Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 200243 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 943 PM EST FRI DEC 19 2014 .SYNOPSIS... HIGH PRESSURE BUILDS IN FROM THE WEST AND MOVES OVER THE NORTHEAST INTO EARLY NEXT WEEK THOUGH SKIES REMAIN MOSTLY CLOUDY. MULTIPLE WAVES OF LOW PRESSURE WILL THEN IMPACT THE AREA TUESDAY INTO WEDNESDAY. THE FIRST BEING A WEAK COASTAL LOW THAT MOVES OFF THE MID ATLANTIC COAST MONDAY NIGHT INTO TUESDAY...FOLLOWED BY A MUCH STRONGER SYSTEM THAT TRACKS UP INTO THE GREAT LAKES BY MID WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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00Z SOUNDING HAS STRONG INVERSION WITH BASE AROUND 880 MB AND PLENTY OF MOISTURE TRAPPED BENEATH. LOTS OF STRATO CU AROUND SCATTERED TO BROKEN...AND EXPECTED TO BECOME MORE WIDESPREAD BROKEN TO OVERCAST AS INVERSION REMAINS. STILL LEANING TOWARD THE NAM FOR MOISTURE PROFILES. FORECAST ON TRACK WITH JUST SOME MINOR ADJUSTMENTS TO NEAR TERM HOURLY TEMPERATURES AND WIND.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION AS FLOW VEERS MORE NORTH NORTHEAST. CONTINUE WITH THE CLOUDS AS NAM SOUNDINGS INDICATE A DEEPENING OF THE ISOTHERMAL LAYER. ALSO - WEAK INSOLATION WITH A 25 DEGREE SUN ANGLE (WINTER SOLSTICE IS SUNDAY 603 PM). LOW LEVEL MOISTURE DEEPENS FURTHER SATURDAY NIGHT AS FLOW VEERS MORE NORTHEAST AND UPPER SHORTWAVE APPROACHES. NWP HAS BEEN PERSISTENT IN SOME VERY LIGHT PCPN OFF TO THE EAST. HAVE DROPPED POPS IN FAVOR OF A CHC FLURRY AFTER MIDNIGHT. HAVE AGAIN ADJUSTED TEMPS UP SLIGHTLY FROM MOS BASED ON EXTENSIVE CLOUD COVER. && .LONG TERM /SUNDAY THROUGH FRIDAY/... MODELS REMAIN IN GOOD OVERALL AGREEMENT WITH A FAST PAC FLOW ACROSS THE COUNTRY BRIEFLY BECOMING AMPLIFIED INTO A FULL LATITUDE TROF OVER THE MID SECTION OF THE COUNTRY BY TUE. THIS WILL RESULT IN MULTIPLE WAVES OF LOW PRESSURE IMPACTING THE AREA IN THE MON-WED TIMEFRAME BEFORE DRYING OUT ON THU. THERMO PROFILES ARE WARM ENOUGH TO SUPPORT ALL RAIN EVENTS. THE ONE EXCEPTION BEING FLURRIES AND/OR SPRINKLES SUN MORNING IN ASSOC WITH A WEAK SHORT WAVE TROF. A LARGE DOME OF HIGH PRESSURE WILL PASS TO THE NORTH AND EAST OF THE AREA SUN INTO MON...AS A SOUTHERN BRANCH STORM SYSTEM FORMS ALONG THE SE COAST AND TAKES A TRACK TO OFF THE MID ATLANTIC COAST MON NIGHT. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM ADVECTION WITH COLD AIR DAMMING ACROSS THE NE. EVEN SO...BOUNDARY LAYER TEMPS APPEAR TO BE WARM ENOUGH FOR AN ALL RAIN EVENT. RAIN DEVELOPS LATE MON AFT AND CONTINUES INTO TUE...GENERALLY ON THE LIGHT SIDE WITH UP TO HALF AN INCH POSSIBLE. THE SECOND LOW WILL BE A MORE SUBSTANTIAL SYSTEM AS STRONG PAC JET ENERGY CARVES OUT A FULL LATITUDE TROF OVER THE MID SECTION OF THE COUNTRY BY TUE...SENDING A FRONTAL WAVE NE ACROSS THE TN AND OH VALLEYS TUE INTO WED...EVENTUALLY WRAPPING UP INTO A DEEP LOW OVER THE GREAT LAKES CHRISTMAS EVE/DAY. THIS WILL RESULT IN STRONG WARM ADVECTION AHEAD OF THE COLD FRONTAL PASSAGE WED EVE. THERE HAS BEEN A SLOWER TREND WITH THE FRONTAL PASSAGE. AN ADDITIONAL ONE TO ONE AND A HALF INCHES OF RAINFALL IS POSSIBLE. THIS WILL BE OVER A 12 HOUR PERIOD. SO NOT EXPECTING ANY SIGNIFICANT FLOODING HAZARDS. IN COMPARISON TO RECENT MODEL RUNS...THE POTENTIAL FOR STRONG WINDS WED CONTINUES TO DIMINISH AS THE LOW-LEVEL JET IS WEAKER AND DISPLACED FARTHER EAST. TEMPERATURES WILL MODERATE FROM NEAR NORMAL LEVELS ON SUN TO 10 TO 15 DEGREES ABOVE NORMAL TUE-WED WITH A DEEP-LAYERED SLY FLOW OUT AHEAD OF THE AMPLIFYING UPPER TROF. CONDITIONS RETURN BACK TO SEASONABLE LEVELS AT THE END OF THE WEEK. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
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HIGH PRESSURE GRADUALLY BUILDS EAST INTO THE REGION THROUGH SATURDAY. CIGS EXPECTED TO CONTINUE TO VARY BETWEEN SCT-BKN 3000-3500 FT OVERNIGHT THROUGH SATURDAY AS MOISTURE REMAINS TRAPPED UNDER AN INVERSION. INCREASING CHANCES FOR WIDESPREAD BKN MVFR CIGS SATURDAY AFTERNOON INTO EVENING. 320-350 MAGNETIC WINDS CONTINUE TO VEER TO THE NORTH AND DECREASE OVERNIGHT. LIGHT N-NE WINDS LESS THAN 8 KT ON SATURDAY. .OUTLOOK FOR 00Z SUN THROUGH WED... .SAT NIGHT...MVFR CIGS LIKELY...WITH LIGHT SNOW SHOWERS POSSIBLE FOR CITY/COASTAL TERMINALS. LIGHT EAST TO NORTHEAST WINDS. .SUNDAY...MVFR CIGS...WITH LIGHT SNOW/RAIN SHOWERS POSSIBLE FOR CITY/COASTAL TERMINALS. LIGHT NORTHEAST WINDS. .MON...MVFR OR LOWER POSSIBLE IN E-SE FLOW. CHC OF RAIN. .MON NIGHT-TUE...IFR LIKELY AT TIMES IN RAIN...CIGS AND VSBYS. E-SE WINDS 10-20 KT. .TUE NIGHT AND WED...HIGH IMPACT EVENT POSSIBLE...IFR LIKELY WITH HEAVY RAIN AND GUSTY SE WINDS 25KT+ SHIFTING TO SW LATE WED.
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&& .MARINE...
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NORTHWEST WIND REMAINS AROUND 15 KT WITH MINIMAL GUSTS A FEW KTS HIGHER. THE WIND WAS SLOWLY DIMINISHING AS THE SURFACE PRESSURE GRADIENT WEAKENS AS HIGH BUILDS IN FROM THE WEST. THE HIGH WILL THEN GRADUALLY BUILD THROUGH SATURDAY. TRANQUIL CONDITIONS PREVAIL THROUGH THE WEEKEND. TRANQUIL CONDITIONS CONTINUE ON SUN. WINDS AND SEAS BUILD ON MONDAY WITH A TIGHTENING PRESSURE GRADIENT. SCA CONDS THEN LIKELY FOLLOW MON NIGHT AND TUES AHEAD OF MULTIPLE WAVES OF LOW PRESSURE OFF THE EAST COAST.
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&& .HYDROLOGY... NO HYDRO IMPACTS EXPECTED 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. NO HYDROLOGICAL IMPACTS EXPECTED. RAIN ON WED/WED NIGHT MAY AVERAGE 1-1.5 INCHES ACROSS THE REGION. MINOR URBAN FLOODING IS POSSIBLE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...TONGUE/DW NEAR TERM...MET SHORT TERM...TONGUE LONG TERM...DW AVIATION...NV MARINE...MET HYDROLOGY...TONGUE/DW

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