Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 292345
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
745 PM EDT SAT AUG 29 2015

.SYNOPSIS...
HIGH PRESSURE SLIDES OFFSHORE AND MERGES WITH THE BERMUDA HIGH
INTO SUNDAY. A TROUGH OF LOW PRESSURE CROSSES THE AREA LATE
SUNDAY...AS THE BERMUDA HIGH REMAINS OFFSHORE INTO EARLY NEXT
WEEK. A BACK DOOR COLD FRONT MOVES INTO THE WATERS ON
TUESDAY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY WEDNESDAY.
HIGH PRESSURE THEN REMAINS IN CONTROL THROUGH THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
A NORTHERN STREAM SHORTWAVE PASSES TO THE NORTH INTO THE
OVERNIGHT HOURS...FOLLOWED BY WEAK NORTHERN STREAM RIDGING
BUILDING IN LATE TONIGHT INTO FAR W ZONES. GIVEN THAT THE BEST
FORCING WILL BE CONFINED TO NEAR THE U.S.-CANADIAN BORDER...EXPECT
MAINLY HIGH AND SOME MID CLOUDS WITH THE PASSAGE OF THE
SHORTWAVE...LIMITED TO MAINLY NW ZONES.

FORECAST IS GENERALLY ON TRACK. MADE SOME ADJUSTMENTS TO CLOUD
COVER OVERNIGHT AS MOST OF THE AREA SHOULD BE PARTLY CLOUDY.
OTHERWISE...MINOR CHANGES TO T/TD/WINDS TO BETTER REFLECT CURRENT
CONDS AND TRENDS.

FOR LOWS TONIGHT USED A BLEND OF MAV/MET/ECS GUIDANCE...WITH NAM
2-METER TEMPERATURES MIXED IN OVER URBAN AREAS. LOWS SHOULD BE A
FEW DEGREES ABOVE NORMAL.

&&

.SHORT TERM /SUNDAY NIGHT/...
THE AFOREMENTIONED SHORTWAVE RIDGING EXITS TO THE EAST BY EARLY
AFTERNOON...FOLLOWED BY A NORTHERN STREAM TROUGH WHICH THEN
CROSSES THE AREA SUNDAY AFTERNOON AND NIGHT. IT SHOULD BE NOTED
THAT THE ECMWF IS A SLOW OUTLIER WITH THE TIMING OF THE
TROUGH...SO USED A NON-ECMWF SOLUTION FOR SUNDAY AND SUNDAY NIGHT.

NOTING THE GFS/CMC-REG/NAM/SREF ALL INDICATE SOME SHOWERS ACROSS
MAINLY N INTERIOR ZONES MAINLY SUNDAY AFTERNOON INTO SUNDAY
EVENING...HAVE INTRODUCED SLIGHT CHANCE POPS FROM ROUGHLY ORANGE
COUNTY/WESTERN NE NJ ON NE INTO N MIDDLESEX COUNTY. APPEARS THAT
SHOULD HAVE SUFFICIENT LOW LEVEL CAPE AND LOW LEVEL
INSTABILITY...WITH SHOWALTER INDICES DOWN TO BELOW 3...TO WARRANT
A SLIGHT CHANCE OF THUNDER AS WELL.

TEMPERATURES ON SUNDAY WILL BE A FUNCTION OF HOW MUCH CLOUD COVER
THERE IS AHEAD OF THE TROUGH. WITH MODELS HAVING 1000-500 RH OVER
70% OVER MOST OF THE AREA...HAVE INCREASED CLOUD COVER.
HOWEVER...LOW LEVELS COULD BE SUFFICIENTLY DRY TO SUPPORT MIXING
TO UP TO 850-825 HPA PER BUFKIT SOUNDINGS...EVEN WITH CLOUD COVER.
SO FOR NOW FORECASTING HIGHS 5-10 DEGREES ABOVE NORMAL...WITH SOME
READINGS AROUND 90 IN URBAN NE NJ AND POSSIBLY NYC. THIS
CONSISTENT WITH BLENDING A MIX DOWN FROM 950-825 HPA PER BUFKIT
SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MET/ECS/MAV GUIDANCE. WITH THE RELATIVELY DRY LOW LEVELS...HEAT
INDICES ON SUNDAY AFTERNOON SHOULD PEAK OUT IN THE UPPER 80S IN
URBAN AREAS...WHICH IS A FEW DEGREES BELOW THE FORECAST AIR
TEMPERATURE.

FOR LOWS SUNDAY NIGHT...USED A BLEND OF MAV/ECS/MET GUIDANCE AND
NAM 2-METER TEMPERATURES WITH VALUES FORECAST TO BE AROUND 5-10
DEGREES ABOVE NORMAL.

THERE IS A MODERATE RISK FOR THE DEVELOPMENT OF RIP CURRENTS ON
SUNDAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
THE MAIN THEME OF THE LONG TERM PERIOD WILL BE THE CONTINUATION OF
HEAT AND HUMIDITY ACROSS THE REGION.

MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN ACROSS NORTH
AMERICA INTO THE MIDDLE OF THE WEEK. AN UPPER LEVEL TROUGH WILL
SLIDE THROUGH THE AREA ON MON BRINGING A WEAK BACK DOOR COLD FRONT
INTO THE AREA. THERE WON`T BE MUCH RELIEF FROM THE HEAT AND
HUMIDITY AS THE BOUNDARY WILL LIFT BACK TO THE N AS A WARM FRONT
BY WED. AN UPPER LEVEL RIDGE MOVING THROUGH EASTERN CANADA WILL
THEN MERGE WITH THE BERMUDA HIGH OVER THE ATLANTIC PROVIDING DRY
AND UNSEASONABLY WARM WEATHER THROUGH THU POSSIBLY FRI. THIS WILL
DEPEND ON THE TIMING OF THE NEXT COLD FRONT MOVING ACROSS WHICH IS
CURRENTLY UNCERTAIN DUE TO DIFFERENCES THAT DEVELOP IN THE H5 FLOW
DURING THE LATTER PORTION OF THE WEEK. COULD SEE A FEW SHOWERS OR
TSTMS WITH THE FRONTAL PASSAGE WHICH IS CURRENTLY SLATED FOR
FRIDAY...FOLLOWED BY DRY CONDITIONS AND COOLER BUT STILL ABOVE
NORMAL TEMPS FOR THE WEEKEND.

HIGHS WILL GENERALLY RANGE IN THE UPPER 80S TO LOWER 90S ACROSS THE
AREA THROUGH MUCH OF THE WEEK...THE EXCEPTION BEING TUE AND FRI/SAT
WITH THE FRONTAL BOUNDARIES IN/THROUGH THE AREA. HEAT INDICES ARE
EXPECTED TO BE CLOSE TO THE AMBIENT AIR TEMP AND ARE NOT CURRENTLY
EXPECTED TO REACH 95 DEGREES IN NYC THROUGH WED.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE SLIDES OFFSHORE. A TROUGH OF LOW PRESSURE CROSSES THE
AREA LATE SUNDAY.

VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. INCREASING MID
CLOUDS ARE ANTICIPATED SUNDAY...WITH FEW CLOUDS TONIGHT. AN ISOLATED
SHOWER OR THUNDERSTORM CANNOT BE RULED OUT...MAINLY NW OF NYC
TERMINALS DURING THE AFTERNOON.

SEA BREEZE WEAKENS EARLY THIS EVENING...AS WINDS OVERALL DIMINISH TO
UNDER 10 KT. WIND DIRECTION WILL BE S-SW.

A W/SW FLOW 5 TO 10 KT IS FORECAST SUNDAY MORNING. THEN SEA BREEZES
ARE LIKELY DURING THE AFTERNOON. SPEEDS INCREASE AND A FEW GUSTS IN
THE 15 TO 20 KT RANGE ARE POSSIBLE. COASTAL TERMINALS WILL LIKELY
OBSERVE STRONGER WINDS IN THE 15 TO 20 KT RANGE.

.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.SUNDAY NIGHT-THURSDAY...VFR. AFTERNOON SEABREEZES AT COASTAL
TERMINALS EACH DAY. SW GUSTS AROUND 15 KT NEAR CITY TERMINALS MONDAY
AFTERNOON.

&&

.MARINE...
A RELATIVELY RELAXED PRESSURE GRADIENT OVER THE REGION WILL KEEP
SUSTAINED WINDS TO 15 KT OR LESS AND GUSTS TO 20 KT OR LESS
THROUGH SUNDAY NIGHT. AS A RESULT...ABSENT ANY SIGNIFICANT
SWELL...SEAS ON THE COASTAL OCEAN WATERS WILL BE 4 FT OR LESS AND
SEAS/WAVES ON THE SOUND/HARBOR/BAYS 2 FT OR LESS THROUGH SUNDAY
NIGHT AS WELL.

MARGINAL SCA LEVEL SEAS MAY CLIP THE OUTERMOST PORTION OF ANZ350
ON MON...OTHERWISE SUB-SMALL CRAFT ADVISORY CONDITIONS ARE
EXPECTED ON ALL WATERS MONDAY THROUGH THURSDAY.

&&

.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED FOR THE REMAINDER OF THIS
WEEKEND AND FOR THE UPCOMING WORK WEEK.

&&

.TIDES/COASTAL FLOODING...
WITH A RECENT FULL MOON...BRIEF MINOR INUNDATION IS POSSIBLE
DURING THE TIMES OF HIGH TIDE ACROSS THE TYPICALLY VULNERABLE
COASTAL LOCALES INTO THE START OF THE WORK WEEK.

&&

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

&&

$$


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