Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 302336
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
736 PM EDT SAT MAY 30 2015

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC THROUGH THIS
EVENING. A COLD FRONT APPROACHES TONIGHT...MOVES INTO THE REGION
SUNDAY...AND PUSHES SOUTH SUNDAY NIGHT. WAVES OF LOW PRESSURE
TRACK OVER OR JUST SOUTH OF THE AREA MONDAY INTO TUESDAY. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTH LATE TUESDAY INTO
WEDNESDAY...AND SHIFT TO THE SOUTH THURSDAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
FORECAST REMAINS ON TRACK. A FEW SHOWERS ARE MOVING INTO ORANGE
COUNTY...AND ALTHOUGH THERE MAY BE A BRIEF HEAVIER SHOWER...NOT
EXPECTING MUCH IN THE WAY OF CONVECTION. CONVECTION WILL CONTINUE
TO DISSIPATE THROUGH THIS EVENING WITH LOSS OF DIURNAL HEATING AND
WITH A STRONG MARINE LAYER WORKING NORTHWEST OF THE NYC/NJ METRO.

OTHERWISE...REGION WILL BE ON WESTERN PERIPHERY OF WESTERN
ATLANTIC RIDGING WITH DEEP TROUGH DIGGING INTO MISSISSIPPI AND
OHIO RIVER VALLEYS...AND A STRONG NORTHERN STREAM SHORTWAVE
TRACKING INTO QUEBEC TONIGHT.

AT THE SURFACE...AN ASSOCIATED SLOW MOVING COLD FRONT WILL
APPROACH THE REGION FROM THE WEST. THE NORTHERN STREAM SHORTWAVE
WILL PUSH THE NORTHERN PART OF THIS COLD FRONT INTO CENTRAL NY
TONIGHT. WEAK VORT ALOFT...LLJ FORCING...AND ELEVATED INSTABILITY
LATE TONIGHT COULD SUPPORT ISOLATED SHRA/TSRA ACTIVITY AHEAD OF
THE FRONT TONIGHT...BEST CHANCE N&W OF NYC METRO.

OTHERWISE...AN UNSEASONABLY WARM AND HUMID NIGHT WITH LOWS GENERALLY
IN THE 60S...NEAR 70 NYC/NJ METRO.

COASTAL STRATUS/DENSE FOG LIKELY ONCE AGAIN TONIGHT WITH MOIST
AIRMASS OVERRIDING THE COMPARABLY COOLER WATERS. SREF PROBS ARE
NOT THAT HIGH FOR TONIGHT...BUT MORE WIDESPREAD COVERAGE OF LOW
PROWS THAN WHAT IT WAS SHOWING FOR THIS MORNING.

A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC OCEAN BEACHES
CONTINUES THROUGH THIS EVENING.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
REGION WILL CONTINUE TO BE ON THE WESTERN PERIPHERY OF WESTERN
ATLANTIC RIDGING WITH DEEP TROUGH DIGGING INTO THE MISSISSIPPI AND
OHIO RIVER VALLEYS.

AT THE SURFACE...MODELS IN PRETTY GOOD AGREEMENT WITH A COLD FRONT
SINKING INTO NORTHERN PORTIONS OF THE REGION SUNDAY AFT/EVE IN THE
WAKE OF A STRONG NORTHERN STREAM SHORTWAVE SLIDING THROUGH QUEBEC.

THE COLD FRONT...A POSSIBLE WARM FRONT APPROACHING FROM THE SOUTH
ASSOCIATED WITH A WEAK SURFACE WAVE APPROACHING FROM THE WEST...AND
VORT ENERGY RIDING IN THE UPPER FLOW SHOULD ACT AS TRIGGER/FOCUSES
FOR NUMEROUS SHOWERS AND TSTMS DEVELOPING SUN AFT IN A MARGINALLY
UNSTABLE ENVIRONMENT ACROSS THE LOWER HUDSON VALLEY...SW CT AND
NE NJ...NYC METRO. MAIN THREAT APPEARS TO BE HEAVY DOWNPOURS AND
POTENTIAL FOR LOCALIZED URBAN FLASH FLOODING WITH ANY TRAINING
THUNDERSTORMS AS STEERING FLOW ALIGNS WITH THE FRONT AND PWATS
POOL TO 1.5 TO 2 INCHES AHEAD OF THE FRONT.

OVERALL SEVERE THREAT APPEARS TO BE SPARSE AND LOW...MAINLY ACROSS
NE NJ/LOWER HUD...AS INCREASING CLOUD COVER AND CONVECTIVE
ACTIVITY SHOULD TEMPER INSTABILITY IN AREAS OF INCREASING SHEAR
FARTHER NORTH. POTENTIAL FOR ROTATION IF ANY SEVERE STORMS DO
DEVELOP...WITH INCREASED LOW LEVEL SHEAR/HELICITY IN VICINITY
AHEAD OF THE SURFACE WAVE AND IN VICINITY OF FRONTAL BOUNDARIES.

MODELS COMING INTO BETTER AGREEMENT WITH COLD FRONT SINKING THROUGH
THE REGION SUNDAY NIGHT AS STRONG CANADIAN HIGH PRESSURE NOSES IN
FROM THE N/NE. WANING INSTABILITY SHOULD DECREASE COVERAGE AND
INTENSITY OF TSTMS IN THE EVENING. SHOWER AND ISOLATED EMBEDDED
TSTM THREAT IN THE VICINITY OF THE COLD FRONT AS IT PUSHES
THROUGH...LIKELY TRANSITIONING TO STRATIFORM IN ITS WAKE. HIGHEST
PROB FOR SHOWER AND EMBEDDED TSTM ACTIVITY IN THE EVENING AND RAIN
OVERNIGHT WILL BE ACROSS THE NYC/NJ METRO...SW CT AND LOWER HUD
VALLEY WITH LLJ FORCING TO THE NE OF THE SURFACE WAVE AND MORE IN
THE WAY OF VORT ENERGY...AND POSSIBLE SOME WEAK ELEVATED
INSTABILITY.

HIGHS ON SUNDAY WILL BE IN THE UPPER 70S TO LOWER 80S...WARMEST
ACROSS NE NJ. COOLER AND LESS MUGGY CANADIAN MARITIME AIRMASS
ADVECTS IN SUNDAY NIGHT.

THERE WILL BE A MODERATE RISK FOR RIP CURRENTS AT OCEAN FACING
BEACHES ON SUNDAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
FRONTAL BOUNDARY BECOMES NEARLY STATIONARY OVER OR JUST SOUTH OF
THE AREA EARLY THIS WEEK. SEVERAL AREAS OF LOW PRES WILL DEVELOP
OVER THE DELMARVA AREA AND TRACK TO THE NORTHEAST MONDAY THROUGH
TUESDAY. HIGH PRES BUILDS INTO THE REGION BEHIND THE FRONT
WEDNESDAY AND THURSDAY.

WILL CARRY LIKELY POPS FOR MONDAY AND MONDAY NIGHT...AND THEN LIKELY
POPS ON TUESDAY FOR THE EASTERN HALF OF THE CWA AS THE FINAL LOW
DEPARTS. COULD HAVE SOME EMBEDDED THUNDERSTORMS FROM TIME TO TIME
DURING THE DAY MONDAY AND TUESDAY.

HIGHS MONDAY AND TUESDAY WILL TOP OFF IN THE 60S TO AROUND 70...AND
THEN TEMPS WARM BACK UP THROUGH THE 70S FOR THE MID-WEEK PERIOD.

LOW PRES WILL IMPACT THE AREA LATE IN THE WEEK AND FOR THE FIRST
HALF OF THE WEEKEND. WILL CARRY CHANCE POPS FOR NOW.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE GIVES WAY TO A COLD FRONT LATE SUNDAY/SUNDAY NIGHT.

SOUTHERLY WINDS AND GUSTS SUBSIDE THIS EVENING. CANNOT RULE OUT A
SHOWER NEAR KSWF UNTIL AROUND 02Z.

EXPECT A RETURN OF LOW STRATUS AND FOG WITH IFR CONDS LATE TONIGHT
INTO MID MORNING SUNDAY. LIFR CONDS MAY BE POSSIBLE AT
KJFK/KISP/KBDR/KGON. SHOWERS AND A FEW TSTMS WITH MVFR AND LOCAL IFR
VSBYS ARE THEN POSSIBLE LATE SUNDAY MORNING INTO THE AFTN.

.OUTLOOK FOR 00Z SUNDAY THROUGH THU...
.SUNDAY NIGHT-TUE...CHANCE OF LOW STRATUS WITH IFR CIGS
DEVELOPING LATE EACH NIGHT AND MORNING. MVFR TO IFR CONDS ALSO
POSSIBLE AT TIMES IN SHOWERS/TSTMS.
.TUE NIGHT...BECOMING VFR.
.WED-THU...VFR.

&&

.MARINE...
WIND GUSTS OF 25 TO 30 KT EXPECTED ACROSS THE WESTERN OCEAN
WATERS...WESTERN LI SOUND...LOWER HARBOR...AND SOUTH SHORE BAYS OF
LI WITH A DEVELOPING COASTAL JET THIS EVENING. 4 TO 5 FT SEAS LIKELY
ON THE OCEAN WATERS INTO EVENING. SCA REMAINS IN EFFECT THROUGH
THIS EVENING FOR THESE LOCATIONS. ELSEWHERE WINDS AND SEAS REMAIN
JUST BELOW SMALL CRAFT LEVELS INTO TONIGHT.

DENSE FOG POSSIBLE ONCE AGAIN TONIGHT ACROSS OCEAN WATERS AND
SOUTHERN AND EASTERN NEARSHORE WATERS.

WITH A PROLONGED SOUTHERLY FLOW AHEAD OF AN APPROACHING COLD
FRONT...MARGINAL SCA SEAS POSSIBLE ON ALL OCEAN WATERS LATE TONIGHT
INTO SUNDAY NIGHT. CONFIDENCE NOT HIGH ENOUGH FOR AN SCA AT THIS
POINT WITH OBSERVED LONG PERIOD SE SWELLS RUNNING ABOUT 1 FT BELOW
WNA. WILL LET EVENING/OVERNIGHT SHIFT RE-EVAL.

SEAS ON THE OCEAN WATERS REMAIN AT OR ABOVE 5 FT FOR THE FIRST HALF
OF THE NEW WEEK...AND THEN SEAS WILL BEGIN TO SUBSIDE ON WEDNESDAY.

A PERSISTENT EASTERLY FLOW FOR THE START OF THE NEW WEEK COULD GUST
TO 25 KT FROM TIME TO TIME.

TRANQUIL CONDS RETURN FOR WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
BETWEEN 1/2 TO 1 1/2 INCHES OF RAIN LIKELY FOR MUCH OF NYC
METRO...NE NJ...LOWER HUD VALLEY...AND SOUTHERN CT SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT WITH SLOW MOVING COLD FRONT
APPROACHING. LOCALLY HIGHER AMOUNTS OF 2 TO 3 INCHES ARE POSSIBLE
WITH ANY TRAINING CONVECTION...WHICH WOULD POSE A FLASH FLOODING
THREAT. THE PROBABILITY IN ANY GIVEN LOCATION IS LOW. OF
NOTE...SBU WRF IS INDICATING POTENTIAL OF LOCALLY 3 TO 5 INCHES
DURING THIS 24 HR PERIOD.

RAINFALL AMOUNTS WILL TAPER DOWN TO 1/4 TO 1/2 INCH ACROSS EASTERN
LI AND SE CT...WITH MORE STABLE MARINE AIRMASS LIMITING CONVECTION.

AN ADDITIONAL 1 TO 2 INCHES OF RAIN POSSIBLE MONDAY THROUGH
TUESDAY. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE WITH ANY
THUNDERSTORM ACTIVITY. MINOR URBAN/POOR DRAINAGE/SMALL STREAM
FLOODING WOULD BE MOST LIKELY DURING THIS TIME.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ335-
     338-345-353-355.

&&

$$
SYNOPSIS...MPS/NV
NEAR TERM...MPS/NV
SHORT TERM...NV
LONG TERM...MPS
AVIATION...JC
MARINE...MPS/NV
HYDROLOGY...MPS/NV



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