Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 310022 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 822 PM EDT THU OCT 30 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN TONIGHT. LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST FRIDAY AND TRACKS NORTHEAST. A SECONDARY LOW FORMING OFF THE MID ATLANTIC COAST ON SATURDAY WILL INTENSIFY AND HEAD NORTHEAST TO THE CANADIAN MARITIMES BY SUNDAY EVENING. HIGH PRESSURE WILL BUILDS IN BEHIND THIS STORM FROM MONDAY INTO TUESDAY. A WARM FRONT WILL PASS TO THE NORTH ON TUESDAY... FOLLOWED BY A SERIES OF FAST MOVING COLD FRONTS WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... WITH THE LOSS OF DAYTIME HEATING MOST OF THE INLAND STRATO CU WAS DISSIPATING. DRIER AIR WAS FLOWING IN ON A NORTHWEST WIND. ADJUSTED TEMPERATURES AND DEW POINTS FOR CURRENT TRENDS. IN THE UPPER LEVELS...VIGOROUS SHORTWAVE AND PVA DIVES ACROSS THE UPPER MIDWEST/WESTERN GREAT LAKES REGION SOUTHWARD. ANOTHER SHORTWAVE TRACKS ACROSS THE GULF STATES...MOVING EAST TONIGHT. AT THE SURFACE...WEAK HIGH PRESSURE BUILDS IN AND MOVES QUICKLY NORTHEAST AHEAD OF THIS TROUGH. DIURNAL SCATTERED TO BROKEN CU CLOUDS SHOULD GIVE WAY TO CLEARING OVERNIGHT...ALTHOUGH DO EXPECT FEW TO SCATTERED LOWER CLOUDS THROUGH THE NIGHT. LOW TEMPS TONIGHT SHOULD BE NEAR OR SLIGHTLY BELOW NORMAL PER MOS BLEND. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... SHORTWAVE AND WEAK PVA TRACKS OFF THE MID ATLANTIC COAST...WITH SFC LOW PRESSURE DEVELOPING OFF THE CAROLINAS. MORE POTENT SHORTWAVE CARVES OUT LOW PRESSURE FRIDAY NIGHT AS IT ROUNDS THE BASE OF THE MAIN TROUGH OVER THE SOUTHEAST STATES. WEAK INVERTED TROUGH EXTENDS NW FROM THE WESTERN ATLANTIC LOW LATER FRIDAY AND FRIDAY NIGHT. WITH SOME SUPPORT ALOFT...AND A MOISTENING COLUMN DUE TO INCREASING EAST/NORTHEAST FLOW BELOW H8 HPA...EXPECT LIGHT RAIN TO DEVELOP FRIDAY AFTERNOON. RAIN CHANCES INCREASE FRIDAY NIGHT...WITH THE BETTER CHANCE ACROSS THE EASTERN ZONES. TEMPS ARE EXPECTED TO AVERAGE SLIGHTLY BELOW NORMAL DUE TO INCREASING CLOUDS AND NE FLOW. NEAR NORMAL READINGS ANTICIPATED FRIDAY NIGHT. FOLLOWED A MOS BLEND. && .LONG TERM /SATURDAY THROUGH THURSDAY/... GUIDANCE REMAINS MOSTLY CONSISTENT ON THE EVOLUTION OF A STORM DEVELOPING OFF THE COAST THIS WEEKEND. FIRST...LOW PRESSURE MOVING ALONG AN OFFSHORE FRONT WILL BRING MOSTLY LIGHT RAIN TO THE AREA...ESPECIALLY OVER ERN LONG ISLAND/SE CT WITH CAT POP...WITH LIKELY POP AS FAR BACK AS NYC METRO. THERE ARE DIFFERENCES IN TIMING AND RAINFALL AMTS DURING THE DAY SAT BETWEEN THE LATEST RUNS OF THE MODEL GUIDANCE...WITH THE LATEST GFS SOONER AND A LITTLE FARTHER EAST...AND THE ECMWF WETTER AND LATER OUT EAST...HAVE SMOOTHED OUT THESE DIFFERENCES FOR NOW WITH A GENERAL ALL DAY EVENT. FOCUS OF RAIN SHOULD GRADUALLY SHIFT TO THE EAST SAT NIGHT...WITH DECREASING POP AS THIS FIRST LOW LIFTS TO THE NE. PRECIP COULD BRIEFLY END AS SOME SNOW OR A RAIN/SNOW MIX IN THE HIGHEST ELEVATIONS WELL NORTH/WEST. AS A STRONGER LOW FORMS NEAR CAPE HATTERAS AND THEN TRACKS OUTSIDE THE 40N/70W BENCHMARK BY DAYBREAK SUNDAY...ITS RAINFALL SHOULD REMAIN OFFSHORE AS IT FAILS TO PHASE WITH THE UPPER TROUGH TO ITS WEST. ITS MORE IMPORTANT IMPACTS WILL BE AND COOLER CONDS ON SUNDAY...WITH A BRISK N FLOW AS AS THE LOW INTENSIFIES AND THE PRESSURE GRADIENT TIGHTENS AROUND BETWEEN IT AND BUILDING HIGH PRESSURE TO THE WEST. THERE SHOULD ALSO BE PLENTY OF INSTABILITY STRATOCU AS AN UPPER TROUGH MOVES ACROSS. HIGHS WILL ONLY BARELY REACH 50 IN NYC METRO AND LONG ISLAND...AND REMAIN IN THE 40S INLAND. WINDS WILL DIMINISH SOMEWHAT SUNDAY NIGHT UNDER MOSTLY CLEAR SKIES...BUT REMAIN STRONG ENOUGH TO PREVENT THE BOUNDARY LAYER FROM COMPLETELY DECOUPLING IN MOST PLACES. ASA RESULT STUCK CLOSE TO GUIDANCE LOWS FOR SUNDAY NIGHT AND DID NOT UNDERCUT...WITH LOWS 25-30 WELL INLAND...LOWER 30S MOST ELSEWHERE...AND MID 30S FOR NYC. AFTER ONE MORE COOL DAY ON MON WITH HIGHS AGAIN IN THE UPPER 40S AND LOWER 50S...TEMPS SHOULD MODERATE BACK TO NEAR NORMAL FOR THE MID WEEK PERIOD AS A WARM FRONT PASSES TO THE NORTH AND HIGH PRESSURE PASSES TO THE EAST. SHOULD THEN SEE A SERIES OF WEAK...FAST MOVING COLD FRONTS PASSING THROUGH IN FAST QUASI-ZONAL FLOW...WITH CHANCE POP FOR RAIN SHOWERS NORTH/WEST OF NYC ON WED...AND THROUGHOUT THE AREA WED NIGHT INTO THU. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
HIGH PRESSURE BUILDS NORTH AND EAST OF THE AREA THROUGH FRIDAY...WHILE LOW PRESSURE DROPS SE ACROSS THE GREAT LAKES. A SECONDARY COASTAL LOW THEN DEEPENS ON FRIDAY AND TRACKS NE OFF THE MID ATLANTIC COAST. EXPECT MAINLY VFR CONDITIONS WITH POSSIBLE MVFR CONDITIONS BY LATE FRI AFTERNOON. HIGHER CONFIDENCE IS AFTER 00Z SAT WITH THE ONSET OF -RA. WINDS CONTINUE TO VEER TO THE N OVERNIGHT AND NE ON FRIDAY. 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: NO UNSCHEDULED AMENDMENTS EXPECTED. KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .FRI NGT-SAT NGT...MVFR OR LOWER. PCPN MAINLY RAIN...BUT SNOW MAY MIX IN ACROSS THE INTERIOR SUN NIGHT. NE-N WINDS 15-20G25-35KT. .SUNDAY...MAINLY VFR. AFT STRATO CU WITH ISOLATED FLURRIES/SPRINKLES. NW WINDS 20-25G30-35KT. .MONDAY AND TUESDAY...VFR.
-- End Changed Discussion --
&& .MARINE... NORTHWEST WIND 10 TO 15 KT HAS ALLOWED FOR SEAS ON THE OCEAN TO SUBSIDE TO 2 TO 3 FT...SO HAVE ADJUSTED WAVE HEIGHTS DOWNWARD UP TO A FOOT THROUGH MUCH OF TONIGHT AS WIND WILL GRADUALLY TURN TO THE NORTH AND DIMINISH A FEW KNOTS. AS HIGH PRESSURE BUILDS THEN MOVES NORTHEASTWARD...NW WINDS WILL TURN TOWARD THE N TONIGHT. THE WINDS THEN TURN TO THE NE AND INCREASE LATER IN THE DAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. THESE E/NE WINDS INCREASE FRIDAY NIGHT...LIKELY TO SCA THRESHOLDS. RELATIVELY TRANQUIL SEAS BUILD LATE FRIDAY AND FRIDAY NIGHT AS THE WINDS INCREASE. SCA CONDS ARE LIKELY BY SAT...BUT IT IS STILL UNCERTAIN WHETHER GALES WILL DEVELOP THAT EARLY DUE TO TIMING UNCERTAINTY OF AN INITIAL LOW PASSING TO THE SE. GALES APPEAR MORE LIKELY LATE SAT NIGHT INTO SUNDAY AS STRONGER LOW PRESSURE DEVELOPS AND PASSES TO THE SE...WITH CAA OVER STILL RELATIVELY MILD WATERS AND A TIGHTENING PRESSURE GRADIENT. AFTER SOME LINGERING GALES ON THE ERN OCEAN WATERS SUNDAY EVENING...SCA CONDS SHOULD OTHERWISE FOLLOW FOR SUNDAY NIGHT INTO MON FOR MOST WATERS. THEN QUIET CONDS SHOULD RETURN TO ALL WATERS BY MON NIGHT. INCREASING SW FLOW AHEAD OF A COLD FRONT COULD BRING A RETURN OF SCA CONDS TO THE ERN OCEAN WATERS LATE TUE NIGHT-WED. && .HYDROLOGY... RAINFALL FROM FRI NIGHT THROUGH SAT NIGHT SHOULD REMAIN UNDER A HALF INCH...WITH THE HIGHER AMOUNTS GENERALLY ACROSS ERN LONG ISLAND AND SE CT. NO SIGNIFICANT HYDROLOGIC IMPACT EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM FRIDAY TO 6 AM EDT SATURDAY FOR ANZ330-335-338-340-345-350-353-355. && $$ SYNOPSIS...GOODMAN/PW NEAR TERM...MET/PW SHORT TERM...PW LONG TERM...GOODMAN AVIATION...DW MARINE...GOODMAN/MET/PW HYDROLOGY...GOODMAN/PW

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.