Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 301959
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
359 PM EDT SUN AUG 30 2015

.SYNOPSIS...
A SURFACE TROUGH WILL MOVE INTO THE REGION TONIGHT AND MOVE SOUTH
OF LONG ISLAND MONDAY. A BACK DOOR COLD FRONT MOVES ACROSS LATE
MONDAY NIGHT. HIGH PRESSURE WILL KEEP HOT AND HUMID CONDITIONS
ACROSS THE REGION THROUGH MUCH OF THE WEEK. A WEAK COLD FRONT WILL
MOVE THROUGH THURSDAY NIGHT...BUT IT WILL STILL BE WARM AND MAINLY
DRY THROUGH NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
IN THE MID LEVELS...A SPLIT FOR OUR REGION WITH A WEAK HEIGHT
GRADIENT. A SHORTWAVE AND ASSOCIATED HIGHER PVA MOVE MOSTLY SOUTH OF
THE REGION AND ANOTHER STRONGER ONE MOVES WITHIN SOUTHEAST CANADA.
AT THE SURFACE...THERE WILL BE A WEAK SURFACE TROUGH MOVING TOWARDS
THE REGION. THIS WILL KEEP AN ABUNDANCE OF CLOUDS OVERHEAD FOR THE
NIGHT. THE LOWS WERE TAKEN FROM THE RELATIVELY WARMER SIDE OF
GUIDANCE OF THE MAV MOS...WITH VALUES EXPECTED TO BE WARMER THAN THE
PREVIOUS NIGHT WITH SOUTHWEST FLOW.

COOLING TEMPERATURES WITH COVERAGE OF ANY CONVECTION REMAINING
DECREASING INTO THIS EVENING. HOWEVER...THE ENVIRONMENT WILL
STILL BE SOMEWHAT UNSTABLE WITH SOME ELEVATED INSTABILITY AHEAD OF
THE SURFACE TROUGH. WITH THESE AFOREMENTIONED FACTORS...THERE WILL
BE A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS FOR TONIGHT
ACROSS ALL LOCATIONS.

THERE IS A CONTINUED MODERATE RISK FOR THE DEVELOPMENT OF RIP
CURRENTS INTO THIS EVENING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
THE SHORTWAVE WEAKENS SOUTH OF THE REGION MONDAY. A HIGH AMPLITUDE
RIDGE FROM THE WEST WILL BEGIN TO BUILD IN. HOWEVER...AT THE
SURFACE...THE TROUGH WILL REMAIN AND THE DAYTIME SHOULD ENHANCE IT
WITH THE SEA BREEZE GIVING SOME INCREASE IN THE TEMPERATURE GRADIENT
WITHIN THE REGION ACROSS THE COAST. THE COOLER TEMPS WILL BE
ADVECTED INTO THE REGION FROM THE MORE SOUTHERLY FLOW. THIS WILL
CONVERGE AGAINST PLACES THAT HAVE SOUTHWEST FLOW. THE POPS OVERALL
WILL NOT BE HIGH...JUST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
CLOSE TO THE COAST...BUT WITH THE AIRMASS BECOMING INCREASINGLY WARM
AND HUMID...INSTABILITY WILL BE LARGER AS CAPE INCREASES TO
APPROXIMATELY 500-1000 J/KG. INLAND...DRIER CONDITIONS SHOULD
PREVAIL. AN OVERALL VERY WARM DAY EXPECTED. A MAV/MET BLEND WAS USED
FOR HIGHS...YIELDING VALUES FROM THE MID 80S TO LOWER 90S ACROSS A
MAJORITY OF THE REGION.

ONCE THE HEATING WANES DOWN FOR MONDAY EVENING...THE ENVIRONMENT
WILL BECOME MORE STABLE AND THE HIGH AMPLITUDE RIDGE FROM THE WEST
WILL CONTINUE TO BUILD IN. THE SURFACE TROUGH WILL HAVE PUSHED SOUTH
OF LONG ISLAND. THERE WILL BE A WEAK BACK DOOR COLD FRONT MOVING
ACROSS LATE. OVERALL...THE GREATER INFLUENCE WILL BE FROM THE
RIDGE AND THE SUBSIDENCE FROM THE RIDGING WILL LEAD TO LESSENING
CLOUDS. HOWEVER...DESPITE LIGHT WINDS...LOWS WILL NOT CHANGE TOO
MUCH COMPARED TO THE PREVIOUS NIGHT. THE RELATIVELY WARM AND
HUMID AIRMASS WILL REMAIN THOUGH AS WARM AIR ADVECTION INCREASES
AT THE 850MB LEVEL.

&&

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

MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE H5 PATTERN ACROSS NOAM
THROUGH THE PERIOD. A LATE SEASON HEAT WAVE IS EXPECTED FOR PARTS OF
THE TRI-STATE AREA THIS WEEK AS A DEEP LAYERED RIDGE ENCOMPASSES THE
EASTERN US. A SLY FLOW FOR MUCH OF THE WEEK WILL KEEP HUMIDITY
LEVELS HIGH AS WELL. THE HOTTEST DAY...HEAT AND HUMIDITY COMBINED
LOOKS TO BE THURSDAY WITH MOISTURE POOLING AHEAD OF A WEAK COLD
FRONT. NOT EXPECTING HEAT ADVSY CRITERIA TO BE MET...ALTHOUGH HEAT
INDICES WILL RANGE BETWEEN THE UPPER 80S TO LOWER 90S EACH AFTERNOON
THROUGH WED WITH 90 TO 95 ON THU. ALTHOUGH PARTS OF NYC MAY REACH A
95 DEGREE HEAT INDEX THU...NOT EXPECTING IT FOR 2 CONSECUTIVE
DAYS. THEREFORE...NO ADVSY IS ANTICIPATED FOR THE CITY EITHER.

IT WILL BE A FAIRLY DRY WEEK WITH ONLY A FEW SHOWERS/TSTMS WITH THE
WEAK BOUNDARY THU/THU EVE AND AGAIN FRI/FRI EVE AS ANOTHER WEAK
BOUNDARY APPROACHES FROM THE N...THIS TIME WITH WEAK SHORTWAVE
ENERGY. THE FLOW BECOMES ELY FRI...BUT THE COMBINATION OF THE UPPER
ENERGY...LOW LEVEL CONVERGENCE AND THE OROGRAPHIC INFLUENCE COULD
TRIGGER A FEW SHOWERS/TSTMS.

THE ONSHORE FLOW WILL ALSO PROVIDE SOME RELIEF FROM THE HEAT
ESPECIALLY AT THE COAST FRI THROUGH SUN. TEMPS WILL STILL BE 5 TO 10
DEGREES ABOVE NORMAL THOUGH.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE TRI-STATE THIS
AFTERNOON AND EVENING...THEN STALL OUT SOUTH OF LONG ISLAND INTO
MONDAY.

VFR THROUGH THE TAF PERIOD.

SEABREEZES THROUGH ALL TERMINALS EXCEPT KSWF AND KHPN. ISOLATED
GUSTS TO AROUND 15-20 KT POSSIBLE AT NYC METRO TERMINALS LATE THIS
AFTERNOON AS WELL.

WINDS BECOME SW AT UNDER 10 KT AT CITY TERMINALS TONIGHT AND LIGHT
AND VARIABLE ELSEWHERE. WSW-WNW WINDS AT AROUND 10 KT DEVELOP BY
LATE MONDAY MORNING- EARLY MONDAY AFTERNOON. WIND SPEEDS COULD
INCREASE TO AROUND 15 KT AT KJFK TOWARDS THE END OF THE TAF
PERIOD.

AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT THE LOWER
HUDSON VALLEY THIS AFTERNOON/EARLY THIS EVENING. HAVE INCLUDED A
VCSH AT KSWF AND KHPN TO REFLECT.

.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON...VFR. WSW-W WINDS G15-20KT POSSIBLE.
.MONDAY NIGHT-WEDNESDAY NIGHT...VFR. AFTERNOON SEABREEZES PROBABLE
EACH AFTERNOON.
.THURSDAY...MOST LIKELY VFR. ISOLATED SHOWERS/THUNDERSTORMS
POSSIBLE. AFTERNOON SEABREEZES PROBABLE.
.THURSDAY NIGHT...VFR.
.FRIDAY...MOST LIKELY VFR. E WINDS G15-20KT POSSIBLE. ISOLATED-
SCATTERED SHOWERS/THUNDERSTORMS POSSIBLE.

&&

.MARINE...
INTO THIS EVENING...AMBROSE JET WILL HAVE SOME OCCASIONAL 25KT GUSTS
ACROSS THE WESTERN OCEAN WATERS. HOWEVER...THIS WILL NOT BE
SPATIALLY OR TEMPORALLY ENOUGH TO HAVE A SCA. THE REST OF THE SHORT
TERM THROUGH MONDAY NIGHT WILL HAVE A PRIMARILY WEAK PRESSURE
GRADIENT. THE WINDS WILL BE MAINLY LESS THAN 15 KT OUT OF THE
SOUTHWEST TO SOUTH. THERE COULD BE ANOTHER ROUND OF GUSTS MONDAY
AFTERNOON BUT THESE ARE EXPECTED TO BE UP TO 20 KT. SEAS ON THE
OCEAN MAY GET TO 5 FT MONDAY NIGHT. HOWEVER...WITH THE WEAK PRESSURE
GRADIENT...DID NOT THINK WINDS WOULD SUPPLY A STRONG ENOUGH FETCH TO
INCREASE SEAS TO 5 FT. THEREFORE CAPPED THE OCEAN SEAS AT 4 FT
MONDAY NIGHT.

SUB-ADVSY CONDS ARE EXPECTED ON ALL WATERS THROUGH THE
REMAINDER OF THE PERIOD.

&&

.HYDROLOGY...
ANY SHOWER OR THUNDERSTORM THROUGH MONDAY COULD RESULT IN A BRIEF
HEAVY DOWNPOUR...WITH PERHAPS A QUICK QUARTER OF AN INCH IN
RAINFALL AMOUNTS. THERE COULD BE SOME LOCALLY MINOR FLOODING BUT
CONFIDENCE IN THIS IS LOW WITH COVERAGE OF CONVECTION FORECAST
BEING LOW.

OVERALL...NO WIDESPREAD SIGNIFICANT RAINFALL IS FORECAST THROUGH
NEXT WEEKEND.

&&

.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.

&&

$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...MALOIT
MARINE...24/JM
HYDROLOGY...24/JM
TIDES/COASTAL FLOODING...


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