Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Upton, NY banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4]



000
FXUS61 KOKX 312359
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
759 PM EDT SUN AUG 31 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 MONDAY MORNING/...
STRONGEST CONVECTION WILL PUSHING OFF EASTERN LI/SE CT SHORTLY.
WEAK SURFACE TROUGH WILL GRADUALLY SINK SE FROM THE LOWER HUDSON
VALLEY/SW CT/NE NJ THROUGH THE EVENING AND THIS BOUNDARY COULD
BECOME SEMI- STATIONARY ACROSS LI AND POSSIBLY SOUTHERN PORTIONS OF
THE NYC METRO OVERNIGHT BEFORE DISSIPATING LATE. THIS BOUNDARY
WILL ACT AS A FOCUS FOR ADDITIONAL ISOLATED-SCT CONVECTION AS A
SHORTWAVE AXIS TRAVERSES EASTWARD.

THREAT FOR SEVERE WEATHER HAS COME TO AND END WITH EARLIER
CONVECTION AND NIGHTFALL STABILIZING ENVIRONMENT. 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
INTENSITY OF CONVECTION LESSENING...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 MONDAY MORNING THROUGH MONDAY NIGHT/...
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.

&&

.LONG TERM /TUESDAY 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 /00Z MONDAY THROUGH FRIDAY/...
A WEAK SURFACE TROUGH...JUST NW OF NYC AS OF 00Z...WILL CONTINUE
TO SLOWLY SINK SE AND THEN DISSIPATE OVERNIGHT. ANOTHER TROUGH
APPROACHES MONDAY FROM THE WEST.

MAIN AXIS FOR ADDITIONAL SCT SHOWER AND ISOLATED TSTM ACTIVITY
WILL BE ALONG THE APPROACHING TROUGH AXIS...WHICH SHOULD PASS SE
OF NYC TERMINALS BY AROUND 04-06Z. 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 MORNING STRATUS AND FOG WILL SLOWLY
BURN OFF MONDAY MORNING...WITH GENERALLY VFR CONDS 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 MONDAY MORNING
HOURS...INCREASING TO 8 TO 12 KT DURING THE DAY. 

.OUTLOOK FOR 00Z 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 MONDAY FOR ANZ350-353-355.

&&

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






National Weather Service
Disclaimer Privacy Policy