Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 080017 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 717 PM EST SUN FEB 7 2016 .SYNOPSIS... INTENSIFYING LOW PRESSURE ALONG THE SOUTHEAST U.S. COAST WILL TRACK TO THE NORTH TONIGHT AND WILL PASS WELL SOUTH AND EAST OF LONG ISLAND ON MONDAY. THAT LOW THEN TRACKS INTO THE CANADIAN MARITIMES MONDAY NIGHT. AN UPPER LEVEL SYSTEM WILL THEN SPIN OVER THE REGION THROUGH THE END OF THE WEEK. AN ARCTIC AIRMASS OVERSPREADS THE AREA FOR THE WEEKEND. && .NEAR TERM /THROUGH MONDAY/... MINOR TWEAKS TO TEMPERATURES AND CLOUD COVER THIS EVENING. OTHERWISE...THE FORECAST WAS ON TRACK WITH NO MAJOR CHANGES MADE. 12Z MODEL GUIDANCE ALL IN DECENT AGREEMENT...AND HAVE BROUGHT ABOUT AN INCREASE IN PRECIPITATION ACROSS THE REGION. AS A RESULT...TRENDED HIGHER WITH QPF AND SNOWFALL...AND HAVE GONE AHEAD AND ISSUED WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES FOR MUCH OF THE CWA. HIGH PRES JUST SOUTH OF THE REGION CONTINUES TO MOVE OFFSHORE THIS EVENING. MEANWHILE...LOW PRES CONTINUES TO INTENSIFY OFF THE SOUTHEAST U.S. COAST...AND THAT LOW WILL PASS EAST OF CAPE HATTERAS AFTER MIDNIGHT...AND WILL CONTINUE ON AN E-NE TRACK FROM LATE TONIGHT THROUGH MONDAY. 1035 MB HIGH PRES BUILDS INTO EASTERN CANADA...AND ANOTHER LOW DIVES INTO THE GREAT LAKES AND OHIO VALLEY FROM LATE TONIGHT THROUGH MONDAY. THE 12Z NAM/GFS/ECMWF HAVE ALL COME IN WITH THE LOW A BIT FARTHER TO THE WEST...JUST ENOUGH TO SPREAD HEAVIER PRECIPITATION INTO EASTERN AREAS. MODELS INDICATING HIGHER QPF AMOUNTS FOR THE REGION...AND WITH COLDER AIR IN PLACE...EXPECTING PRECIPITATION TO FALL AS SNOW. THE HIGHEST QPF AMOUNTS WILL FALL OVER EASTERN LONG ISLAND AND SE CT...WHERE 4 TO 8 INCHES OF SNOW IS POSSIBLE. WINTER STORM WARNINGS HAVE BEEN ISSUED FOR THOSE AREAS. ELSEWHERE...SNOW WILL BE LIGHTER OVER THE REST OF THE CWA...AND EXPECTING A SHARP CUTOFF FROM WHERE SNOW FALLS AND WHERE IT DOES NOT. WENT AHEAD AND HOISTED WINTER WEATHER ADVISORIES FOR THE REST OF CT AND LONG ISLAND...AND FOR WESTCHESTER AND NYC AS WELL...AS SNOW ACCUMULATIONS OF 2 TO 4 INCHES IS POSSIBLE IN THOSE LOCATIONS THROUGHOUT THE PERIOD. WEST OF THAT LINE...ONLY ABOUT 1 TO 3 INCHES OF SNOW IS POSSIBLE FOR NE NJ AND THE REST OF THE LOWER HUDSON VALLEY...SO NO HEADLINES ISSUED FOR THOSE AREAS. WITH A TIGHT NE PRES GRADIENT DEVELOPING...CAN EXPECT STRONG WINDS OF 15-25 MPH WITH GUSTS OCCASIONALLY AS HIGH AS 35 MPH IN THE WARNING AREAS. NOT EXPECTING 3 HOURS OF 35 MPH WINDS AND/OR VISIBILITIES LESS THAN 1/4 MILE...HENCE THE WINTER STORM WARNING AS OPPOSED TO A BLIZZARD WARNING. BUT BLIZZARD-LIKE CONDITIONS POSSIBLE IN THE WARNING AREAS. WITH A HEAVY...WET SNOW EXPECTED...DOWNED TREES AND POWER LINES ARE POSSIBLE. ELSEWHERE...WINDS WILL NOT BE QUITE AS STRONG...BUT GUSTS TO 30 MPH POSSIBLE FOR COASTAL AREAS. LOWS TONIGHT WILL DROP INTO THE MID 20S TO LOW 30S. HIGHS ON MONDAY WILL TOP OFF IN THE LOW TO MID 30S. && .SHORT TERM /MONDAY NIGHT/... SNOW TAPERS OFF MONDAY EVENING. AS LOW PRES FROM THE OHIO VALLEY TRACKS EAST...A SECONDARY LOW LOOKS TO FORM OFF THE MID-ATLANTIC COAST. HARD TO SAY WHERE THE HEAVIEST PRECIPITATION WILL SET UP...BUT LIGHT SNOW IS LIKELY THROUGH THE NIGHT. && .LONG TERM /TUESDAY 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 TWO PERIODS OF ENHANCED PRECIPITATION AS WEAK LOWS GET SPUN UP OFFSHORE IN THE TUE TIME FRAME AND WED TIME FRAME. IT IS TOO FAR OUT TO PINPOINT EXACTLY WHERE ANY HEAVIER BANDS SET UP...BUT THE POTENTIAL FOR AT LEAST A MODERATE SNOWFALL IN THE TUE-WED PERIOD IS THERE. 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 /00Z MONDAY THROUGH FRIDAY/... A WEAK COLD FRONT PUSHES SOUTH THROUGH THE AREA INTO MONDAY...AS A STRONG COASTAL LOW TRACKS TO THE SOUTH...THEN EAST OF LONG ISLAND INTO MONDAY EVENING. VFR THROUGH 07Z OR SO. THEN MVFR TO IFR CONDITIONS LIKELY TO DEVELOP IN LIGHT SNOW FROM E TO W THROUGH AROUND 13Z FOR CITY TERMINALS...AND THEN TO IFR FROM E TO W THROUGH MIDDAY. THE EXCEPTION IS AT KSWF...WHERE MVFR CONDITIONS ARE NOT EXPECTED UNTIL AROUND NOON...WITH CURRENTLY NO IFR CONDITIONS FORECAST THERE. ALSO...AT KGON/KISP...EXPECT LIFR AFTER 12Z 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. WINDS INCREASE OUT OF THE NE THEN N OVERNIGHT. IT APPEARS FREQUENT GUSTS SHOULD HOLD OFF UNTIL AROUND/JUST AFTER DAY BREAK...WITH GUSTS OF 20-30KT LIKELY...AND PEAK GUSTS UP TO 35 KT POSSIBLE AT COASTAL TERMINALS. EXCEPTION IS AT KSWF WHERE GUSTS TO ONLY AROUND 15 KT ARE FORECAST. GUSTS SHOULD BEGIN TO DIMINISH AROUND/AFTER 20Z. LIKELY SNOWFALL ACCUMULATIONS OF: LESS THAN 1 INCH FOR KSWF 1 TO 3 INCHES ACROSS KHPN/KEWR/KTEB 2 TO 5 INCHES FOR KLGA/KJFK/KBDR 4 TO 8 INCHES FOR KISP/KGON .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .MONDAY NIGHT-THURSDAY...MVFR OR LOWER LIKELY IN INTERMITTENT SNOW. N-NE WINDS G15-20KT POSSIBLE MONDAY NIGHT-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. && .MARINE... HIGH PRES OVER THE WATERS DEPARTS THIS EVENING. LOW PRES OFF THE SOUTHEAST U.S. COAST WILL TRACK TO THE E-NE AND PASS WELL SOUTH OF LONG ISLAND LATE TONIGHT THROUGH MONDAY. A TIGHT PRES GRADIENT SETS UP ON THE WATERS WITH GALE FORCE WINDS ON THE OCEAN...EASTERN LONG ISLAND SOUND...AND EASTERN LONG ISLAND BAYS AND 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. 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. HEADLINES FOR THE GALE WARNINGS AND SMALL CRAFT ADVISORIES LARGELY 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 LESS THAN A TENTH OF AN INCH WEST OF THE HUDSON RIVER TO ALMOST AN INCH OVER SE CT AND FAR EASTERN LONG ISLAND. 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 MONDAY INTO WEDNESDAY WITH A NEW MOON ON MONDAY AND A SERIES OF LOW PRESSURES AFFECTING THE REGION. AN INTENSE LOW PRESSURE TRACKING SE OF THE REGION MONDAY WILL RESULT IN NE/N WINDS INCREASING TO POTENTIALLY GALE FORCE TONIGHT AND CONTINUING INTO MONDAY. 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 MONDAY 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 ON MONDAY NIGHT...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 FROM 3 AM TO 6 PM EST MONDAY FOR CTZ007- 008-011-012. WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST MONDAY FOR CTZ005-006-009-010. COASTAL FLOOD ADVISORY FROM 10 AM TO 1 PM EST MONDAY FOR CTZ009-010. NY...WINTER STORM WARNING FROM 3 AM TO 6 PM EST MONDAY FOR NYZ078>081. COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST MONDAY FOR NYZ074-075-080-081-178-179. WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST MONDAY FOR NYZ070>075-176>179. COASTAL FLOOD ADVISORY FROM 10 AM TO 1 PM EST MONDAY FOR NYZ071-073-078-177. HIGH SURF ADVISORY FROM 1 AM MONDAY TO 7 AM EST TUESDAY FOR NYZ080-081-178-179. COASTAL FLOOD ADVISORY FROM 7 PM TO 11 PM EST MONDAY FOR NYZ075-080-178-179. COASTAL FLOOD ADVISORY FROM 10 PM MONDAY TO 1 AM EST TUESDAY FOR NYZ078-177. NJ...COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST MONDAY FOR NJZ006-106-108. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ335-338-345. GALE WARNING UNTIL 6 PM EST MONDAY FOR ANZ330-340-350-353-355. && $$ SYNOPSIS...JMC/MPS NEAR TERM...JMC/MPS SHORT TERM...MPS LONG TERM...JMC AVIATION...MALOIT MARINE...JMC/MPS HYDROLOGY...JMC/MPS TIDES/COASTAL FLOODING...NV

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