Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 201759 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 159 PM EDT MON OCT 20 2014 .SYNOPSIS... HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST TODAY. LOW PRESSURE APPROACHES FROM THE GREAT LAKES REGION TONIGHT. SECONDARY LOW PRESSURE WILL DEVELOP NEAR THE MID ATLANTIC COAST BY LATE TUESDAY...SLOWLY MEANDER ABOUT NEAR THE REGION WEDNESDAY THROUGH THURSDAY...THEN PASS EAST OF NEW ENGLAND THURSDAY NIGHT INTO FRIDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SATURDAY...THEN PASS THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL CANADA ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NOT MUCH CHANGE FROM THE PREVIOUS FORECAST WITH THIS UPDATE. SURFACE HIGH PRESSURE HAS SHIFTED OFFSHORE...RESULTING IN LIGHT SW WINDS. SUNSHINE WILL BE FILTERED THROUGH MID AND HIGHER LEVEL CLOUDS FROM TIME TO TIME THIS AFTERNOON. HIGH TEMPS AVERAGING BELOW NORMALS...MOSTLY 55-60. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... AT THE SURFACE...HIGH PRESSURE PASSES WELL EAST OF THE 40N/70W BENCHMARK AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES REGION. THE LOW IS EXPECTED TO DIVE SOUTHEASTWARD ACROSS PENNSYLVANIA DURING THE DAY TUESDAY...WITH A SECONDARY LOW DEVELOPING OFF THE MID ATLANTIC COAST LATE IN THE DAY. ALOFT...DIGGING TROUGH CLOSES OFF TUESDAY NEAR WESTERN PENNSYLVANIA PER NAM/GEFS MEAN/12Z ECMWF/CMC. FOR TONIGHT...WEAK LIFT AND DEEPENING MOISTURE MAY RESULT IN A FEW SHOWERS...ESPECIALLY AFTER MIDNIGHT. WITH THE INCREASING SOUTHERLY FLOW...EASTERN LOCALES MAY HAVE A BETTER CHANCE OF OBSERVING SOME SHOWER ACTIVITY DUE TO FETCH. WILL CAP POPS IN THE CHANCE RANGE. ON TUESDAY...AMPLE MOISTURE AND WEAK LIFT AHEAD OF THE UPPER TROUGH/CLOSED LOW SHOULD BE ENOUGH FOR A HIGHER CHANCE FOR SHOWERS. COVERAGE SHOULD INCREASE SOMEWHAT INTO THE HIGH CHANCE OR LIKELY RANGE...50 TO 60 PERCENT COVERAGE. AS FOR TEMPS...LOWS TONIGHT WILL BE CONSIDERABLY WARMER DUE TO THE CLOUD COVER AND SW FLOW. LOWS SHOULD RANGE FROM THE LOWER TO MID 40S ACROSS THE INTERIOR AND NORMAL COOL SPOTS...TO THE LOWER 50S IN AND AROUND NYC. TUESDAY/S DAYTIME TEMPS REBOUND INTO THE 60S. THESE EXPECTED HIGH/S SHOULD RUN SLIGHTLY ABOVE NORMAL LEVELS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... WX WILL BE UNSETTLED FROM TUE NIGHT THROUGH THU NIGHT AS A SLOW MOVING CLOSED LOW PLODS ACROSS THE MID ATLANTIC REGION...WITH ASSOCIATED LOW PRESSURE OFF THE MID ATLANTIC COAST THROUGH THIS TIME FRAME. BETTER UPPER LEVEL FORCING INITIALLY WILL BE MORE ACROSS NYC METRO AND THE LOWER HUDSON VALLEY THAN SRN CT/ERN LONG ISLAND...SO THE FORMER WILL MAINTAIN PREV FCST OF LIKELY POP WHILE THE LATTER WILL BE ONLY AT CHANCE. WITH THE UPPER LOW PASSING JUST TO THE SOUTH ON WED AND NAM/ECMWF SHOWING AN INVERTED TROUGH EXTENDING W-NW OF THE SFC LOW...MAY HAVE TO WATCH OUT FOR A BAND OF LOCALLY HEAVY RAIN NEAR NYC/WRN LONG ISLAND ON WED...THEN THE FOCUS OF MODERATE RAIN SHOULD SHIFT MORE EAST INTO LONG ISLAND/CT...AND WITH A STRONG MID LEVEL VORT MAX ROTATING AROUND THE CLOSED LOW...ERN CT/LONG ISLAND COULD SEE A ROUND OF HEAVY RAIN WED NIGHT. AS THIS FORCING PIVOTS AROUND THE CLOSED LOW FARTHER NORTH INTO NEW ENGLAND...RAIN SHOULD BE MORE ON THE LIGHT SIDE ON THU...THEN GRADUALLY TAPER OFF THU NIGHT AS THE NEARLY VERTICALLY STACKED LOW DRIFTS TOWARD SE NEW ENGLAND...ALLOWING A DRYING NW FLOW TO TAKE HOLD. AFTER SOME LINGERING LIGHT PRECIP EARLY ACROSS ERN SECTIONS FRI MORNING...FCST GOES DRY FOR THE REST OF THE PD. MOISTURE STARVED COLD FRONT/NRN NORTHERN STREAM TROUGH WILL PASS THROUGH SAT NIGHT...FOLLOWED BY A DRY NW FLOW ON SUNDAY. TEMPS SHOULD BE ON THE COOL SIDE UNDER THE INFLUENCE OF THE LOW THROUGH THU NIGHT...THEN RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL FOR FRI-SAT...AND NEAR NORMAL FOR SUNDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE OFF THE MID ATLANTIC COAST WILL CONTINUE TO TRACK EAST INTO THE WESTERN ATLANTIC...WHILE LOW PRESSURE APPROACHES FROM THE NW. MAINLY VFR. CHANCE OF -RA LATE TONIGHT...MAINLY KSWF AND EASTERN TERMINALS. THERE IS A LOW POTENTIAL FOR MVFR CONDITIONS AT KSWF AND KISP...WITH A BETTER CHANCE BEING AT KGON. S/SW WINDS AT 10 KT OR LESS THIS AFT...BECOMING LIGHT TONIGHT AND GRADUALLY BACKING AROUND TO THE SE TUE MORNING. 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: OCCASIONAL GUSTS TO AROUND 15 KT THIS AFT. .OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY... .TUESDAY AFT-NIGHT...OCNL MVFR CIGS IN LIGHT RAIN. .WEDNESDAY THROUGH THURSDAY...MVFR OR LOWER CONDS IN RAIN. NLY FLOW 10 TO 15 KT G20-25KT. .FRIDAY...IMPROVING CONDS. NW WINDS 15-20 KT WITH 20-25 KT GUSTS. .SATURDAY..VFR. NW G20KT. && .MARINE... WINDS CONTINUE TO DIMINISH AHEAD OF AN AREA OF HIGH PRESSURE. AS THE HIGH MOVES EAST OF THE WATERS THIS AFTERNOON...WINDS WILL INCREASE OUT OF THE SOUTH. IN FACT...WINDS MAY APPROACH SCA LEVELS BRIEFLY TONIGHT...ESPECIALLY FOR THE OCEAN WATERS. FOR THE MOST PART...EXPECT CONDITIONS TO FALL SHORT OF THE 25 KTS FOR ISSUANCE OF A SMALL CRAFT ADVISORY. HOWEVER...CANNOT RULE OUT BRIEF 20 TO 25 KT WINDS TONIGHT BEFORE WINDS DIMINISH YET AGAIN. WINDS REMAIN LIGHT FROM THE SOUTH OR SOUTHEAST ON TUESDAY AS LOW PRESSURE APPROACHES. SEAS SUBSIDE THIS MORNING...THEN MAY BUILD A FOOT OR TWO LATER TODAY AND TONIGHT AS THE SOUTHERLY WINDS INCREASE. HOWEVER...DO NOT ANTICIPATE 5 FOOTERS OVER THE OCEAN WATERS. SCA CONDS APPEAR LIKELY TO DEVELOP WED-WED NIGHT MAINLY ON THE OCEAN IN ENE FLOW TO THE NORTH OF DEVELOPING LOW PRESSURE OFF THE MID ATLANTIC COAST. THESE CONDS MAY SUBSIDE ON THU...THEN RAMP BACK UP THU NIGHT-FRI IN NW FLOW ON THE BACK SIDE OF THE DEPARTING LOW. && .HYDROLOGY... DRY TODAY...WITH SPOTTY LIGHT RAINFALL AMOUNTS POSSIBLE TONIGHT. AT LEAST AN INCH OF RAIN APPEARS LIKELY FROM TUE INTO THU. DEPENDING ON PLACEMENT OF BANDS OF HEAVIER RAIN WED INTO WED NIGHT...THERE IS POTENTIAL FOR SOME AREAS TO SEE OVER 2 INCHES OF RAIN. HYDROLOGIC IMPACTS SHOULD BE LIMITED TO NUISANCE POOR DRAINAGE FLOODING. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/PW NEAR TERM...JC/PW SHORT TERM...PW LONG TERM...GOODMAN AVIATION...DW MARINE...GOODMAN/PW HYDROLOGY...GOODMAN/PW

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