Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 190136 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 836 PM EST THU DEC 18 2014 .SYNOPSIS... HIGH PRESSURE FROM THE GREAT LAKES BUILDS OVER THE NORTHEAST THROUGH THE WEEKEND. LOW PRESSURE WILL PASS SOUTH OF THE AREA MONDAY AND MONDAY NIGHT. STRONG LOW PRESSURE WILL IMPACT THE REGION TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. && .NEAR TERM /THROUGH FRIDAY/... CLOUD COVER FCST REMAINS TRICKY. STRATO-CU FROM MOISTURE TRAPPED UNDER A STRONG INVERSION AT 900 HPA HAS SCATTERED OUT FOR A GOOD PORTION OF THE REGION FOR NOW. HAVE FOLLOWED CLOSE TO A BLEND OF NAM AND GFS MOS ALONG WITH PERSISTENCE FOR THE OVERNIGHT CLOUD COVER. WINDS DIMINISH WITH SUNSET...BUT REMAIN UP OVERNIGHT IN THE 5-10 KT RANGE (AROUND 10 IN THE NY METRO). MOS MIN TEMP GUIDANCE IS CLOSE. HAVE MATCHED FCST TO THE NAM WHICH IS A DEGREE OR SO COLDER THAT GFS WHICH MAY HAVE OVERDONE THE CLOUD COVER. && .SHORT TERM /FRIDAY NIGHT/... CLOUD COVER FCST IS AGAIN THE ONLY ISSUE SEEN AS HIGH PRESSURE BUILDS IN FROM THE WEST. NORTHERLY WINDS GRADUALLY DIMINISH AND VEER NE FRIDAY NIGHT. MOS BLEND SEEMS VERY REASONABLE AND WAS ACCEPTED FOR MAXES AND MINS. TEMPS ARE VERY CLOSE TO...IF NOT EXACTLY...SEASONABLE. NOTE THAT THE HIGH CLOUDS CURRENTLY IN OHIO WILL PASS ACROSS THE LOCAL AREA THIS EVENING INTO THE OVERNIGHT. MAY HAVE UNDERDONE THIS IN THE SKY COVER GRIDS - DEPENDING ON IF IT TURNS MORE OPAQUE THAN EXPECTED. && .LONG TERM /SATURDAY THROUGH THURSDAY/... MAIN FEATURE DURING THE LONG TERM PERIOD WILL BE DEVELOPING LOW PRESSURE THAT WILL IMPACT THE REGION ON CHRISTMAS EVE. SFC HIGH PRES CURRENTLY OVER THE GREAT LAKES WILL BUILD EAST AND PARK ITSELF NEARLY OVERHEAD THIS WEEKEND. MEANWHILE...A SERIES OF 500 MB SHORTWAVES WILL PASS THROUGH THE REGION DURING THIS TIME. WITH A LACK OF SFC MOISTURE AND LIMITED LIFT...NOT EXPECTING MUCH THAN SOME LIGHT RAIN AND/OR SNOW...AND WILL CAP POPS AT SLIGHT CHANCE FOR SATURDAY AFTERNOON THROUGH SUNDAY. TEMPS THIS WEEKEND WILL BE WITHIN A FEW DEGREES OR NORMAL...TOPPING OFF IN THE UPPER 30S TO AROUND 40 ON SATURDAY AND IN THE LOW 40S ON SUNDAY. A NEW MOON ON SUNDAY...ALONG WITH AN ONSHORE FLOW...MAY RESULT IN MINOR COASTAL FLOODING FOR THE START OF THE NEW WEEK. HIGH PRES MOVES OFFSHORE ON MONDAY. DEEP UPPER TROUGH WILL DIG INTO THE CENTRAL STATES WITH LOW PRES DEVELOPING ON MONDAY. SFC LOW PRES WILL ALSO DEVELOP AT THE BASE OF THE TROUGH IN THE GULF COAST STATES. THE SECONDARY LOW MOVES TOWARDS THE MID-ATLANTIC DURING THE DAY MONDAY BEFORE PASSING SOUTH OF LONG ISLAND MONDAY NIGHT THROUGH TUESDAY. THE PARENT LOW AND DEEP UPPER TROUGH WILL BOTH CONTINUE TO TRACK EAST EARLY IN THE NEW WEEK...AND THEN ANOTHER LOW WILL THEN FORM OVER THE MID-ATLANTIC AS SEVERAL STRONG SHORTWAVES DIVE INTO THE BASE OF THE TROUGH OVER THE GULF COAST. THIS NEW LOW WILL INTENSIFY AS IT TRACKS ALONG THE COAST ON CHRISTMAS EVE. MODELS IN GOOD AGREEMENT WITH THE LOW PASSING OVER NYC AND INTO NEW ENGLAND. THIS WILL KEEP THE REGION IN THE WARM SECTOR AND PCPN WILL BE ALL RAIN...AND MAY BE HEAVY AT TIMES. CANNOT RULE OUT CONVECTION AND POSSIBLE STREET FLOODING DURING THE DAY AS WELL. A COLD FRONT WILL SWING THROUGH THE REGION WEDNESDAY NIGHT BEHIND THE DEPARTING LOW...USHERING A COLDER AIR MASS INTO THE REGION. LATEST ECMWF HAS THE LOW STARTING OUT AS 993 MB NEAR CAPE HATTERAS AT 12Z WEDNESDAY BEFORE ENDING UP AS A 965 MB LOW OVER WESTERN QUEBEC AT 12Z THURSDAY. WITH A 28 MB DROP IN 24 HOURS...CAN EXPECT STRONG WESTERLY WINDS...POSSIBLY TO WIND ADVISORY CRITERIA... TO DEVELOP ON CHRISTMAS DAY. ALTHOUGH MODELS ARE IN GOOD AGREEMENT...THIS SYSTEM IS STILL A WEEK AWAY...AND MANY THINGS CAN CHANGE BEFORE THEN. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... DEEPENING LOW PRESSURE WILL DRIFT THROUGH THE CANADIAN MARITIMES THROUGH THE TAF PERIOD. SCT 035-040 CIGS OVERNIGHT WITH GUSTS DIMINISH THIS EVENING. ON FRIDAY...SCT-BKN 035-040 CIGS...WITH LOW PROB OF MVFR CIGS AT KSWF/KHPN IN MORN/AFT. WINDS GENERALLY 320-360 DEGREE MAGNETIC WITH SPEEDS OF 10-15 KT GUSTS NEAR 20 KT. 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: WINDS GENERALLY RIGHT OF 310 MAGNETIC. KLGA FCSTER COMMENTS: WINDS GENERALLY RIGHT OF 310 MAGNETIC. KEWR FCSTER COMMENTS: WINDS GENERALLY RIGHT OF 310 MAGNETIC. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ARE EXPECTED. KHPN FCSTER COMMENTS: LOW PROB OF 3000 FT CIGS FRI MORNING INTO AFTERNOON. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ARE EXPECTED. .OUTLOOK FOR 00Z SAT THROUGH WED... .FRI NIGHT-SAT...VFR. .SAT NIGHT...MVFR OR LOWER IN CIGS. LIGHT EAST WINDS. .SUNDAY...MVFR OR LOWER IN CIGS. LIGHT EAST WINDS. .MON...VFR. MVFR OR LOWER POSSIBLE IN ONSHORE SE FLOW. .MON NIGHT-TUE...IFR LIKELY AT TIMES IN RAIN...CIGS AND VSBYS. SE WINDS 10-20 KT. .WED...HIGH IMPACT EVENT POSSIBLE...IFR LIKELY WITH HEAVY RAIN AND STRONG GUSTY SE WINDS 25KT+ SHIFTING TO W LATE. && .MARINE...
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THE PRESSURE GRADIENT HAS WEAKENED ENOUGH THAT THE WIND AND GUSTS ACROSS THE LONG ISLAND BAYS...NEW YORK HARBOR AND LONG ISLAND SOUND HAVE DIMINISHED BELOW SMALL CRAFT LEVELS. THEREFORE THE ADVISORY HAS BEEN CANCELLED. WIND GUSTS REMAIN ABOVE 25 KT ON THE OCEAN WATERS AND SEAS WERE SLOWLY SUBSIDING...AROUND 4 AND A HALF FEET. EXPECTED GUST NEXT FEW HOURS TO REMAIN AROUND 25 KT AND WILL CONTINUE THE SMALL CRAFT FOR THE OCEAN WATERS. HIGH PRES BUILDS FROM THE W ON FRIDAY WITH TRANQUIL CONDS ON THE WATERS THAT CONTINUE INTO MONDAY. LOW PRES PASSES SOUTH OF LONG ISLAND MONDAY NIGHT AND TUESDAY...AND CONDS MAY BUILD TO SCA LEVELS DURING THAT TIME. A STRONGER LOW WILL IMPACT THE WATERS WEDNESDAY THROUGH THURSDAY...RESULTING IN AT LEAST SMALL CRAFT ADVISORY CONDS ON THE WATERS WITH GALES POSSIBLE STARTING ON THURSDAY.
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&& .HYDROLOGY... NO MEASURABLE PCPN THROUGH SAT WITH NO HYDRO IMPACTS INTO EARLY NEXT WEEK. 1/4 TO 1/2 INCH OF RAIN IS POSSIBLE MONDAY AFTERNOON THROUGH TUESDAY AS LOW PRES PASSES SOUTH OF LONG ISLAND. SOME WET SNOW IS POSSIBLE MONDAY AFTERNOON...AND THEN AGAIN MONDAY NIGHT ACROSS THE LOWER HUDSON VALLEY AND INTERIOR PORTIONS OF SOUTHERN CT. NO HYDROLOGICAL IMPACTS EXPECTED. RAIN ON WEDNESDAY MAY AVERAGE 1-2 INCHES ACROSS THE REGION. MINOR STREET FLOODING IS POSSIBLE. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355.
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&& $$ SYNOPSIS...MPS/TONGUE NEAR TERM...MET/TONGUE SHORT TERM...TONGUE LONG TERM...MPS AVIATION...NV MARINE...MPS/MET/TONGUE HYDROLOGY...MPS/TONGUE

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