Area Forecast Discussion
Issued by NWS Upton, NY

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650
FXUS61 KOKX 021925
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
325 PM EDT MON MAY 2 2016

.SYNOPSIS...
AN AREA OF LOW PRESSURE OVER THE TENNESSEE VALLEY TONIGHT WILL
TRACK NORTHEAST...PASSING TO THE SOUTH AND EAST OF LONG ISLAND
ON TUESDAY. HIGH PRESSURE WILL THEN BRIEFLY FOLLOW FOR TUESDAY
NIGHT. A COMPLEX AND SLOW MOVING STORM SYSTEM WILL IMPACT THE
TRI-STATE FROM WEDNESDAY THROUGH SATURDAY. A COLD FRONT CROSSES
THE AREA ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A PROLONGED PERIOD OF INCLEMENT WEATHER IS ON TAP AS AN UPPER
TROF AMPLIFIES ACROSS THE EASTERN HALF OF THE COUNTRY THROUGH MID
WEEK. PRECEDING THIS TROF...WILL BE SEVERAL WAVES OF LOW
PRESSURE...THE FIRST OF WHICH EJECTS FROM THE TN VALLEY TONIGHT TO
JUST SOUTH OF THE AREA BY MORNING. 12Z GUIDANCE HAS COME INTO
BETTER AGREEMENT..ALBEIT THERE ARE SOME SMALL TIMING ISSUES...FOR
A DECENT BANDED RAIN EVENT LATE TONIGHT INTO TUE MORNING. MID
LEVEL FRONTOGENESIS COUPLED WITH A VORT APPROACHING FROM THE MID
ATLANTIC WILL PRODUCE ABOUT HALF TO ONE INCH OF RAINFALL. THE
HIGHEST AMOUNTS ARE FORECAST ACROSS LI. THE RAIN WILL DEVELOP
AFTER MIDNIGHT FROM SW TO NE WITH ABOUT A 3 TO 5 HOUR PERIOD OF
MODERATE TO OCCASIONALLY HEAVY RAINFALL.

MOST OF THE NIGHT WILL BE OVERCAST...BUT THERE MAY BE ENOUGH
DRYING IN THE BOUNDARY LAYER EARLY THIS EVE FOR SOME PARTIAL
CLEARING AHEAD OF THE APPROACHING FRONTAL WAVE. DIURNAL TEMP
RANGES WILL BE SMALL THE NEXT COUPLE OF DAYS DUE TO THE CLOUD
OVER AND NE FLOW. LOWS TONIGHT WILL BE IN THE UPPER 40S TO LOWER
50S...WHICH IS A FEW DEGREES ABOVE NORMAL.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
MODERATE RAIN WILL QUICKLY EXIT THE AREA DURING THE MORNING
HOURS...MAINLY IMPACTING AREAS EAST OF THE HUDSON RIVER. THERE IS
THE POSSIBILITY THAT SOME LIGHT RAIN COULD LINGER INTO THE
AFTERNOON WITH THE EXIT REGION OF THE UPPER LEVEL JET IN CLOSE
PROXIMITY. GENERALLY THOUGH LOOKING AT LOW RAIN CHANCES BY
AFTERNOON WITH THE DEEP MOISTURE AND LIFT PASSING WELL TO THE
EAST AND ONLY LOW-LEVEL MOISTURE ON THE BACKSIDE OF THE LOW.
AN OVERRUNNING PATTERN IN THE LOW-LEVELS WILL MAINTAIN CLOUDY
CONDITIONS THROUGH TUE NIGHT WITH A EVEN A CHANCE OF SOME LIGHT
RAIN DEVELOPING OVERNIGHT.

ONCE AGAIN...DIURNAL TEMP RANGES WILL BE SMALL...WITH HIGHS TUE
IN THE 50S...WITH LOWS TUE NIGHT ABOUT 5 DEGREES COOLER. THIS
WILL EQUATE TO WELL BELOW NORMAL HIGHS AND LOWS JUST A FEW DEGREES
ABOVE NORMAL.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
GOOD AGREEMENT AMONG THE MODELS THE REGARDING CUTOFF LOW THAT MOVES
THROUGH THE GREAT LAKES WEDNESDAY AND THEN SLOWLY TRACKS SE TOWARDS
THE MIDDLE ATLANTIC COAST BY FRIDAY. THE LOW IS THEN PROGGED TO
SLOWLY LIFT AWAY FROM THE COAST ON SATURDAY AS A NEW NORTHERN STREAM
TROUGH DIGS INTO THE GREAT LAKES REGION. THIS WILL SEND A COLD FRONT
ACROSS ON SUNDAY.

FOR WEDNESDAY...MUCH OF THE GUIDANCE IS HINTING AT SOME SHOWER
ACTIVITY AS THERE IS SOME SHORTWAVE ENERGY IN THE MID TO UPPER
LEVEL. HOWEVER...DIFFERENCES EXIST IN ANY WAVE OF LOW PRESSURE THAT
DEVELOPS ON A STALLED BOUNDARY JUST OFFSHORE. TIMING DIFFERENCES ARE
DEPICTED WITH THE LATEST MODELS WHICH LEADS TO A LOW CONFIDENCE
FORECAST. HAVE CAPPED POPS AT CHANCE CATEGORY THROUGH THE
DAY...HIGHEST IN THE AFTERNOON AND EVENING.

FOR THURSDAY INTO FRIDAY...HAVE ALSO ELECTED TO REMAIN PERSISTENT
WITH THE PREVIOUS FORECAST WITH GENERALLY CHANCE POPS. TIMING ENERGY
WITHING THE CUTOFF LOW REMAINS DIFFICULT. IT WILL NOT BE A COMPLETE
WASH OUT...BUT PERIODS OF SHOWERS MAY OCCUR AT ANY TIME. THE LATEST
DETERMINISTIC AND ENSEMBLE GUIDANCE ARE SIGNALING THAT FRIDAY MAY BE
THE DAY WITH BETTER CHANCES FOR SHOWERS. THIS IS WHEN THE CUTOFF LOW
SLOWLY LIFTS NE TOWARDS THE AREA AND A WAVE OF LOW PRESSURE COULD
DEVELOP OFF THE DELMARVA.

THE CUTOFF LOW SHOULD PULL AWAY ON SATURDAY...SO WILL SHOW A
DOWNWARD TREND IN POPS. AS THE COLD FRONT MOVES THROUGH ON
SUNDAY...POPS INCREASE BACK TO CHANCE.

AS NOTED ABOVE...THERE REMAINS A GREAT DEAL OF UNCERTAINTY INTO THE
WEEKEND. THERE WILL PERIOD OF DRY CONDITIONS AND PERIODS OF
SHOWERS...BUT TIMING OF THESE FEATURES IS STILL DIFFICULT TO
PINPOINT AT THIS TIME.

BELOW NORMAL TEMPERATURES ARE FORECAST WEDNESDAY THROUGH FRIDAY.
TEMPERATURES COULD COME CLOSE TO SEASONABLE LEVELS FOR THE
WEEKEND.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
LOW PRES SLOWLY APPROACHES NY AIRSPACE TONIGHT...AND WILL PASS SOUTH
OF LONG ISLAND LATE TONIGHT THROUGH TUESDAY.

MVFR/IFR FORECAST WITH CIGS GENERALLY 700-1200 FT THROUGH THIS
EVENING.

CIGS LOWER TO AROUND 500 FT THIS EVENING...AND VSBYS WILL DROP AS
WELL AS FOG DEVELOPS.

RAIN DEVELOPS BY DAYBREAK TUESDAY. THE HEAVIEST RAIN WILL IMPACT
KNYC/KISP. VSBYS WILL DROP TO 1SM...AND CIGS WILL BE 500 FT OR
LESS THROUGH TUESDAY MORNING. CONDS IMPROVE SLIGHTLY BY TUESDAY
AFTERNOON.

SE WINDS 10 KT OR LESS...BCMG LGT/VRB THIS EVENING. E-NE WINDS
THEN INCREASE TO 5-10 KT EARLY TUESDAY MORNING.

 ...NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.WEATHER.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: AMDS POSSIBLE FOR FLIGHT CATEGORY CHANGES.

KLGA FCSTER COMMENTS: CIGS AROUND 1000 FT THROUGH LATE AFTERNOON.

KEWR FCSTER COMMENTS: CIGS AROUND 1000 FT THROUGH LATE AFTERNOON.

KTEB FCSTER COMMENTS: AMDS POSSIBLE FOR FLIGHT CATEGORY CHANGES.

KHPN FCSTER COMMENTS: AMDS POSSIBLE FOR FLIGHT CATEGORY CHANGES.

KISP FCSTER COMMENTS: AMDS POSSIBLE FOR TIMING OF FLIGHT CATEGORY
CHANGES.

.OUTLOOK FOR 20Z TUESDAY THROUGH SATURDAY...
.TUESDAY AFTERNOON...GRADUAL IMPROVEMENTS IN THE AFTERNOON.
.TUESDAY NIGHT...IFR CONDS IN FOG/STRATUS POSSIBLE.
.WEDNESDAY THROUGH SATURDAY...PERIODS OF MVFR OR LOWER CONDS IN
RAIN/FOG/STRATUS.

&&

.MARINE...
SUB-SCA CONDS ARE FORECAST THROUGH TUE WITH THE POSSIBILITY OF A
BRIEF PERIOD OF SEAS AROUND 5 FT LATE TUE AFT/EARLY EVE.
CONFIDENCE IS LOW ENOUGH AT THIS TIME TO HOLD OFF ON THE ISSUANCE
OF AN SCA. NE WINDS INCREASE TO 10-15 KT ON THE OCEAN WATERS TUE
MORNING WITH GUSTS UP TO 20 KT...BEFORE SUBSIDING IN THE EVENING.

A RELAXED PRESSURE GRADIENT ON ALL COASTAL WATERS WILL LEAD TO WINDS
BELOW SCA LEVELS WEDNESDAY THROUGH SATURDAY. OCEAN SEAS MAY COME
CLOSE TO 5 FT AT TIMES WITH A PERSISTENT SE SWELL...MAINLY ON THE
WATERS EAST OF MORICHES INLET.

&&

.HYDROLOGY...
TOTAL RAINFALL AMOUNTS OF A QUARTER TO AN INCH IS FORECAST LATE
TONIGHT THROUGH TUESDAY MORNING. THE HIGHER AMOUNTS WILL LIKELY
FALL ACROSS NYC METRO AND LONG ISLAND...WITH THE LOWER END BEING
ACROSS NORTHERN PORTIONS OF THE LOWER HUDSON VALLEY. MINOR
NUISANCE FLOODING IN URBAN AREAS IS POSSIBLE.

PERIODS OF SHOWERS ARE POSSIBLE WEDNESDAY INTO THE WEEKEND.
CONFIDENCE ON THE TIMING AND AMOUNTS REMAIN LOW AT THIS TIME.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...DS/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DS
AVIATION...MPS
MARINE...DS/DW
HYDROLOGY...DS/DW



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