Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 310609
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
209 AM EDT SUN AUG 31 2014

.SYNOPSIS...
HIGH PRESSURE MOVES WELL TO THE EAST THROUGH SUNDAY. LOW PRESSURE
TRACKS ACROSS THE GREAT LAKES AND INTO EASTERN CANADA...SENDING A
LOW PRESSURE TROUGH ACROSS THE AREA LATE SUNDAY. THIS TROUGH WEAKENS
AND EVENTUALLY DISSIPATES WITHIN THE REGION ON MONDAY. THIS WILL
LEAVE BEHIND A WEAK PRESSURE GRADIENT. A COLD FRONT MOVES THROUGH
TUESDAY NIGHT WITH HIGH PRESSURE THEN BUILDING IN FROM THE SOUTH
AND WEST THROUGH THURSDAY. THE HIGH MOVES OFFSHORE FRIDAY WITH
ANOTHER COLD FRONT APPROACHING INTO THE BEGINNING OF NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ALOFT...LARGE RIDGE REMAINS ANCHORED SOUTHEAST OF THE REGION AS A
TROUGH MOVES ACROSS THE GREAT LAKES REGION TONIGHT.

SFC HIGH PRESSURE SITS SOUTHEAST OF THE REGION TONIGHT.

PLENTY OF CLOUDS...WARM AND INCREASINGLY MUGGY CONDITIONS ARE
FORECAST OVERNIGHT. DEW POINT INCREASE PER MOS AS SOUTH FLOW
PERSISTS. LOW TEMPS IN THE 60S PER MOS BLEND FOLLOWED.

HIGH RES MODELS SIGNALING POTENTIAL LATE TONIGHT INTO EARLY
SUNDAY MORNING FOR AN ISOLATED SHOWER WITH THETA-E ADVECTION AND A
WEAK VORT MOVING THROUGH.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP SOUTHWEST FLOW THROUGH THIS TIME FRAME AS SHORTWAVE MOVES WELL
TO THE NORTH...WITH RIDGE ANCHORED OVER THE WESTERN ATLANTIC.

WARM AND MUGGY CONDITIONS WILL PREVAIL. PLENTY OF CLOUDS
EXPECTED...ALONG WITH AN INCREASING CHANCE FOR SHOWERS/TSTMS.

MODERATE INSTABILITY IS EXPECTED BY AFTERNOON SUNDAY...AND
PRECIPITABLE WATERS INCREASE TO 2 INCHES...OR CLOSE TO 200
PERCENT ABOVE NORMAL LATE IN THE DAY AND INTO THE EVENING.

MARGINAL TO MODERATE SHEAR IS PRESENT...WITH KI RIGHT AROUND 35C.
EXPECT SCATTERED TO NUMEROUS...ALTHOUGH WILL KEEP PROBABILITY
WORDING...SHOWERS AND TSTMS. SOME OF WHICH WILL PRODUCE HEAVY
DOWNPOURS. BEST TIMING IS LATE AFTERNOON WESTERN ZONES...AND THROUGH
THE EVENING/OVERNIGHT CSTL AND ERN ZONES.

MODELS CONTINUE TO VARY WITH REGARD TO HEAVIER SHOWER/TSTM
LOCATION...DUE TO THE SCATTERED NATURE OF THE ACTIVITY AND VARYING
PLACEMENTS OF EMBEDDED MID LEVEL SHORTWAVES. SFC TROUGH APPROACHING
TO THE WEST SHOULD TRIGGER ACTIVITY.

AFTER COLLAB WITH SURROUNDING OFFICES...WILL NOT ISSUE A FLASH FLOOD
WATCH AT THIS TIME. THE THREAT WILL BE URBAN...WITH PERHAPS FLASHIER
STREAMS SUSCEPTIBLE TO FLASH FLOODING. OTHERWISE...COUNTY GUIDANCE
LIKELY TOO HIGH OUTSIDE OF METRO.

WARM TEMPS IN THE 80S SUNDAY...WITH WARM UPPER 60S TO 70S SUNDAY
NIGHT LOWS. FOLLOWED A MOS BLEND...WHICH INCLUDED ECS NUMBERS.

A MODERATE RISK OF RIP CURRENTS IS EXPECTED FOR THE FIRST HALF OF
THE DAY SUNDAY...BUT THIS MAY INCREASE TO HIGH BY LATE IN THE DAY
WITH INCREASING SOUTHERLY WINDS AND RESULTANT WINDS
WAVES...INTERACTING WITH A BACKGROUND LONG PERIOD SE SWELL.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE DOMINANT PATTERN IN THE LONG TERM IS THAT OF RIDGING ON AVERAGE.
ON A LARGE SCALE...AN UPPER LEVEL RIDGE IS APPARENT ON THE MODEL
HEIGHT FIELDS ALOFT FROM QUEBEC TO THE MID-ATLANTIC. A RELATIVELY
STRONGER UPPER LEVEL TROUGH PASSES NORTH OF THE REGION LATE
TUESDAY INTO EARLY WEDNESDAY WITH SOME MORE HEIGHT FALLS AND A
TRANSITION TO ZONAL FLOW. RIDGING RESUMES THEREAFTER WITH THE
LARGE RIDGE ACROSS THE SOUTHERN U.S. PUSHING NORTH FROM WEDNESDAY
THROUGH FRIDAY.

AT THE SURFACE...A SURFACE TROUGH MOVING IN FROM THE WEST
DISSIPATES WITHIN THE REGION WITHOUT MUCH UPPER LEVEL SUPPORT ON
MONDAY. A WEAK PRESSURE GRADIENT IS LEFT IN ITS PLACE WITHOUT A
STRONG PRESENCE OF HIGH PRESSURE. THE JET STREAM WILL BE LIFTING
NORTH AWAY FROM THE REGION HELPING EXPLAIN THE LACK OF SUPPORT
ALOFT. THE JET PUSHES BACK SOUTH TUESDAY NIGHT INTO EARLY
WEDNESDAY...SO THIS WILL HELP PUSH A COLD FRONT THROUGH THE
REGION. THIS WILL TRANSITION WINDS TO MORE OF A NORTHERLY FLOW FOR
WEDNESDAY. THE FLOW WEAKENS THURSDAY...ALLOWING FOR SEA BREEZES
TO DEVELOP AS HIGH PRESSURE BUILDS IN FROM THE SOUTH AND WEST. THE
HIGH MOVES OFFSHORE FRIDAY INTO THE NEXT WEEKEND. ANOTHER COLD FRONT
APPROACHES INTO THE BEGINNING OF NEXT WEEKEND.

OUTSIDE OF WEDNESDAY...A GENERAL SOUTH TO SOUTHWEST FLOW DOMINATES
NEXT WEEK. THIS WILL RESULT IN TEMPERATURES WELL ABOVE SEASONAL
AVERAGES FOR THIS TIME OF YEAR. THE JET STREAM OVERALL KEEPS TO THE
NORTH OF THE REGION. TEMPERATURES WILL BE GENERALLY 5-10 DEGREES
ABOVE NORMAL MONDAY THROUGH WEDNESDAY AND A FEW DEGREES ABOVE
NORMAL WEDNESDAY NIGHT THROUGH SATURDAY.

IN TERMS OF WEATHER...HIGHEST CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE ON MONDAY WITH THE INSTABILITY AND REMNANT
FRONTAL BOUNDARY ACROSS THE REGION. CHANCES DECREASING BY LATE IN
THE DAY AND INTO MONDAY NIGHT. ESTIMATING THESE TO BE MORE OF THE
PULSE VARIETY WITH THE LACK OF UPPER LEVEL SUPPORT. BULK SHEAR
0-6KM MOSTLY 20-25 KT WITH CAPE BEING THE GREATER DRIVER FOR
CONVECTION. ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS FROM
NORTHWEST TO SOUTHEAST TUESDAY INTO TUESDAY NIGHT WITH A LITTLE
MORE SHEAR TO WORK WITH. MAINLY DRY THEREAFTER WITH A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS TOWARDS END OF THE WORK WEEK
INTO THE NEXT WEEKEND WITH NEXT FRONT APPROACHING.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
HIGH PRES OVER THE WESTERN ATLANTIC WILL CONTINUE TO DEPART OVERNIGHT
AS A TROUGH OF LOW PRES APPROACHES FROM THE WEST LATE SUNDAY.

VFR CIGS TO START GRADUALLY LOWER THROUGH THE OVERNIGHT...WITH LOW
MVFR/LOCALLY IFR CIGS LIKELY LATE TONIGHT/SUN AM. HEATING SHOULD
RAISE CIGS TO VFR IN THE LATE MORNING/EARLY AFTN.

ISOLATED SHRA/TSRA POSSIBLE ALONG SEABREEZE BOUNDARIES SUN
AFTERNOON. OTHERWISE...INCREASING CHANCE FOR SHRA/TSTMS LATE
AFTN/EVE MAINLY FROM CITY TERMINALS AND POINTS N/W AS TROUGH
APPROACHES. TIMING MAY NEED TO BE ADJUSTED A FEW HOURS.

.OUTLOOK FOR 06Z MON THROUGH THU...
.SUN NIGHT-MON...NUMEROUS SHRA/EMBEDDED TSTMS AND OCNL MVFR
TRANSLATING EASTWARD ACROSS TERMINALS SUN NIGHT THROUGH MON
MORNING. ADDITIONAL SCT SHRA/TSRA POSSIBLE MON AFT/EVE. MVFR
STATUS/FOG POSSIBLE LATE MON NIGHT.
.TUE...SCT AFT/EVE SHRA/TSRA POSSIBLE.
.WED-THU...MAINLY VFR.

&&

.MARINE...
SOUTHERLY WINDS PERSISTS TONIGHT AS HIGH PRESSURE DRIFTS FURTHER TO
THE EAST.

THE SOUTHERLY WINDS INCREASE AHEAD OF A SURFACE TROUGH LATER SUNDAY
INTO SUNDAY EVENING. EXPECT WINDS TO REMAIN JUST BELOW 25 KTS ON
THE WATERS...SO WILL NOT ISSUE A SCA AT THIS TIME PER SURROUNDING
OFFICE COLLAB. SEAS BUILD IN RESPONSE TO THESE INCREASING
WINDS...AND MAY COME CLOSE TO 5 FEET OVER THE OCEAN WATERS LATE
SUNDAY AND INTO SUNDAY NIGHT.

OVERALL...THE PRESSURE GRADIENT REMAINS WEAK IN THE LONG TERM PERIOD
OF MONDAY THROUGH THURSDAY. SEAS WILL BE ON A DOWNWARD TREND EARLY
MONDAY WITH A COLD FRONT DISSIPATING WITHIN THE REGION. CONDITIONS
ARE EXPECTED TO REMAIN BELOW SCA ON THE WATERS THROUGH THE LONG TERM
PERIOD.

&&

.HYDROLOGY...
DEEP MOISTURE IN PLACE WITH TROF APPROACHING SUNDAY AND INTO THE
REGION SUNDAY NIGHT...SO ANY SHOWERS AND THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING LOCALLY HEAVY DOWNPOURS. LOCALIZED FLOODING
THREAT WILL REMAIN WHICH WOULD VARY FROM MINOR AND POOR DRAINAGE
TO POSSIBLY FLASH FLOODING.

HEAVY RAIN POTENTIAL WITH ANY SHOWERS OR THUNDERSTORMS WILL REMAIN
AS PRECIPITABLE WATERS REMAIN AROUND 2 INCHES MONDAY. THIS WILL POSE
A FLOODING THREAT VARYING FROM POSSIBLE MINOR AND POOR DRAINAGE
FLOODING TO SOME POSSIBLE FLASH FLOODING.

&&

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

&&

$$
S




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