Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 172057 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 357 PM EST WED DEC 17 2014 .SYNOPSIS... HIGH PRESSURE WILL PASS TO THE NORTH AND EAST OF THE AREA THROUGH THE WEEKEND...WHILE WEAK LOW PRESSURE OVER THE NORTHERN GULF COAST EMERGES ALONG THE SOUTHEAST COAST ON SUNDAY. THIS LOW WILL TRACK SLOWLY NORTH AND EAST MONDAY INTO TUESDAY...PASSING SOUTH OF THE AREA TUESDAY MORNING. MEANWHILE...THERE IS THE POTENTIAL FOR A STRONG STORM SYSTEM TO IMPACT THE AREA LATE TUESDAY NIGHT INTO WEDNESDAY AS DEEPENING LOW PRESSURE TRACKS UP INTO THE OHIO VALLEY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A SHORTWAVE ALOFT PASSES THROUGH. MOISTURE IS LIMITED...BUT ENOUGH FOR A MENTION OF ISOLATED SPRINKLES...AND POSSIBLY MIXED WITH FLURRIES ACROSS SOME OF THE NORTHERN ZONES AS MOISTURE COULD EXTEND JUST DEEP ENOUGH FOR ICE CRYSTALS TO FORM. LOW TEMPERATURES WILL BE ABOVE NORMALS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/... HIGH PRESSURE CONTINUES TO BUILD IN THROUGH THE PERIOD. A TIGHT PRESSURE GRADIENT WILL RESULT IN A BREEZY DAY FOR THURSDAY. WENT WITH THE WARMER MAV MOS FOR HIGH TEMPS BASED ON MIXING TO 900MB AND A MODERATE DOWNSLOPE FLOW COMPONENT. OVERNIGHT LOWS THURS NIGHT IS AN EVEN BLEND OF NAM AND MAV MOS. DRY WEATHER CONTINUES FOR FRIDAY WITH LIGHTER WINDS. THE WARMER MAV MOS ONCE AGAIN WAS USED FOR HIGH TEMPS BASED ON TEMPS ALOFT. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... GLOBAL MODELS...IN PARTICULAR THE 12Z GFS AND ECMWF...ARE IN AMAZINGLY GOOD AGREEMENT WITH A STRONG MID WEEK STORM SYSTEM THAT TAKES A TRACK WEST OF THE AREA. PRIOR TO THAT TIME...THERE ARE MULTIPLE WAVES OF LOW PRESSURE MOVING OFF THE SE COAST...WITH SOME UNCERTAINTY IN THE NORTHERN EXTENT OF ONE OF THESE WAVES MON NIGHT INTO TUE. THE LATTER OF WHICH THE ECMWF IS MORE AGGRESSIVE WITH IN TAKING THE LOW THE FARTHEST NORTH...WHILE THE GGEM AND GFS ARE SUPPRESSED TO THE SOUTH. PREFERENCE THOUGH IS TOWARD A MORE AMPLIFIED PATTERN IN THE LAST 24H...SO LEANING TOWARD THE ECMWF. THIS ALL SPELLS OUT A PROLONGED PERIOD OF WET WEATHER FROM LATE SAT NIGHT INTO THE MID WEEK PERIOD. THERMO PROFILES ARE GENERALLY WARM WITH PERHAPS A LIGHT RAIN/SNOW MIX SAT NIGHT INTO SUN...PRIMARILY NORTH AND WEST OF NYC. AT THE SURFACE...HIGH PRESSURE PASSES TO THE NORTH AND EAST OF THE REGION THIS WEEKEND. A LOW-LEVEL EASTERLY FLOW INTERACTS WITH A MID LEVEL SHORT WAVE SAT NIGHT INTO SUN MORNING WITH POSSIBLY LIGHT PCPN. LOW PRESSURE THEN EMERGES OFF THE SE COAST ON SUN AND TAKES A TRACK SLOWLY NORTH THROUGH TUE. A MUCH MORE ROBUST AREA OF LOW PRESSURE THEN RAPIDLY DEEPENS ACROSS THE TN/OH VALLEYS TUE NIGHT INTO WED...EVENTUALLY WRAPPING UP OVER THE GREAT LAKES WED NIGHT INTO THU WITH PRESSURES APPROACHING 960 MB. THIS TRACK WOULD KEEP THE FORECAST AREA IN THE WARM SECTOR OF THE STORM WITH THE POTENTIAL FOR CONVECTION AND EVEN STRONG WINDS. THE CAVEAT HERE IS THAT THE STORM IS ABOUT A WEEK AWAY WITH A LOT OF TIME FOR CHANGE IN TRACK AND TIMING. IN ADDITION...THE FAST PAC FLOW WOULD LEAD ONE TO BELIEVE THAT THERE ARE GOING TO BE TIMING ISSUES WITH THE SOUTHERN BRANCH SHORT WAVE ENERGY. TEMPS OVER THE WEEKEND START OFF AT NEARLY NORMAL LEVELS AND THEM MODERATE BY MID WEEK. HIGHS NEAR 50 ON WED COULD BE UNDERDONE IF THE PATTERN AND STORM TRACK PANS OUT. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... DEEPENING LOW PRESSURE EAST OF NEW ENGLAND WILL MOVE INTO THE CANADIAN MARITIMES THROUGH THU. AS THE AREA REMAINS UNDER THE INFLUENCE OF THE LOW...MAINLY BKN040 CIGS SHOULD PREVAIL INTO EARLY THIS EVENING...EXCEPT WITH AN ISOLD CLUSTER OF SHOWERS MOVING THROUGH THAT SHOULD BRING BRIEF MVFR CONDS TO KTEB/KLGA/KHPN/KISP LATE THIS AFTERNOON OR AROUND SUNSET. THESE CIGS SHOULD THEN LIFT TO BKN060 THIS EVENING...REMAIN INTO THE NIGHT AS AN UPPER LEVEL DISTURBANCE APPROACHES AND MOVES ACROSS LATE...THEN SCATTER OUT AFTER ITS PASSAGE. COULD SEE AN ISOLD SHOWER OR TWO AS WELL LATE TONIGHT...MAINLY OUT EAST AT KGON/KBDR/KISP. W-NW WINDS LEFT OF 310 MAGNETIC AT 10-15 KT WITH GUSTS EITHER SIDE OF 20 KT SHOULD DECREASE SOMEWHAT THIS EVENING...THEN INCREASE TO NEAR 15-20G25-30KT...HIGHEST AT THE NYC METROS...AFTER MIDNIGHT AS THE UPPER LEVEL DISTURBANCE MOVES ACROSS. THESE WINDS SHOULD BACK MORE WESTERLY AND BRIEFLY DECREASE AGAIN BY ABOUT 10-11Z...THEN PICK UP BY 14Z-15Z. ...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: HIGH CONFIDENCE INTO THIS EVENING. KLGA FCSTER COMMENTS: HIGH CONFIDENCE INTO THIS EVENING. KEWR FCSTER COMMENTS: HIGH CONFIDENCE INTO THIS EVENING. KTEB FCSTER COMMENTS: HIGH CONFIDENCE INTO THIS EVENING. KHPN FCSTER COMMENTS: HIGH CONFIDENCE INTO THIS EVENING. KISP FCSTER COMMENTS: HIGH CONFIDENCE INTO THIS EVENING. .OUTLOOK FOR 21Z THU THROUGH SAT... .THU AFTERNOON/NIGHT...VFR. NW WINDS 13-18G20-25KT...DIMINISHING TO 10-15G15-20KT BY EVENING. .FRI-SAT...VFR. .SAT NIGHT...VFR TO START...THEN MVFR OR LOWER CONDS WITH LIGHT PRECIP...RAIN AT MOST TERMINALS...SNOW AT KSWF...AND RAIN OR SNOW KHPN. .SUNDAY...MVFR OR LOWER CONDS...WITH LIGHT PRECIP CHANGING TO RAIN THROUGHOUT. .MON...CHANCE OF RAIN WITH MVFR OR LOWER CONDS. && .MARINE... WINDS INCREASE TONIGHT IN RESPONSE TO CAA AND A TIGHTENING PRESSURE GRADIENT. SCA REMAINS POSTED FOR ALL WATERS THROUGH THURSDAY...WITH THE OCEAN WATERS EXTENDED THROUGH THURSDAY NIGHT AS GUSTS TO 25 KT CONTINUE. THERE MAY BE A GUST OR TWO UP TO 35 KT OVER THE EASTERN OCEAN WATERS LATE TONIGHT INTO EARLY THURSDAY MORNING...BUT NOT ENOUGH TO WARRANT A GALE WARNING. WINDS THEN SUBSIDE THROUGH FRIDAY WITH SUB-SCA CONDITIONS. SUB-ADVY CONDS ARE FORECAST SAT-MON AS HIGH PRES PASSES TO THE NORTH OF THE WATERS. WEAK LOW PRESSURE IS FORECAST TO APPROACH FROM THE SOUTH ON MON WITH A GRADUALLY STRENGTHENING NE FLOW. && .HYDROLOGY... MAINLY DRY THROUGH SATURDAY. LIGHT QPF AMOUNTS EXPECTED SAT NIGHT INTO TUE. THERE IS THE POTENTIAL FOR A MORE SIGNIFICANT RAINFALL EVENT LATE TUE INTO WED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ330-335- 338-340-345. SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355. && $$ SYNOPSIS...JC/DW NEAR TERM...JC SHORT TERM...JC LONG TERM...DW AVIATION...GOODMAN MARINE...JC/DW HYDROLOGY...JC/DW

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