLY THU WITH SCA POSSIBLE ON ALL WATERS. GUSTS ON THE OCEAN WATERS MAY EVEN REACH GALE FORCE THU AFTN AND EVE...BUT SINCE IT APPEARS MARGINAL ATTM WILL REFRAIN FROM INCLUDING IN THE HWO. && .HYDROLOGY... LOW PRESSURE PASSES WELL SOUTHEAST TONIGHT INTO MONDAY...QUICKLY FOLLOWED BY ANOTHER LOW TUESDAY THAT WILL BE CLOSER. A TROUGH LINGERS NEARBY TUE NIGHT INTO WEDNESDAY. DUE TO PROLONGED UNSETTLED PRECIP EVENT...OVERALL QPF SHOULD AVERAGE FROM A TENTH OF AN INCH TO CLOSE TO A HALF AN INCH...FROM NW TO SE. MOST IF NOT ALL OF THE PRECIPITATION THAT FALLS LIKELY TO BE IN THE FORM OF SNOW. NO HYDROLOGIC CONCERNS THROUGH THIS TIME FRAME. && .TIDES/COASTAL FLOODING... POTENTIAL FOR MINOR COASTAL IMPACTS MONDAY INTO MIDWEEK WITH A NEW MOON ON MONDAY AND A SERIES OF LOW PRESSURES AFFECTING THE REGION. AN INTENSIFYING LOW PRESSURE WILL RESULT IN NE/N WINDS INCREASING TO POTENTIALLY GALE FORCE SUNDAY NIGHT AND CONTINUING INTO MONDAY. BASED ON A TRACK OF INTENSIFYING LOW THAT SHOULD BE SE OF THE 40/70 LAT/LON BENCHMARK AND COLD AIR DAMMING SIGNATURE...WOULD EXPECT POTENTIAL FOR WINDS TO BE BACKED MORE TO THE N THAN NE. THIS WOULD FAVOR THE LOWER SURGE GUIDANCE FOR MONDAY AND MONDAY NIGHT HIGH TIDE CYCLES...WHICH WOULD KEEP IMPACTS MINOR AND LIKELY LIMITED TO THE MOST VULNERABLE LOCALES. WILL HAVE TO MONITOR. AS WE HEAD INTO TUESDAYS HIGH TIDE CYCLES...POTENTIAL EXISTS FOR WINDS TO VEER MORE TO THE NE AS ADDITIONAL WAVE/S OF LOW PRESSURE TRACK TO THE SOUTH OF THE REGION. THE SPRING ASTRONOMICAL TIDES AND MULTI-TIDAL CYCLE NATURE OF THE EVENT WILL FAVOR ADDITIONAL MINOR FLOODING...WITH POTENTIAL FOR WIDESPREAD MINOR TO MODERATE IMPACTS IN THE BACK BAY AREAS TUESDAY AND WEDNESDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY FOR ANZ335-338-345. GALE WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY FOR ANZ330-340-350-353-355. && $$ SYNOPSIS...PW NEAR TERM...PW SHORT TERM...PW LONG TERM...DS/PW AVIATION...24 MARINE...24 HYDROLOGY...PW TIDES/COASTAL FLOODING...

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