Area Forecast Discussion
Issued by NWS Upton, NY

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843
FXUS61 KOKX 032349
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
649 PM EST WED FEB 3 2016

.SYNOPSIS...
A WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING FOLLOWED BY
A COLD FRONT LATE TONIGHT. LOW PRESSURE WILL DEVELOP ALONG THIS
FRONT OFF THE MID ATLANTIC COAST AND TRACK NORTHEAST PASSING
OFFSHORE FRIDAY. HIGH PRESSURE MOVES EAST ACROSS THE AREA THROUGH
SUNDAY FOLLOWED BY IMPACTS FROM POTENTIAL COASTAL STORMS MONDAY
THROUGH TUESDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
NO SIGNIFICANT CHANGES MADE TO THE OVERALL FORECAST AS MODERATE
TO HEAVY RAIN CONTINUES TO SPREAD ACROSS THE REGION AHEAD OF AN
APPROACHING WARM FRONT MVG NORTH THIS EVENING. A COLD FRONT MOVES
ACROSS THE REGION TOWARDS DAYBREAK THURSDAY.

STORM TOTAL RAINFALL FORECASTS AREA WIDE REMAIN 1-1.5 INCHES WITH
MINOR URBAN FLOODING OF LOW LYING POOR DRAINAGE AREAS WITH MAXIMUM
ESTIMATED HOURLY RATES OF 1/4 TO 1/2 INCH.

STEEP LOW LVL INVERSIONS ABOVE THE BOUNDARY LAYER WILL PREVENT
STRONG WIND GUSTS FROM MIXING DOWN TOWARD THE SURFACE.

OTHERWISE...TEMPS WILL REMAIN WELL ABOVE NORMAL TONIGHT WITH LOWS
40-50 DEGREES.

A WEAK HIGH PRESSURE RIDGE BEHIND THE FRONT WILL ALLOW DRIER AIR
TO FILTER ACROSS THE REGION THURSDAY WITH DAY TIME HIGHS IN THE
50S.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
POTENTIAL FOR AN ACCUMULATING WET SNOW AFTER MIDNIGHT THURSDAY
THROUGH FRIDAY MORNING MAINLY EAST OF NYC ACROSS LONG ISLAND AND
SOUTHERN CT.

MODELS SHOW AN AMPLIFYING SHORT WAVE DIGGING SE AND BECOMING
SLIGHTLY NEGATIVE...ALLOWING LOW PRES TO DEVELOP CLOSER TO THE
COAST THU NIGHT AND ITS ASSOCIATED PRECIP SHIELD TO EXPAND FURTHER
NORTH AND WEST THAN PREVIOUS FORECASTS.

ALTHOUGH THERMAL PROFILES ARE MARGINAL AS THE PRECIP DEVELOPS
AFTER MIDNIGHT THU NIGHT...THE ATMOSPHERE DOES COOL AND LIGHT
RAIN..QUICKLY MIXES WITH AND CHANGES TO SNOW.

BEFORE THE SNOW ENDS FRIDAY MORNING...
THE MOST LIKELY FCST...1-3 INCHES ACROSS LONG ISLAND AND SE CT
WITH LESS THAN 1 INCH FOR NYC.

THE FORECAST UNCERTAINTY...

A SHIFT IN THE TRACK FURTHER WEST COULD RESULT IN UP TO 3-6
INCHES ACROSS LONG ISLAND AND SOUTHERN CT WITH HIGH IMPACT DURING
THE FRIDAY MORNING COMMUTE.

A SHIFT FURTHER EAST...A DUSTING OF LESS THAN 1 INCH OR NO SNOW.

STAY TUNED. A WINTER WEATHER ADVISORY IS NOT OUT OF THE QUESTION
FOR THIS POTENTIAL EVENT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NWP MODEL SUITE IS IN GOOD AGREEMENT WITH THE H5 FLOW INTO THE
WEEKEND...BUT THEN DIFFERENCES WITH TIMING AND AMPLITUDE DEVELOP
LEADING TO LOW CONFIDENCE IN THE FORECAST DETAILS FOR THE FIRST
HALF OF NEXT WEEK. THIS IS ALSO APPARENT IN THE SUNY SB ENSEMBLE
SENSITIVITY ANALYSIS WHICH IS INDICATING VARIABILITY IN THE
AMPLIFICATION OF THE H5 FLOW BEGINNING FRI. THIS IS THE REASON WHY
THE FORECAST FOR EARLY NEXT WEEK REMAINS UNCERTAIN.

A SPLIT FLOW ACROSS EASTERN NOAM WILL START THE FORECAST
PERIOD...GIVING WAY TO A DIGGING TROUGH EARLY NEXT WEEK AS A HIGH
AMPLITUDE RIDGE BUILDS OUT WEST. THIS WILL TRANSLATE TO
PROGRESSIVELY COLDER TEMPERATURES BY THE MIDDLE OF NEXT WEEK.

AT THE SFC...HIGH PRES BUILDS OVER THE MID ATLANTIC STATES FRI NIGHT
AND WEAKENS AS IT SLIDES OFFSHORE ON SAT. A WEAKENING COLD FRONT
APPROACHES SAT NIGHT...MOVING THROUGH DRY ON SUN. MEANWHILE...THE
SOUTHERN STREAM WILL BE CUTTING OFF OVER THE SOUTHEAST STATES WITH
CYCLOGENESIS OCCURRING OFF THE COAST SAT NIGHT. THE MODELS HAVE
CONSISTENTLY BEEN TRACKING THIS SYSTEM WELL OUTSIDE OF THE 40N 70W
BENCHMARK. ALTHOUGH THE 12Z/03 ECMWF IS NOW THROWING SOME QPF BACK
INTO AREAS E OF NYC...FEEL THIS IS OVERDONE...AND HAVE KEPT THE
FORECAST DRY FOR MON. IF THE TRACK SHIFTS BACK TO THE WEST ONCE
BETTER SAMPLING OF THE ENERGY ASSOCIATED WITH THIS SYSTEM IS
CAPTURED WHEN IT MOVES ONSHORE...THEN POPS WOULD NEED TO BE RAISED.

THE NEXT COASTAL STORM IS SLATED FOR LATE MON NIGHT INTO TUE NIGHT.
THIS TRACK OF THIS SYSTEM HAS BEEN ALL OVER THE PLACE THE LAST FEW
DAYS AND IS ALSO IMPACTED BY THE LACK OF DATA AVAILABLE OVER THE
PACIFIC. DECIDED IT WAS BEST TO STICK WITH CONTINUITY UNTIL THINGS
CAN BE BETTER RESOLVED AND HAVE NOT MADE MUCH CHANGE TO THE FORECAST
DURING THIS TIME. HOWEVER...THE SIGNAL FOR A MILLER TYPE B STORM
REMAINS...BUT TIMING...STRENGTH AND P-TYPE REMAIN UNCERTAIN.

THINGS DRY OUT ON WED...ALTHOUGH COULD SEE SOME LAKE EFFECT ACROSS
NW ZONES.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WEST OF THE REGION WILL SLOWLY PASS THROUGH THE AREA
LATE TONIGHT...STALLING SOUTHEAST OF THE TERMINALS ON THURSDAY.

WITH PLENTY OF LOW LEVEL MOISTURE AND RAIN...EXPECT MVFR...IFR AND
LIFR CONDITIONS THROUGH MUCH OF THE OVERNIGHT. BELIEVE LIFR CIGS AND
VSBYS ARE MORE LIKELY AFTER MIDNIGHT.

THEN CONDITIONS IMPROVE THURSDAY MORNING...FROM 11-14Z. MAINLY VFR
ANTICIPATED FROM 14Z ONWARD THURSDAY.

WINDS REMAIN SOUTHERLY...THEN BEGIN TO TURN TOWARD THE SW...THEN
WEST BY THE MORNING PUSH. ON THURSDAY...WINDS TURN TO THE W/NW
BEHIND THE FRONT.

LOW LEVEL WIND SHEAR WILL CONTINUE THIS EVENING.

   ...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: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR OR LIFR SHOULD PREVAIL OVERNIGHT. ON
THURSDAY...WINDS SHOULD REMAIN JUST TO THE LEFT OF 310 MAGNETIC
UNTIL LATE IN THE AFTERNOON.

KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR OR LIFR SHOULD PREVAIL OVERNIGHT. ON
THURSDAY...WINDS SHOULD REMAIN JUST TO THE LEFT OF 310 MAGNETIC
UNTIL LATE IN THE AFTERNOON.

KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR OR LIFR SHOULD PREVAIL OVERNIGHT. ON
THURSDAY...WINDS SHOULD REMAIN JUST TO THE LEFT OF 310 MAGNETIC
UNTIL LATE IN THE AFTERNOON.

KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR OR LIFR SHOULD PREVAIL OVERNIGHT. ON
THURSDAY...CONDITIONS IMPROVE TO VFR BY 13-14Z.

KHPN FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR/LIFR SHOULD PREVAIL OVERNIGHT.
ON THURSDAY...CONDITIONS IMPROVE TO VFR BY 13-15Z.

KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. IFR/LIFR SHOULD PREVAIL OVERNIGHT. ON
THURSDAY...CONDITIONS IMPROVE TO VFR BY 13-15Z.

.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.THURSDAY NIGHT-FRIDAY...VFR CONDITIONS EXCEPT SUB-VFR IS
POSSIBLE...MAINLY EAST OF NYC METRO THURSDAY NIGHT IN LIGHT SNOW.
WNW-NW WINDS G15-20 KT POSSIBLE DURING THE DAY.
.FRIDAY NIGHT-MONDAY...VFR. SW WINDS G15-20KT POSSIBLE DURING THE
DAY ON SATURDAY.

&&

.MARINE...
WILL CANCEL THE GALE WARNING FOR THE OCEAN WATERS AS GUSTS SHOULD
BE CAPPED AT 30 KT OR SO. CANNOT RULE OUT A STRAY 35 KT GUST...BUT
ANY GALE GUSTS ARE NOT EXPECTED TO BE WIDESPREAD...SO WILL
DOWNGRADE TO SMALL CRAFT ADVISORIES ON THE OCEAN WATERS. WITH SEAS
EXPECTED TO REMAIN 6-9 FT FOR AT LEAST THE NEXT 3 PERIODS...WILL
RUN THE SCA THROUGH LATE THURSDAY NIGHT.

SMALL CRAFT ADVISORY/SCA FOR WIND GUSTS NEAR 30 KT CONTINUE
ACROSS THE REST OF THE COASTAL WATERS UNTIL MIDNIGHT.

A WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING...CAUSING
WINDS TO SHIFT FROM THE SE TO SW...FOLLOWED BY A COLD FRONT LATE
TONIGHT...CAUSING WINDS TO SHIFT FROM THE NW.

NORTH WINDS ARE FORECAST TO INCREASE TO ARND 20 KT FRI MORNING AS
LOW PRES MOVES OFFSHORE.

A SCA MAY BE NEEDED ON THE OCEAN WATERS FRI INTO FRI EVE FOR
WINDS AND SEAS DUE TO A MODEST NLY FLOW WITH LOW PRES PASSING TO
THE E. TRANQUIL CONDS THEN PREVAIL ON ALL WATERS THROUGH SUN. AN
SCA MAY BE NEEDED AGAIN SUN NIGHT THROUGH MON ON AT LEAST THE
OCEAN AS A COASTAL STORM PASSES WELL S AND E OF THE AREA. ALTHOUGH
THERE IS SOME UNCERTAINTY WITH THE TRACK OF THIS STORM...SEAS
SHOULD STILL BUILD TO AT LEAST 5 FT. HAVE LOWER CONFIDENCE IN THE
WIND FORECAST.

&&

.HYDROLOGY...
THROUGH TONIGHT...STORM TOTAL RAINFALL FORECASTS AREA WIDE REMAIN
1-1.5 INCHES WITH MINOR URBAN FLOODING OF LOW LYING POOR DRAINAGE
AREAS WITH MAXIMUM ESTIMATED HOURLY RATES OF 1/4 TO 1/2 INCH.

THERE IS A SLIGHT CHANCE...LESS THAN 20 PERCENT CHANCE...OF FLASH
FLOODING...MEANING THIS IS AN ISOLATED THREAT.

THURSDAY NIGHT-FRIDAY...1-2 INCHES OF SNOW LIKELY FOR LONG ISLAND
AND SE CT. LOW CHC OF 3-6 INCH SNOW FOR THIS SAME AREA.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-335-
     338-340-345.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355.

&&

$$
SYNOPSIS...GC
NEAR TERM...GC/MPS
SHORT TERM...GC
LONG TERM...24
AVIATION...PW
MARINE...GC/24/MPS
HYDROLOGY...GC/24



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