Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 280535 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 135 AM EDT THU MAY 28 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN MOVE ACROSS THURSDAY INTO THURSDAY NIGHT. HIGH PRESSURE WILL RETURN ON FRIDAY...QUICKLY MOVING INTO THE WESTERN ATLANTIC LATE FRIDAY AFTERNOON INTO THE WEEKEND. A SLOW MOVING COLD FRONT APPROACHING FROM THE WEST WILL EVENTUALLY MOVE IN SATURDAY NIGHT AND STALL NEARBY FOR SUNDAY INTO EARLY NEXT WEEK. HIGH PRESSURE WILL BUILD IN FROM THE NORTH LATE TUESDAY INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
SHWRS AND TSTMS HAVE ENDED. REDEVELOPMENT IS EXPECTED TO HOLD OFF TIL TODAY. WITH ABUNDANT LOW LEVEL MOISTURE DUE TO THE SHOWERS/TSTMS THAT OCCURRED THIS EVENING...AND INCREASING LOW LEVEL MOISTURE DUE TO CONTINUED ONSHORE FLOW...CAN EXPECT AT LEAST PATCHY FOG TO DEVELOP. WILL INCLUDE THE PATCHY FOG FOR THE INTERIOR DUE TO THE RAINFALL AS WELL AS FOR COASTAL AREAS. LOWS TONIGHT WILL GENERALLY DROP INTO THE LOW TO MID 60S...WITH THE WARMEST TEMPS IN/AROUND NYC.
-- End Changed Discussion --
&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... MODELS DIFFER ON COVERAGE/EXTENT OF CONVECTION WITH A COLD FRONT ON THURSDAY. ALSO DIFFER ON TIMING WITH THE GFS/ECMWF FASTER THAN THE NAM/CMC-REG. NOTING 700-500 HPA FLOW HAS A FAIRLY DECENT PERPENDICULAR COMPONENT TO THE FRONT...LEANED TOWARDS THE FASTER TIMING OF THE GFS/ECMWF FOR POPS. WITH A WEAKENING FRONT THOUGH...DID NOT FEEL COMFORTABLE GOING WITH HIGHER THAN CHANCE POPS AT THIS TIME. PROBABILITIES ARE GENERALLY HIGHER FROM NYC AND AREAS JUST NORTH/WEST. WITH LESS MLCAPE...500-1000 J/KG OVER THE INTERIOR THAN TODAY...AND THE BEST DYNAMIC FORCING FORECAST TO THE N OF THE REGION...DO NOT THINK THERE IS AS MUCH OF A THREAT FOR SEVERE WEATHER. THOUGH AN ISOLATED STRONG TO SEVERE STORM OR TWO CANNOT BE COMPLETELY RULED OUT. HIGHS ON THU SHOULD BE IN THE 80S INLAND...AND IN THE 70S NEAR THE COAST...MAINLY PER WARMER NAM MOS GUIDANCE. WOULD NOT BE SURPRISING IF A FEW LOCATIONS IN NE NJ APPROACHED 90. DEWPOINTS ON THURSDAY SHOULD BE A TAD LOWER THAN TODAY...MAINLY IN THE LOWER 60S. A WEAK COLD FRONT WILL MOVE ACROSS THURSDAY NIGHT. LITTLE TO NO PRECIPITATION IS EXPECTED WITH THE FRONT. LOWS SHOULD BE IN THE 60S IN MOST PLACES...EXCEPT MID/UPPER 50S IN THE VALLEYS WELL NORTH/WEST OF NYC. THERE IS A MODERATE RISK FOR RIP CURRENTS AT OCEAN BEACHES ON THURSDAY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... RIDGING TREND RESUMES ALOFT WITH JET STREAM WELL NORTH OF THE REGION FOR FRIDAY. THIS RIDGE SHIFTS SLOWLY OFFSHORE AND BECOMES LESS AMPLIFIED AS A LONGWAVE TROUGH PUSHES EASTWARD ACROSS SOUTHERN CANADA. THE SAME PATTERN REMAINS THROUGH THE FIRST HALF OF THE WEEKEND AND THEN THE JET PUSHES FARTHER SOUTH INTO THE REGION FOR THE REST OF THE WEEKEND INTO EARLY NEXT WEEK. THE MID LEVEL RIDGE WILL BECOME MORE BROAD SUNDAY WITH A SHORTWAVE MOVING IN EARLY NEXT WEEK. THE RIDGING RESUMES BY MID NEXT WEEK WITH JET STREAM ONCE AGAIN MOVING WELL NORTH OF THE REGION. AT THE SURFACE...HIGH PRESSURE FROM THE CANADIAN MARITIMES QUICKLY SETTLES INTO THE WESTERN ATLANTIC LATE AFTERNOON FRIDAY AND INTO THE WEEKEND. THE INFLUENCE OF THE HIGH WILL LESSEN WITH TIME AS A SLOW MOVING COLD FRONT APPROACHES FROM THE WEST. THE PARENT LOW ATTACHED TO THIS FRONT WILL NOT BE THAT STRONG...SLOWLY DEEPENING WITH EASTWARD PROGRESS THROUGH SATURDAY AND THEN DEEPENS MORE WITHIN THE CANADIAN MARITIMES SUNDAY THROUGH SUNDAY NIGHT. THE COLD FRONT WILL BE MOVING WITHIN CLOSER PROXIMITY OF THE REGION THROUGH THIS TIME. THE FRONT WILL THEN STALL NEAR THE REGION WITH LOW PRESSURE AND INVERTED TROUGH DEVELOPING AT THE SURFACE TO THE SOUTHWEST OF THE REGION ALONG THE FRONT. HIGH PRESSURE RETURNS LATE TUESDAY FROM THE CANADIAN MARITIMES...BUT ONCE AGAIN BECOMES RE-ESTABLISHED QUICKLY OFFSHORE INTO THE WESTERN ATLANTIC. IN TERMS OF WEATHER...CONDITIONS REMAIN DRY FRIDAY AND FRIDAY NIGHT. HOWEVER...WITH THE MOIST SOUTHERLY FLOW FRIDAY NIGHT INTO SATURDAY MORNING...EXPECTING SOME PATCHY FOG ACROSS THE REGION...ESPECIALLY COASTAL REGIONS. SOME MODELS ARE SHOWING THIS MOISTURE AS VERY LIGHT QPF. THERE WILL BE A GRADUAL INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS FIRST NORTH AND WEST OF NYC SATURDAY AHEAD OF THE COLD FRONT. THE CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE SATURDAY NIGHT ACROSS THE WHOLE FORECAST REGION WITH SHOWERS BECOMING LIKELY SUNDAY AND SUNDAY NIGHT. THUNDERSTORMS WILL BE MORE LIMITED SUNDAY AND SUNDAY NIGHT WITH DECREASING INSTABILITY WITH A MORE NORTHERLY AND EASTERLY FLOW DEVELOPING DURING THE DAY. WITH THE FRONT STALLING NEAR THE REGION...CHANCES FOR SHOWERS REMAIN INTO EARLY NEXT WEEK...BEFORE BECOMING MORE MINIMAL TUESDAY AS THE FRONT PUSHES FARTHER SOUTH OF THE AREA WITH MAINLY DRY CONDITIONS RETURNING LATE TUESDAY NIGHT INTO NEXT WEDNESDAY. THE AIR MASS WILL STAY MOSTLY AS MARITIME TROPICAL THROUGH THE LONG TERM BUT A LITTLE COOLER FOR MONDAY AND TUESDAY NEXT WEEK. THE HIGHS ARE FORECAST TO BE AROUND OR SLIGHTLY MORE THAN 5 DEGREES ABOVE NORMAL ON AVERAGE FRIDAY AND SATURDAY...NEAR NORMAL FOR SUNDAY...AROUND 5 DEGREES BELOW NORMAL MONDAY AS WELL AS A FEW DEGREES BELOW NORMAL TUESDAY. TEMPERATURE RETURN TO NEAR NORMAL BY MID NEXT WEEK. LOWS AT NIGHT OVERALL ARE FORECAST TO BE NEAR TO ABOVE NORMAL. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
HIGH PRESSURE REMAINS ACROSS THE NORTH ATLANTIC. MEANWHILE...AN AREA OF LOW PRESSURE WILL MOVE THROUGH EASTERN CANADA OVERNIGHT THROUGH THURSDAY BRINGING A WEAKENING COLD FRONT TOWARD THE AREA THURSDAY AFTERNOON. THE FRONT IS EXPECTED TO CROSS THE LOWER HUDSON VALLEY DURING THE LATE AFTERNOON/EVENING...AND MOVE THROUGH THE NYC AREA TERMINALS SHORTLY AFTER 00Z FRIDAY. THERE IS A LOW CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS WITH THE FRONT. VFR UNTIL LATE TONIGHT WHEN MARGINAL CEILINGS IN STRATUS ARE EXPECTED WITH CEILINGS 1000 TO 2000 FT. LOCAL MARGINAL VFR FOG IS ALSO POSSIBLE. ANY MARGINAL VFR CEILINGS BECOME VFR AFTER 15Z THURSDAY. MODERATE CONFIDENCE IN THE FORECAST OF STRATUS AND FOG. .OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY... .THU NIGHT...COLD FRONT MOVES THROUGH EARLY IN THE EVENING WITH THE WIND SHIFTING TO NW TO N. VFR. .FRI...VFR. LGT NE WINDS VEERING THRU THE DAY. .SAT...MRNG MVFR OR LOWER POSSIBLE. CHC SHWRS AND TSTMS IN THE AFTN AND OVERNIGHT WITH MVFR OR LOWER. STRONG SLY FLOW. .SUN...MVFR OR LOWER IN SHOWERS/TSTMS POSSIBLE. SHIFTING WINDS TO THE E/NE. .MON...POSSIBLE IMPROVEMENT TO VFR IF SHOWERS/TSTMS MOVE TO THE SOUTH. E/NE FLOW.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
WINDS ON THE OCEAN WILL DIMINISH TO 10-15 KT WITH GUSTS UP TO 20 KT...AND TO 5-10 KT ON ALL OTHER WATERS. OCEAN SEAS WILL CONTINUE TO BUILD TO 5 FT...AND WILL REMAIN ABOVE 5 FT THROUGH THURSDAY MORNING. WILL EXTEND THE SCA ON THE OCEAN WATERS THROUGH 11 AM THURSDAY. OCNL GUSTS TO 25 KT POSSIBLE IN THE AFTERNOON ON THE OCEAN WATERS...BUT MOST GUSTS WILL BE AROUND 20 KT. COLD FRONT MOVES ACROSS THE WATERS LATE THURSDAY/THURSDAY NIGHT. CONDS FALL BELOW SCA CRITERIA. PERSISTENT SOUTHERLY FETCH COULD BUILD SEAS ON THE OCEAN TO 5 FT SATURDAY...AND REMAIN THERE FOR THE REST OF THE FCST PERIOD...EVEN AS WINDS SWITCH TO MORE EASTERLY SUNDAY INTO EARLY NEXT WEEK.
-- End Changed Discussion --
&& .HYDROLOGY... ON THURSDAY...THERE IS THE POTENTIAL FOR LESS THAN 1/4 OF AN INCH OF BASIN AVERAGE RAINFALL. HOWEVER...WITH STORM MOTION OF AROUND 10 KT AND PRECIP EFFICIENCY NEAR 1.25 INCHES...THERE IS STILL POTENTIAL FOR SLOW MOVING STORMS PRODUCING LOCALLY MODERATE TO HEAVY RAINFALL...ESPECIALLY OVER SOUTHERN CT. THIS COULD RESULT IN THE MINOR FLOODING OF URBAN/POOR DRAINAGE AREAS...ESPECIALLY IF IT OCCURS OVER AREAS RECEIVING LOCALLY HEAVY RAINFALL TODAY. THERE IS POTENTIAL FOR HEAVY RAIN SUNDAY AND SUNDAY NIGHT WITH PW FORECAST TO REACH UP TO NEAR 1.75 INCHES. THERE WILL BE POTENTIAL AS WELL FOR AN EXTENDED WIDESPREAD RAINFALL LATE THIS WEEKEND INTO EARLY NEXT WEEK WITH A COLD FRONT STALLING NEARBY. && .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350- 353-355.
-- End Changed Discussion --
&& $$ SYNOPSIS...GOODMAN NEAR TERM...MPS/JMC SHORT TERM...GOODMAN LONG TERM...JM AVIATION...BC MARINE...MPS HYDROLOGY...GOODMAN/JM

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.