Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 262349
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
749 PM EDT SUN JUL 26 2015

.SYNOPSIS...
A WEAKENING COLD FRONT APPROACHES FROM THE WEST THIS EVENING AND
DISSIPATES NEAR OR JUST WEST OF THE HUDSON RIVER LATE TONIGHT. A
WEAK TROUGH WILL REMAIN ACROSS THE AREA ON MONDAY. HIGH PRESSURE
WILL BUILD IN FOR THE MID WEEK...PASSING TO THE SOUTH. A COLD
FRONT APPROACHES THURSDAY...CROSSING THE AREA THURSDAY AFTERNOON
AND EVENING. WEAK HIGH PRESSURE BUILDS IN FRIDAY...THEN SLIDES
OFFSHORE ON SATURDAY. A WEAK FRONTAL BOUNDARY APPROACHES SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AXIS OF INSTABILITY IS WANING LATE THIS EVENING. AN APPROACHING
WEAK COLD FRONT WILL RESULT IN SCT CONVECTION THROUGH THE
NIGHT...PROGRESSING EAST FROM THE LOWER HUDSON VALLEY AND NE NJ.
A LACK OF DEEP-LAYERED SHEAR HAS SUPPORTED SHORT-LIVED CELLS WITH
HEAVY RAINFALL...SMALL HAIL...AND GUSTY WINDS. MOST OF THIS
ACTIVITY HAS BEEN TO THE NW OF THE REGION.

A MODERATE SLY FLOW WILL GUST UP TO 20 MPH THIS EVENING BEFORE
THE COASTAL JET WEAKENS. LOWS WILL RANGE FROM THE MID 60S INLAND
TO AROUND 70 AT THE COAST. DEW POINTS WILL BE WELL INTO THE 60S
MAKING IT QUITE HUMID AS WELL.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
A MID LEVEL SHORT WAVE TROF EXITS OFF THE COAST IN THE LATE
MORNING/EARLY AFTERNOON HOURS WITH SHORT WAVE RIDGING TO FOLLOW.
THIS COULD PUT A LID ON THE CONVECTION FOR THE REMAINDER OF MON.
A THERMAL TROF ACROSS THE AREA WITH MDT-HIGH INSTABILITY...BUT
ONCE AGAIN WEAK SHEAR...WILL RESULT IN SCT CONVECTION FOR THE
FIRST HALF OF THE DAY...WHICH THEN DISSIPATES BY EVE. HIGH
PRESSURE BUILDS EAST FROM THE OHIO VALLEY MON NIGHT.

PREFERENCE WAS TO GO WITH MET MOS HIGHS ON MON...WHICH ARE
WARMER...IN THE MID TO UPPER 80S. THE GFS APPEARS TOO WET AND THUS
THE COOLER TEMPS. MON NIGHT WILL BE ANOTHER WARM MUGGY NIGHT WITH
LOWS IN THE MID 60S TO THE LOWER 70S.

THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF
RIP CURRENT FORMATION AT ATLANTIC BEACHES MONDAY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
ON TUESDAY...UPPER TROUGH SLOWLY DEPARTS TO THE EAST AS LARGE RIDGE
BUILDS. 12Z MODEL SUITE SHOWS PVA MOVING ACROSS THE NORTHEAST FROM
NW TO SE THROUGH THE DAY TUESDAY...WITH LINGERING SFC TROUGH NEARBY.
THIS VORT PLACEMENT DOES DIFFER SOMEWHAT PER MODEL...BUT CANNOT RULE
OUT A STRAY SHOWER OR TSTM EASTERN ZONES DURING THE DAY TUESDAY AS
ANY LIFT IN CONJUNCTION WITH WEAK INSTABILITY COULD TRIGGER
SOMETHING. BEST COVERAGE THOUGH WILL BE OVER NEW ENGLAND.

THEN AS RIDGE BUILDS AND SUBSIDENCE ENSUES...DRY WEATHER CAN BE
EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

UPPER LEVEL RIDGE EVENTUALLY SETTLES ACROSS THE SOUTHERN STATES...AS
THE WESTERLIES BEGIN TO SAG ACROSS THE GREAT LAKES STATES...WITH
LOWERING HEIGHTS FORECAST OVER THE NORTHEAST THURSDAY. THIS WILL
RESULT IN A WEAKENING COLD FRONT THAT IS PROGGED TO MOVE THROUGH
SOMETIME LATE THURSDAY.

IT DOES APPEAR THAT THIS FRONT WILL PASS FAR ENOUGH TO THE EAST
DURING THE LATTER PORTION OF THE WEEK. AS SUCH...HIGH PRESSURE
BUILDS IN.

NEXT WEAK FRONTAL BOUNDARY APPROACHES SUNDAY AS WEAK TROUGH SETTLES
ACROSS THE NORTHERN AND NORTHEASTERN STATES ALOFT.

AS FOR SENSIBLE WEATHER WED THROUGH SUNDAY...BEST CHANCE FOR
CONVECTION CONTINUES TO BE LATER THURSDAY AHEAD OF THE FRONT. ANY
LIFT ALOFT IS WEAK...BUT MARGINAL TO PERHAPS MODERATE CAPE WILL BE
AVAILABLE POTENTIALLY...AND A SLIGHTLY COOLER AND DRIER AIRMASS
MOVING EAST INTO THE HOT AND HUMID AIR MAY BE ENOUGH TO PRODUCE A
FEW SHOWERS AND TSTMS.

DRY FRIDAY THROUGH SUNDAY...ALTHOUGH A FEW STRAY SHOWERS AND TSTMS
CANNOT BE RULED OUT SUNDAY AHEAD OF THE TROUGH.

TEMPS BEGIN TO WARM TUESDAY...WITH A MOS BLEND USED FOR FCST HIGH/S.
EXPECT READINGS IN THE 80S...APPROACHING OR TOUCHING 90 IN AND
AROUND NYC METRO. DEW POINTS MAY MIX OUT SOMEWHAT PER MOS AND
POSSIBLE WEST TO SW FLOW. AS SUCH...HEAT INDICES MAY FALL SHORT OF
THE MID 90S IN AND AROUND NYC.

ON WEDNESDAY...THE HEAT BUILDS WITH 90S EXPECTED ACROSS THE CWA
AFTER A VERY WARM START TO THE DAY. MORNING LOWS WILL BE IN THE
70S...EXCEPT SOME 60S ACROSS THE INTERIOR. HEAT INDICES LIKELY REACH
THE MID TO UPPER 90S.

TEMPS REMAIN QUITE WARM TO HOT THROUGH THURSDAY...WITH 70S AT NIGHT
AND UPPER 80S TO LOWER 90S DURING THE DAY. A SLIGHT COOL DOWN BEHIND
THE FRONT IS EXPECTED THURSDAY NIGHT THROUGH SUNDAY...BUT IT WILL
REMAIN QUITE WARM TO HOT WITH TEMPS AVERAGING ABOVE NORMAL BY ABOUT
5 DEGREES. USED A WPC AND GRIDDED MOS BLEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
LOW CONFIDENCE FORECAST TONIGHT THROUGH MONDAY AS A WEAKENING
COLD FRONT MOVES ACROSS THE LOCAL AIRSPACE TONIGHT...AND THEN
DISSIPATES JUST SOUTH OF LONG ISLAND MONDAY MORNING.

SCATTERED SHRA/TSRA LIKELY AT SOME POINT LATE TONIGHT THROUGH
MONDAY MORNING. CURRENT THINKING HAS BEST TIMING FROM 07-11Z NORTH
AND WEST OF KNYC TERMINALS...AND FROM 08-12Z FOR KJFK/KLGA. BASED
ON LATEST SHORT RANGE GUIDANCE...DO NOT THINK STORMS WILL HOLD
TOGETHER BEFORE REACHING KBDR/KISP/KGON AT THIS TIME...AND WILL
NOT MENTION IN TAFS. FOR THE REST OF THE TAFS...WILL USE TEMPO
GROUPS TO CONVEY TIMING OF CONVECTION.

THERE ARE STRONG TSRA WEST OF KSWF...AND SOME OF THOSE STORMS
COULD IMPACT KSWF EARLY THIS EVENING. WILL TEMPO FROM
00-04Z...BUT VCTS MAY BE A BETTER DESCRIPTION OF WHAT WILL HAPPEN
THERE.

S/SW WINDS WILL DIMINISH TO 5 KT OR LESS THIS EVENING...AND THEN
SOUTH WINDS WILL INCREASE TO 5-10 KT LATE MONDAY MORNING WITH
LOCALLY STRONGER WINDS AT COASTAL TERMINALS DUE TO AFTERNOON SEA
BREEZES.

.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.MONDAY NIGHT...VFR.
.TUESDAY-THURSDAY...MAINLY VFR. 5-6SM HAZE DEVELOPMENT POSSIBLE.
SW WINDS WITH AFTERNOON SEABREEZE DEVELOPMENT AT COASTAL
TERMINALS. THUNDER IS POSSIBLE THURSDAY AFTERNOON.
.FRIDAY...VFR.

&&

.MARINE...
WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT LEVELS
THROUGH TONIGHT. SCA GUSTS HAVE OCCURRED ACROSS THE NY BIGHT AND
SURROUNDING NEARSHORE WATERS DUE TO COASTAL JET. OCEAN SEAS
HAVE BUILT TO AROUND 4 FT. AS THE NIGHT PROGRESSES...WINDS WILL
ABATE.

SUB SCA CONDITIONS WITH A FAIRLY WEAK PRESSURE GRADIENT MON
INTO MON NIGHT.

A WEAK TROUGH TUESDAY MOVES EAST AS HIGH PRESSURE BUILDS WEDNESDAY.
WINDS AND THUS SEAS SHOULD REMAIN FAIRLY TRANQUIL DURING THIS TIME.

THE PRESSURE GRADIENT TIGHTENS SOMEWHAT THURSDAY AHEAD OF A
WEAKENING COLD FRONT. WINDS INCREASE...BUT SHOULD REMAIN BELOW SCA
THRESHOLDS. HOWEVER...OCEAN SEAS LIKELY BUILD CLOSE TO 5 FEET. WAVE
WATCH REMAINS CONSISTENT IN FORECASTING THIS...BUT IT COULD BE
OVERDONE BY A FOOT OR SO.

WINDS DIMINISH BEHIND THE SLOW MOVING FRONT AS THE PRESSURE GRADIENT
WEAKENS. SEAS WILL SUBSIDE AS A RESULT.

&&

.HYDROLOGY...
NO WIDESPREAD SIGNIFICANT PRECIPITATION IS EXPECTED INTO THE
MIDDLE OF THE WEEK.

HOWEVER...ANY STRONGER STORMS THAT DUE HAPPEN TO FORM ON MONDAY
WILL BE VERY SLOW TO MOVE...WITH STORM MOTION FORECAST TO BE 10
KT OR LESS. AS A RESULT...THERE IS THE POTENTIAL FOR LOCALIZED
URBAN/POOR DRAINAGE FLOODING FROM MONDAY INTO MONDAY EVENING.

THERE IS ALSO THE POSSIBILITY FOR LOCALLY HEAVY RAINFALL WITH ANY
STRONGER STORMS THURSDAY AFTERNOON/EVENING...WHICH COULD ALSO
POSSIBLY CAUSE LOCAL URBAN/POOR DRAINAGE FLOODING.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HIGH RIP CURRENT RISK UNTIL 9 PM EDT THIS EVENING FOR NYZ075-
     080-081-178-179.
NJ...NONE.
MARINE...NONE.

&&

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



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