Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 010534
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
134 AM EDT MON SEP 1 2014

.SYNOPSIS...
A COUPLE OF SURFACE TROUGHS WILL BE IN THE REGION THROUGH MONDAY
EVENING. A WEAK PRESSURE GRADIENT TUESDAY WILL GIVE WAY TO A COLD
FRONT MOVING THROUGH TUESDAY NIGHT WITH HIGH PRESSURE BUILDING IN
FROM THE SOUTH AND WEST MID TO LATE IN THE WEEK. THE HIGH MOVES
OFFSHORE FRIDAY WITH ANOTHER COLD FRONT MOVING IN LATER ON NEXT
SATURDAY AND ACROSS THE AREA NEXT SATURDAY NIGHT WITH HIGH
PRESSURE RETURNING FROM THE WEST THEREAFTER.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WEAK SURFACE TROUGH WILL SLOWLY SINK SE TO THE COAST OVERNIGHT
WHILE WEAKENING. THIS BOUNDARY COULD BECOME SEMI- STATIONARY
ACROSS LI...FAR SE CT...AND POSSIBLY SOUTHERN PORTIONS OF THE NYC
METRO OVERNIGHT BEFORE DISSIPATING LATE. THIS BOUNDARY WILL ACT AS
A FOCUS FOR SCT CONVECTION AS AN ELONGATED SHORTWAVE AXIS
TRAVERSES EASTWARD. ONLY A LOW THREAT OF ANY STRONG STORMS
OVERNIGHT.

MAIN THREAT TONIGHT WITH ANY ADDITIONAL TSTMS WILL BE HEAVY
DOWNPOURS WITH PWATS AROUND 2 INCHES. ADDITIONALLY...THE FLOW
ALOFT WILL BE FAIRLY ALIGNED WITH THE SURFACE TROUGH WHICH WOULD
PROMOTE THE THREAT OF TRAINING SHOWERS AND EMBEDDED TSTMS. WITH
LESSER INTENSITY OF CONVECTION...MAIN THREAT LOOKS TO BE MINOR
URBAN AND POOR DRAINAGE FLOODING.

OVERNIGHT LOWS WILL BE ABOVE NORMAL WITH CLOUD COVER AND A SW
FLOW.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE PATTERN REMAINS SIMILAR AS ANOTHER SURFACE TROUGH SETS UP JUST
TO THE WEST ON MONDAY BEFORE PUSHING THROUGH DURING THE NIGHTTIME.
ANOTHER MID LEVEL SHORTWAVE PASSES THROUGH DURING THE DAY. THIS TIME
AROUND...SOME SYNOPTIC LIFT WILL BE SUPPORTED BY THE RIGHT ENTRANCE
REGION OF AN UPPER JET STREAK PASSING OVER US. SCATTERED SHOWERS AT
LEAST DURING THE DAYTIME...THEN DIMINISHING AND SHIFTING EAST DURING
THE NIGHT AS THE ATMOSPHERE STABILIZES AND MOISTURE CONVERGENCE AND
LIFT MOVE EAST.

SOME THUNDERSTORMS WILL BE AROUND AS WELL AS MLCAPES PROBABLY RISE
INTO THE 1000-1500 J/KG RANGE. THIS TIME HOWEVER THE WINDS ALOFT ARE
NOT QUITE AS FAVORABLE FOR ORGANIZED CONVECTION OR TRAINING OF
CELLS. BUT STRONG THUNDERSTORMS WITH GUSTY WINDS WILL STILL BE
POSSIBLE...AND WITH PWATS AROUND 2 INCHES...LOCALIZED HEAVY RAINFALL
WILL STILL BE A THREAT.

THERE IS A MODERATE RISK OF RIP CURRENTS ON MONDAY...DUE TO
COMBINED 3 TO 5 FT SOUTHERLY WIND WAVES AND A BACKGROUND SE SWELL.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE DOMINANT PATTERN IN THE LONG TERM IS THAT OF RIDGING ON AVERAGE.
ON A LARGE SCALE...RIDGE IS APPARENT ON THE MODEL HEIGHT FIELDS
ALOFT FROM CANADIAN MARITIMES TO THE MID-ATLANTIC TUESDAY. 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. THE LOCAL REGION WILL BE ON THE EDGE OF
THIS TROUGH...WITH MOST FORCING TO THE NORTH OF THE REGION. RIDGING
RESUMES THEREAFTER MID TO LATE WEEK WITH A LARGE RIDGE ACROSS THE
SOUTHERN U.S. PUSHING NORTH. ANOTHER SHORTWAVE WILL APPROACH FROM
THE NORTHWEST FOR NEXT WEEKEND.

A WEAK PRESSURE GRADIENT IS LEFT IN THE REGION BEHIND THE LOW
PRESSURE TROUGH WITHOUT A STRONG PRESENCE OF HIGH PRESSURE TUESDAY.
THE JET PUSHES BACK SOUTH TUESDAY NIGHT INTO EARLY WEDNESDAY...SO
THIS WILL HELP PUSH ANOTHER 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 WITH ANOTHER COLD FRONT APPROACHING SATURDAY AND MOVING
ACROSS SATURDAY NIGHT. THEN HIGH PRESSURE RETURNS...BUILDING IN FROM
THE WEST TO CLOSE OUT NEXT WEEKEND.

OUTSIDE OF WEDNESDAY...A GENERAL SOUTH TO SOUTHWEST FLOW DOMINATES
NEXT WEEK. THE JET STREAM OVERALL KEEPS TO THE NORTH OF THE REGION.
A VERY WARM AND HUMID AIRMASS WILL REMAIN ACROSS THE REGION.
TEMPERATURES REMAIN ABOVE NORMAL THROUGH THE PERIOD...WITH GREATEST
WIDESPREAD POSITIVE TEMPERATURE ANOMALIES TUESDAY THROUGH WEDNESDAY.
MAX TEMPS WILL BE WELL INTO THE 80S AND LOWER 90S IN THE VICINITY OF
NYC AND URBAN NORTHEAST NJ ON TUESDAY...AROUND 10 DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR. LOWS TUESDAY NIGHT AND HIGHS WEDNESDAY
ARE STILL EXPECTED TO BE GENERALLY 5-10 DEGREES ABOVE NORMAL.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL ON AVERAGE
THEREAFTER FOR THE REST OF THE FORECAST PERIOD.

IN TERMS OF WEATHER...A CHANCE OF SHOWERS AND THUNDERSTORMS FROM
NORTHWEST TO SOUTHEAST TUESDAY INTO TUESDAY NIGHT WITH A LITTLE MORE
SHEAR TO WORK...AROUND 25 TO 35 KT 0-6 KM BULK SHEAR...AND
INSTABILITY AS DIAGNOSED BY MUCAPE VALUES RANGING BETWEEN AROUND 500
TO 2000 J/KG. DRY WEATHER RETURNS THEREAFTER WITH THE NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS ON SATURDAY AND SATURDAY NIGHT.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A WEAK SURFACE TROUGH WILL CONTINUE TO SLOWLY SINK SE OF THE NYC
METRO AND DISSIPATE OVERNIGHT. ANOTHER TROUGH APPROACHES LATER
TODAY FROM THE WEST.

MAIN AXIS FOR ADDITIONAL SCATTERED SHOWER AND EMBEDDED TSTM
ACTIVITY IS ALONG THIS WEAKENING TROUGH AXIS. THERE IS A CHANCE
THAT THIS BOUNDARY HANGS UP CLOSE TO KEWR/KJFK AND PARTICULARLY
KISP BEFORE DISSIPATING...WHICH WOULD PROLONG THE THREAT OF SHRA
INTO LATE TONIGHT.

OTHERWISE...WITH LIGHT WINDS AND MOIST AIRMASS MVFR/IFR CEILINGS
AND VSBYS ARE POSSIBLE. ANY STRATUS AND FOG WILL SLOWLY BURN OFF
THIS MORNING...WITH GENERALLY VFR CONDITIONS AT NYC/NJ TERMINALS
BY 16Z MON. STRATUS COULD HOLD ON ACROSS EASTERN TERMINALS INTO
EARLY AFTERNOON.

SCT SHRA/TSRA DEVELOPMENT EXPECTED ONCE AGAIN MON
AFT/EVE...PARTICULARLY NYC METRO AND INTERIOR TERMINALS.

WINDS REMAIN LIGHT S/SW THROUGH THE OVERNIGHT AND EARLY MORNING
HOURS...INCREASING TO 8 TO 12 KT DURING THE DAY.

.OUTLOOK FOR 06Z TUE THROUGH FRI...
.MON NIGHT...MVFR STRATUS/FOG POSSIBLE LATE MON NIGHT.
.TUE...MAINLY VFR EXCEPT FOR SCT AFT/EVE SHRA/TSRA.
.WED-FRI...VFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
SW FLOW OF AROUND 15KT ON THE OCEAN WATERS TONIGHT IS EXPECTED TO
BUILD SEAS ON THE OCEAN TO 5FT. THERE IS A CHANCE THAT SEAS FALL
JUST SHORT OF 5FT...HOWEVER THERE IS NOT ENOUGH CONFIDENCE THAT SEAS
DON`T TOUCH 5FT TO REMOVE THE CURRENT SCA WHICH IS POSTED FOR
TONIGHT. FOR THE OTHER WATERS...WINDS ARE EXPECTED TO REMAIN BELOW
SCA LEVELS. LOCALLY STRONG GUSTS WOULD HOWEVER BE POSSIBLE IN ANY
THUNDERSTORMS THAT HOLD TOGETHER THIS EVENING.

THE PRESSURE GRADIENT REMAINS WEAK MONDAY THROUGH FRIDAY
WITH RIDGING THE MORE DOMINANT PATTERN. CONDITIONS ARE EXPECTED TO
REMAIN BELOW SCA ON THE WATERS THROUGH THIS TIME PERIOD.

&&

.HYDROLOGY...
ON AVERAGE...ABOUT AN INCH TO AN INCH AND A HALF OF RAINFALL IS
EXPECTED THROUGH MONDAY ACROSS THE BASINS. DUE TO THE CONVECTIVE
NATURE OF THE RAINFALL DISTRIBUTION...THERE WILL BE AREAS THAT
RECEIVE MUCH LESS...AND SOME AREAS THAT COULD SEE OVER 2 INCHES
OF RAINFALL DURING THIS PERIOD. THAT HAS ALREADY OCCURRED.

MAINLY A MINOR URBAN AND POOR DRAINAGE FLOOD THREAT OVERNIGHT INTO
MON MORNING. LOCALIZED HEAVY RAINFALL AND FLASH FLOODING POSSIBLE
ONCE AGAIN MON AFT/EVE.

NO SIGNIFICANT WIDESPREAD RAINFALL EXPECTED TUESDAY THROUGH THE REST
OF THE WORK WEEK.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
     ANZ355.
     SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350-
     353.

&&

$$
SYNOPSIS...JC/JM
NEAR TERM...JC/NV
SHORT TERM...JC
LONG TERM...JM
AVIATION...BC/NV
MARINE...JC/JM/PW
HYDROLOGY...JC/JM/NV





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