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000
FXUS61 KOKX 151756
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
156 PM EDT SAT JUN 15 2013

.SYNOPSIS...
HIGH PRESSURE SLIDES SOUTH AND EAST OF THE AREA THIS WEEKEND. A
SERIES OF WEAK FRONTS WILL IMPACT THE AREA SUNDAY INTO THE NEW
WEEK. HIGH PRESSURE RETURNS FOR THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FEW MINOR ADJUSTMENTS TO TEMPS. ALSO...SOME DAYTIME INSTABILITY
CU DEVELOPMENT NOTED IN OBS AND SAT IMAGERY. THE REGION IS CAPPED
AND LITTLE IF ANY VERTICAL DEVELOPMENT IS FORECAST.

HIGH PRESSURE ALOFT WITH SFC HIGH PRESSURE PASSING TO THE SOUTH
AND EAST OF THE AREA WILL PROVIDE SUNNY SKIES WITH NEAR OR JUST
ABOVE SEASONABLE TEMPS. TEMPS WILL TOP OUT IN THE UPPER 70S TO
LOWER 80S...WITH LATE AFTERNOON SEABREEZES KNOCKING TEMPS BACK
INTO THE MID TO UPPER 70S ALONG THE IMMEDIATE COAST.

THERE IS A MODERATE RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES
OF EASTERN LONG ISLAND.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
MODELS IN GENERAL AGREEMENT WITH AN ACTIVE NEAR ZONAL FLOW SUNDAY
INTO EARLY NEXT WEEK AS A PERSISTENT UPPER LOW SPINS OVER EASTERN
CANADA.

HIGH PRESSURE SLIDES OFFSHORE ON SUNDAY WITH A SERIES OF WEAK FRONTS
AFFECTING THE REGION LATE SUNDAY INTO TUESDAY.

IN THIS PATTERN EXACT TIMING OF SHORTWAVE ENERGY AND ASSOCIATED WEAK
FRONTS/WAVES IS DIFFICULT MORE THAN 24 HOURS OUT...BUT WILL
DETERMINE EXACT TIMING/LOCATION OF SHRA/TSRA ACTIVITY.

MODELS ARE PROGGING THE FIRST PIECE OF ENERGY...WHICH LOOKS TO BE A
COMBO OF A MIDWEST MCS AND SHORTWAVE ENERGY SHEARING FROM THE
CANADIAN PRAIRIES INTO ONTARIO/QUEBEC...TO TRACK A WEAK WAVE/FRONT
TOWARDS THE NORTHEAST FOR LATE SUNDAY. IF TIMING HOLDS...THIS WOULD
BRING A CHANCE FOR SHRA/TSRA TO THE REGION SUNDAY AFTERNOON/EVENING.
INSTABILITY APPEARS TO BE MARGINAL...BUT STRONG SHEAR COULD HAVE
ORGANIZED STRONG/MARGINALLY SEVERE TSRA ACTIVITY ACROSS CENTRAL
PA/NY SURVIVING INTO FAR W/NW/N SECTIONS OF THE REGION IN THE
AFTERNOON...THEN WEAKENING AS IT TRACKS EASTWARD IN THE EVENING.

MONDAY AFTERNOON/EVE COULD PRESENT THE NEXT CHANCE FOR SHRA/TSRA
ACTIVITY. MEDIUM RANGE GUIDANCE IS INDICATING THAT INSTABILITY
LEVELS SHOULD BE SLIGHTLY HIGHER ON MON WITH STILL STRONG DEEP LAYER
SHEAR...SUPPORTING POTENTIAL FOR SOME ORGANIZED STRONG TO SEVERE
STORMS IF SHORTWAVE/FRONTAL FORCING IS PRESENT. ULTIMATELY...EXTENT
OF SUN AFT/EVE CONVECTION AND TIMING OF SHORTWAVE ENERGY/FRONTAL
FORCING WILL DETERMINE HOW FAVORABLE THE ENVIRONMENT IS FOR
CONVECTION ON MONDAY.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A MID LEVEL TROUGH WILL MOVE ACROSS TUESDAY. MORE OF A ZONAL FLOW
DEVELOPS THEREAFTER.

DIFFERENCES EXIST IN THE AMPLITUDE/STRENGTH OF THE TROUGH ON
TUE/WED...AFFECTING THE TIMING/STRENGTH OF THE RESULTANT FRONTAL
SYSTEM PASSAGE.

SPECIFICALLY...OPER GFS AND ITS ENSEMBLE ARE INDICATING PHASING OF
NORTHERN STREAM ENERGY WITH A SOUTHERN STREAM SHORTWAVE...WITH
ANOTHER COASTAL LOW FOR THE REGION TUE NIGHT/WED. THIS APPEARS TO BE
A LOW PROB SCENARIO...AS THE SHORTWAVE LOOKS TO BE MCS INDUCED...AND
AN INHERENTLY LOW PREDICTABILITY EVENT.

WILL MAINTAIN CONTINUITY WITH MORE PROGRESSIVE FORECAST OF THE
FRONTAL SYSTEM MOVING THROUGH MON NIGHT/TUESDAY. THIS IS IN LINE
WITH ECMWF AND CMC OPER AND ENSEMBLES...WHICH KEEP THIS SOUTHERN
STREAM ENERGY UNPHASED FROM THE NORTHERN STREAM. SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY WOULD BE EXPECTED AHEAD/ALONG THE FRONTAL
SYSTEM MON NIGHT/TUE.

MODELS IN DECENT AGREEMENT WITH DRIER AND SEASONABLE CONDITIONS FOR
THE MIDWEEK PERIOD AS HIGH PRESSURE BUILDS IN.

OVERALL...TEMPERATURES THROUGH THE PERIOD ARE NOT EXPECTED TO
DEVIATE MUCH FROM NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE REMAINS OVER THE TERMINALS THIS AFTERNOON AND TONIGHT.

VFR. WINDS AROUND 10 KT INTO THIS EVENING...MOSTLY SOUTH OF 310
MAGNETIC...BUT COULD OCCASIONALLY BE NORTH OF IT AT KEWR/KLGA UNTIL
AROUND 19Z.

SEA BREEZE EXPECTED AT KJFK/KISP/KBDR/KGON. THERE IS A CHANCE THAT
IT COULD REACH KLGA NEAR 22Z-00Z.

AT JFK...WINDS COULD BE 260-290 UNTIL 19Z. OCCASIONAL GUSTS 17-20KT
POSSIBLE AT JFK THIS AFTN.

FOR SUNDAY...CHC LATE AFTN TSTM.

.OUTLOOK FOR 18Z SUN THROUGH WED...
.SUNDAY AFTERNOON-TUE...SCT SHRA/ISO-SCT TSTM/CHC MVFR. GUSTS AROUND
20 KT SUN AFTN.
.WED-THURS...VFR.

&&

.MARINE...
TRANQUIL CONDS EXPECTED FOR THE WEEKEND AS HIGH PRES BUILDS OVER THE
REGION. WEAK SYSTEM APPROACHES ON SUNDAY...AND CONDS MAY BRIEFLY
BUILD CLOSE TO ADVISORY CONDS ON THE OCEAN WATERS.

MARGINAL SCA SEAS ARE POSSIBLE ON THE OCEAN BY MON OR TUE AS A
PERSISTENT SOUTHERLY FLOW GRADUALLY BUILDS SEAS. THERE IS A LOW
PROBABILITY OF A COASTAL SYSTEM WITH WIDESPREAD SCA CONDS AND HIGH
SEAS TUE NIGHT/WED...WITH MORE LIKELY A RETURN TO SUB SCA CONDS
FOR MIDWEEK AS HIGH PRESSURE BUILDS IN.

&&

.HYDROLOGY...
MAIN STEM RIVERS ARE EXPECTED TO SLOWLY RECEDE TODAY INTO SUNDAY.

THE PROBABILITY FOR SIGNIFICANT WIDESPREAD RAINFALL IS LOW THROUGH
THE MIDDLE OF NEXT WEEK. WITH RECENT HEAVY RAINFALL...ANY ORGANIZED
STRONG CONVECTION SUN THRU TUE WOULD PRESENT A LOCALIZED THREAT FOR
URBAN...POOR DRAINAGE AND SMALL STREAM FLASH FLOODING.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.

&&

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

&&

$$