Area Forecast Discussion
Issued by NWS Upton, NY

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288 FXUS61 KOKX 081209 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 709 AM EST MON FEB 8 2016 .SYNOPSIS... AN INTENSE STORM EAST OF CAPE HATTERAS WILL MOVE NORTHEAST TODAY AND PASS SOUTH OF NOVA SCOTIA TONIGHT. AN UPPER LEVEL SYSTEM WILL THEN SPIN OVER THE REGION THROUGH THE END OF THE WEEK. AN ARCTIC AIR MASS OVERSPREADS THE AREA FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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NEAR TERM MESOSCALE UPDATE...BANDS OF MODERATE TO HEAVY SNOW ASSOCIATED WITH STRONG H7-5 FRONTOGENESIS ARE SPREADING ACROSS EASTERN LONG ISLAND AND SE CT...AND SHOULD CONTINUE SPREADING WESTWARD INTO MUCH OF THE REST OF THE AREA THROUGH THE MORNING. PRECIP COULD BE MIXED WITH RAIN AT THE VERY ONSET ALONG THE COAST...BUT THEN EVAPORATIVE/DYNAMIC COOLING FROM ALOFT SHOULD QUICKLY CHANGE PRECIP OVER TO SNOW. THE SNOW WILL BE HEAVY AT TIMES THIS MORNING ACROSS MUCH OF LONG ISLAND AND SOUTHERN CT...AND BASED ON RECENT RUNS OF THE RAP/HRRR...THE HEAVIEST SNOW BANDS SHOULD EVENTUALLY SET UP OVER CENTRAL SUFFOLK COUNTY NORTHWARD INTO NEW LONDON...MIDDLESEX AND EASTERN NEW HAVEN COUNTIES LATER THIS MORNING INTO THE EARLY AFTERNOON. EXPANDED WINTER STORM WARNING TO NEW HAVEN COUNTY EARLIER...AND ALSO INCREASED TOTALS WHERE THE HEAVIEST SNOW BANDS ARE EXPECTED...WITH 8-10 INCHES POSSIBLE AS BOTH LIFT AND DENDRITIC SNOW GROWTH ARE MAXIMIZED. WITH NE WINDS GUSTING TO 35 MPH NEAR BLIZZARD CONDS ARE LIKELY...ESPECIALLY ACROSS THE FORKS AND COASTAL SE CT. THE COMBO OF STRONG WINDS AND HEAVY SNOW COULD ALSO RESULT IN DOWNED TREES AND POWER LINES. FARTHER WEST...SNOW SHOULD BE ON THE LIGHT SIDE...WITH LIFT GENERATED A MID LEVEL SHORTWAVE APPROACHING FROM THE WEST AND THE RIGHT REAR QUAD OF AN UPPER JET STREAK OVER INTERIOR PA/NY. THESE AREAS SHOULD SEE A GENERAL 1-3 OR 2-4 INCH SNOWFALL...AND EXPANDED WINTER WX ADVY WESTWARD TO COVER ALL BUT ORANGE AND WESTERN PASSAIC COUNTIES. TEMPS AFTER SNOW BEGINS WILL FALL TO NEAR FREEZING...THEN BEGIN TO SLOWLY FALL THIS AFTERNOON.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... STEADY SNOW SHOULD TAPER OFF THIS EVENING. AS AN UPPER TROUGH TRACKS EAST...SFC LOW PRESSURE WILL FORM OFF THE MID ATLANTIC COAST...AND BRING LIGHT SNOW LATE TONIGHT INTO TUE NIGHT. AN INVERTED TROUGH WILL EXTEND W FROM THIS OFFSHORE LOW...AND COULD BE THE FOCUS FOR SOME MODERATE TO HEAVY SNOW JUST TO ITS NORTH. HARD TO SAY EXACTLY WHERE THIS WILL SET UP ATTM...AND BEARS WATCHING ESPECIALLY FOR NYC METRO AND LONG ISLAND. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH RESPECT TO THE PATTERN THROUGH THE END OF THE WEEK. CYCLONIC FLOW ALOFT PLUS LOW LEVEL LAPSE RATES APPROACHING DRY ADIABATIC AT TIMES WILL PRODUCE PERIODS OF LIGHT SNOW. WET BULB ZERO HEIGHTS AT OR BELOW 500FT THROUGH THE PERIOD SO ALL SNOW IS FORECAST. BREAKS IN THE CLOUDS WILL BE NEEDED FOR TEMPERATURES TO REACH SUPERBLEND NUMBERS...SO DROPPED THEM DOWN A DEGREE FOR NOW. FOR SNOW ACCUMULATIONS... MAINLY LIGHT AMOUNTS IN THE GRIDS AT THIS TIME. HOWEVER...THERE IS THE POTENTIAL FOR A PERIOD ENHANCED PRECIPITATION ON WED. A FIRST WAVE OF COLDER AIR COMES IN ON THU. VERY STEEP LOW LEVEL LAPSE RATES AGAIN SO ANY MOISTURE IN THE AREA SHOULD BE SQUEEZED OUT WITH MORE LIGHT SNOW. SNOW CHANCES LESSEN ON FRI AT THIS TIME WITH THE MID LEVEL MOISTURE EXITING THE AREA. THE ARCTIC FRONT LOOKS TO BE FRI NIGHT SETTING THE STAGE FOR A FRIGID WEEKEND. PERHAPS SOME FLURRIES OR SNOW SHOWERS SAT...THEN DRY ON SUN WITH A 1040S HI BUILDING IN FROM THE W. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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DEEP LOW PRESSURE OVER THE WESTERN ATLANTIC WILL PASS TO THE EAST TODAY. ANY LINGERING INITIAL VFR CONDITIONS WILL DETERIORATE FROM EAST TO WEST AS SNOW MOVES IN. THERE WILL BE A FINE LINE AND SHARP GRADIENT FROM THE LIGHTER SNOW AND HEAVIER SNOW...BUT AT THIS TIME...WOULD EXPECT TERMINALS EAST OF NYC METRO TO EXPERIENCE THE BRUNT OF THE STORM/SNOW. MVFR TO IFR CONDITIONS LIKELY TO DEVELOP IN LIGHT SNOW FROM E TO W THROUGH AROUND 14Z FOR CITY TERMINALS...AND THEN TO IFR FROM E TO W THROUGH MIDDAY. ALSO...AT KGON/KISP...EXPECT LIFR AFTER 13Z THROUGH 19-20Z WITH MODERATE TO HEAVY SNOW. THERE IS A LOW CHANCE FOR LIFR AT CITY TERMINALS AND KBDR. CONDITIONS SHOULD IMPROVE TO MVFR AT CITY TERMINALS AROUND 20Z-21Z. GUSTY WINDS CONTINUE OUT OF THE NE/N THIS MORNING. GUSTS OF 20-30 KT ARE LIKELY THIS MORNING...AND PEAK GUSTS UP TO 35 KT POSSIBLE AT COASTAL TERMINALS. EXCEPTION IS AT KSWF WHERE GUSTS TO ONLY AROUND 20 KT ARE FORECAST. GUSTS SHOULD BEGIN TO DIMINISH AROUND/AFTER 20Z. FOR TONIGHT...NE WINDS LIGHTEN. MVFR SHOULD PREVAILS. ON AND OFF LIGHT SNOW OR FLURRIES ARE POSSIBLE OVERNIGHT. LIKELY SNOWFALL ACCUMULATIONS OF: AROUND 1 INCH FOR KSWF. 1 TO 2 INCHES ACROSS KEWR/KTEB. 2 TO 3 INCHES FOR KLGA/KJFK 2 TO 5 INCHES FOR KHPN/KBDR. 4 TO 8 INCHES FOR KISP/KGON. 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: TIMING OF MVFR TO IFR MAY BE OFF AN HOUR OR TWO AS SNOW APPROACHES FROM THE EAST. SNOW ACCUM OF 2 TO 3 INCHES. KLGA FCSTER COMMENTS: TIMING OF MVFR TO IFR MAY BE OFF AN HOUR OR TWO AS SNOW APPROACHES FROM THE EAST. SNOW ACCUM OF 2 TO 3 INCHES. KEWR FCSTER COMMENTS: IFR IS POSSIBLE IF HIGHER INTENSITY SNOW MOVES IN FROM THE EAST. SNOW ACCUM OF 1 TO 2 INCHES. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: IFR IS POSSIBLE IF HIGHER INTENSITY SNOW MOVES IN FROM THE EAST. SNOW ACCUM OF 1 TO 2 INCHES. KHPN FCSTER COMMENTS: TIMING OF MVFR TO IFR MAY BE OFF AN HOUR OR TWO AS SNOW APPROACHES FROM THE EAST. SNOW ACCUM OF 2 TO 4 INCHES. KISP FCSTER COMMENTS: TIMING OF IFR TO LIFR MAY BE OFF AN HOUR OR TWO AS HEAVIER SNOW APPROACHES FROM THE EAST. SNOW ACCUM OF AROUND 4 TO 8 INCHES. NEAR BLIZZARD CONDITIONS ARE POSSIBLE FOR A TIME LATE MORNING INTO THE EARLY AFTERNOON. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .TUESDAY-THURSDAY...MVFR OR LOWER LIKELY IN INTERMITTENT SNOW. N-NE WINDS G15-20KT POSSIBLE TUESDAY-TUESDAY NIGHT...THEN W-NW WINDS G15-25 KT POSSIBLE WEDNESDAY-THURSDAY. .THURSDAY NIGHT-FRIDAY...MAINLY VFR...BUT POTENTIAL FOR SCATTERED MVFR CONDITIONS IN STRATO-CUMULUS AND FLURRIES. W-NW WINDS G15-25KT POSSIBLE.
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&& .MARINE... DEEPENING LOW PRESSURE WILL PASS SOUTHEAST OF LONG ISLAND TODAY. EXPECT A TIGHT PRESSURE GRADIENT OVER THE WATERS WITH GALE FORCE WINDS ON THE OCEAN...EASTERN LONG ISLAND SOUND...AND EASTERN LONG ISLAND BAYS. SMALL CRAFT ADVISORY LEVEL WINDS ON NY HARBOR...WESTERN LONG ISLAND SOUND...AND THE SOUTH SHORE BAYS. A FEW GUSTS TO STORM FORCE ARE POSSIBLE ON EASTERN OCEAN WATERS...BUT CONFIDENCE NOT HIGH ENOUGH TO UPGRADE TO A WARNING. ALSO...A FEW GALE FORCE GUSTS WILL BE POSSIBLE ON THE SOUTH SHORE BAYS...BUT CONFIDENCE NOT HIGH ENOUGH TO UPGRADE TO GALES. WINDS DIMINISH FAIRLY QUICKLY MONDAY EVENING AS LOW PRES DEPARTS. SEAS ON THE OCEAN WILL REMAIN HIGH...AS IT WILL TAKE SOME TIME FOR THE SEAS TO SETTLE...AT LEAST BACK TO SUB-SCA LEVELS. HEADLINES FOR THE GALE WARNINGS AND SMALL CRAFT ADVISORIES REMAIN UNCHANGED. SCA CONDITIONS ON THE OCEAN TUE-SAT. PERIODS OF SCA LEVEL WINDS LIKELY IN THE TUE-SAT PERIOD ELSEWHERE. && .HYDROLOGY... LIQUID EQUIVALENT QPF WILL RANGE FROM 1/10-1/4 INCH WEST OF THE HUDSON...TO 1/4-1/2 INCH NYC AND WESTERN LONG ISLAND/CT...TO 1/2-3/4 INCH EASTERN LONG ISLAND/CT. THE PRECIPITATION WILL FALL AS SNOW...SO NO HYDROLOGIC PROBLEMS ANTICIPATED. MEASURABLE PRECIPITATION IS THEN LIKELY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. AMOUNTS APPEAR TO BE GENERALLY LIGHT AT THIS TIME AND ALL IN THE FORM OF SNOW. && .TIDES/COASTAL FLOODING... POTENTIAL FOR MINOR TO LOCALLY MODERATE COASTAL IMPACTS TODAY INTO WEDNESDAY. NEW MOON TODAY...AND A SERIES OF LOW PRESSURES WILL AFFECT THE REGION. AN INTENSE LOW PRESSURE TRACKS SE OF THE REGION TODAY AND WILL RESULT IN STRONG NE/N WINDS. 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 WINDS TO BE BACKED MORE TO THE N THAN NE. THIS SHOULD FAVOR THE LOWER SURGE GUIDANCE FOR THE MORNING AND NIGHT HIGH TIDE CYCLES...WHICH WILL KEEP FLOODING MINOR AND LIMITED TO THE TYPICALLY VULNERABLE LOCALES. ISOLATED MODERATE FLOODING POSSIBLE ALONG THE MOST VULNERABLE SHORE BAYS OF NASSAU COUNTY. DUE TO THE LOWER ASTRONOMICAL TIDES TONIGHT AND LIGHTENING WINDS...WATER LEVELS SHOULD BE A BIT LOWER...WITH MINOR FLOODING MAINLY LIMITED TO THE SOUTH SHORE BAYS OF LONG ISLAND/NY AND ALONG THE NORTH SHORE OF LONG ISLAND ADJACENT TO WESTERN LONG ISLAND SOUND. AS WE HEAD INTO TUESDAYS HIGH TIDE CYCLES...WINDS SHOULD 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 FLOODING IN THE SOUTH SHORE BAY AREAS TUESDAY. SURGE SHOULD DECREASE HEADING INTO WEDNESDAYS HIGH TIDE CYCLE...BUT LINGERING MINOR COASTAL FLOODING IS STILL POSSIBLE...PARTICULARLY INT HE SOUTH SHORE BAYS AREAS. HIGH SURF OF 6 TO 10 FT WILL ONCE AGAIN PRESENT A MODERATE TO HIGH THREAT FOR AREAS OF DUNE TOE EROSION ALONG THE ATLANTIC OCEAN BEACHES...AND A LOCALIZED POTENTIAL FOR OVERWASHES ON FIRE ISLAND. THIS IS BASED ON MODELED IMPACTS OF GALE CENTER FROM THE USGS COASTAL CHANGE HAZARDS PORTAL. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR CTZ006>008-010>012. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR CTZ005- 009. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR CTZ009-010. NY...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ078>081. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ068>075-176>179. COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ074- 075-080-081-178-179. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR NYZ071-073-078-177. HIGH SURF ADVISORY UNTIL 7 AM EST TUESDAY FOR NYZ080-081-178- 179. COASTAL FLOOD ADVISORY FROM 7 PM TO 11 PM EST THIS EVENING FOR NYZ075-080-178-179. COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EST TUESDAY FOR NYZ078-177. NJ...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NJZ004- 006-103>108. COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NJZ006- 106-108. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ335- 338-345. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ330-340-350- 353-355. && $$ SYNOPSIS...JMC/GOODMAN NEAR TERM...GOODMAN SHORT TERM...GOODMAN LONG TERM...JMC AVIATION...PW MARINE...BC/JMC HYDROLOGY...JMC/GOODMAN TIDES/COASTAL FLOODING...PW

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