Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 311735
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
135 PM EDT THU JUL 31 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFF THE NORTHEAST COAST THROUGH FRIDAY
WHILE WEAK DISTURBANCE MOVES THROUGH THE REGION. A FRONTAL
BOUNDARY WILL BACK IN FROM THE OCEAN THIS WEEKEND AND IMPACT THE
AREA THROUGH THE BEGINNING OF THE WEEK. HIGH PRESSURE THEN BUILDS
INTO THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRES REMAINS OVER THE MID-ATLANTIC...AND WEAK SHORTWAVE
IN THE MIDDLE LEVELS OF THE ATMOSPHERE CONTINUES TO WORK ITS WAY
NORTH OF THE REGION. ML MUCAPE VALUES ARE AVERAGING 500-750 J/KG
ACROSS MOST OF THE REGION...AND ARE TOPPING 1000 J/KG ACROSS
NORTHERN PORTIONS OF THE LOWER HUDSON VALLEY. THERE IS ALSO 30-40
KT OF 0-6 KM BULK SHEAR ACROSS THE REGION. HOWEVER...THERE IS
LITTLE LIFT IN THE ATMOSPHERE AS MOST OF THE ENERGY REMAINS NORTH
OF THE REGION.

WILL GO AHEAD AND DROP BACK POPS BY ABOUT 10-15 PERCENT...DROPPING
POPS FROM CHANCE TO SLIGHT CHANCE FOR MOST OF THE WESTERN HALF OF
THE CWA AND WILL DROP POPS FOR FAR SE CT AND EASTERN SUFFOLK
COUNTY.

MAX TEMPS TODAY TOPPING OFF IN THE UPPER 70S TO LOW 80S WITH THE
WARMEST TEMPS ACROSS NYC AND NE NJ.

THERE REMAINS A MODERATE RISK FOR RIP CURRENTS THIS AFTERNOON WITH
AFTERNOON SEABREEZE DEVELOPMENT AND 3 FT S/SE SWELLS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
ANY SHOWER ACTIVITY WILL TAPER OFF IN THE EVENING. TEMPS NEAR
SEASONABLE AS MOISTURE LEVELS GRADUALLY INCREASE WITH LIGHT
ONSHORE FLOW...GENERALLY IN THE 60S. PATCHY FOG POSSIBLE ACROSS
OUTLYING AREAS AS A RESULT.

DEEP TROUGHING ACROSS EASTERN 1/2 OF THE US...DEEPENS SOUTHERLY FLOW
UP THE EAST COAST. INCREASING MOISTURE/INSTABILITY ALONG WITH
SOUTHERN STREAM SHORTWAVE ENERGY RIDING UP THE COAST AND WEAK RIGHT
REAR JET LIFT WILL PRESENT A BETTER CHANCE FOR DIURNAL SHRA/TSRA
ACTIVITY FOR NYC METRO AND PARTICULARLY POINTS N&W FRI AFT/EVE.

OVERALL SHEAR LOOKS WEAK...SO WOULD EXPECT CONVECTION TO BE MORE
PULSE IN NATURE...BUT CANT RULE OUT A FEW STRONG STORMS. 15 KT SSE
STEERING FLOW WILL LEND TO AN URBAN/POOR DRAINAGE FLOOD POTENTIAL.

TEMPS NEAR SEASONABLE IN MODERATING AIRMASS...LOWER 80S TO 85.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROUGH REMAINS TO THE EAST OF THE AREA FRIDAY NIGHT ALONG
WITH A STRONG WESTERN ATLANTIC HIGH PRESSURE AREA. AS THE HIGH
RETROGRADES WEST...IT WILL PUSH A FRONT TO THE WEST WITH IT. WITH
THE BLOCKING PATTERN IN PLACE DUE TO THE UPPER LOW TO THE WEST...THE
FRONT WILL SIT NEAR AND/OR OVER THE AREA THROUGH THE WEEKEND.

A CONTINUOUS SOUTH-SOUTHWEST FLOW WILL ALSO HELP BRING SUFFICIENT
MOISTURE INTO THE AREA. THE RIGHT ENTRANCE REGION OF AN UPPER JET
ALSO SITS OVER THE REGION THROUGH THE WEEKEND. A COMBINATION OF
THESE WILL KEEP UNSETTLED AND SHOWERY CONDITIONS OVER THE AREA. SOME
OF THE SHOWERS/THUNDERSTORMS COULD PRODUCE MODERATE TO HEAVY
RAINFALL.

12Z ECMWF IS A WETTER SOLUTION WITH THE FRONT SETTING UP ACROSS THE
AREA WHILE THE GFS/NAM KEEPS IT TO THE SOUTH WHICH KEEPS THE AREA
DRY THROUGH SUNDAY MORNING. WITH SO MUCH UNCERTAINTY REMAINING...DID
NOT MAKE ANY MAJOR CHANGES TO THE POP GRIDS AND LEFT CHANCE FOR MUCH
OF THE AREA SATURDAY AND SUNDAY.

TEMPERATURES THROUGH THE WEEKEND WILL BE NEAR NORMAL...MAYBE
SLIGHTLY BELOW NORMAL FOR HIGHS. WITH INCREASING DEW POINTS DUE TO
THE MULTIPLE NIGHTS OF SOUTHERLY WIND...HAVE ADDED PATCHY FOG FOR
SUNDAY AND MONDAY NIGHTS.

A SURFACE LOW THEN DEVELOPS OVER THE SE IN RESPONSE TO THE DEEP
UPPER TROUGH. THIS QUICKLY TRACKS NE OVER THE LOCAL AREA ON MONDAY.
ECMWF FLATTENS THE UPPER LEVELS QUICKER ON MONDAY WHILE THE GFS
LEAVES THE SURFACE LOW LINGERING ACROSS THE NORTHEAST WITH A WET
SUNDAY AND MONDAY. AGAIN...WILL MAKE NO MAJOR CHANGES TO THE POP
FORECAST.

DRY WEATHER THEN EXPECTED TUES AND WED. TEMPS WILL BEGIN TO WARM
MON-WED AS HEIGHTS RISE A FEW DEGREES WITH MORE BREAKS IN THE SUN
THAN THE WEEKEND. LOWS WILL REMAIN NEAR NORMAL.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL REMAIN OFFSHORE INTO FRIDAY AFTERNOON.

VFR THROUGH THE TAF PERIOD. CONVECTIVE POTENTIAL HAS APPEARED TO
DECREASE ACROSS THE REGION THIS AFTERNOON...SO HAVE REMOVED TEMPO
GROUP FOR SHRA AT KSWF. WHILE CANNOT COMPLETELY RULE OUT A
SHRA/TSTM AT CITY AND WESTERN TERMINALS...THE PROBABILITY OF
OCCURRENCE AT ANY GIVEN TERMINAL IS 10 PERCENT OR LESS.

SW WINDS VEER TO THE S AND INCREASE INTO THE AFTERNOON...AND WILL
BE GUSTY AT CITY TERMINALS...WITH A SEABREEZE COMPONENT. WINDS
BECOME LIGHT AND VARIABLE THIS EVENING...THEN INCREASE OUT OF THE
S-SE MID-LATE FRIDAY MORNING.

     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: TIMING OF START/END OF GUSTY WINDS THIS
AFTERNOON AND LIGHT AND VARIABLE WINDS THIS EVENING COULD BE OFF
+/- 1-2 HOURS.

KLGA FCSTER COMMENTS: TIMING OF THE END OF GUSTY WINDS THIS
AFTERNOON AND START/END OF LIGHT AND VARIABLE WINDS THIS EVENING
COULD BE OFF +/- 1-2 HOURS.

KEWR FCSTER COMMENTS: TIMING OF THE END OF GUSTY WINDS THIS
AFTERNOON AND START/END OF LIGHT AND VARIABLE WINDS THIS EVENING
COULD BE OFF +/- 1-2 HOURS.

KTEB FCSTER COMMENTS: TIMING OF THE END OF GUSTY WINDS THIS
AFTERNOON AND START/END OF LIGHT AND VARIABLE WINDS THIS EVENING
COULD BE OFF +/- 1-2 HOURS.

KHPN FCSTER COMMENTS: TIMING IN CHANGES IN WIND DIRECTION/SPEED
COULD BE OFF +/- 1-2 HOURS.

KISP FCSTER COMMENTS: TIMING IN CHANGES IN WIND DIRECTION/SPEED
COULD BE OFF +/- 1-2 HOURS.

.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
.FRIDAY-FRIDAY NIGHT...MAINLY VFR. ISOLD SHRA/TSTMS POSSIBLE IN
THE AFTERNOON/EVENING.
.SATURDAY-SUNDAY NIGHT...AREAS OF MVFR OR LOWER POSSIBLE.
.MONDAY-TUESDAY...MAINLY VFR. ISOLD SHRA/TSTMS POSSIBLE IN
THE AFTERNOON/EVENING.

&&

.MARINE...
WITH HIGH PRES OVER THE WATERS...CAN EXPECT SUB-SMALL CRAFT
ADVISORY CONDITIONS THROUGH FRIDAY. WINDS AND SEAS WILL CONTINUE
TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS FRIDAY NIGHT-MONDAY.

&&

.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH TONIGHT.

LOCALLY HEAVY DOWNPOURS IN SCATTERED TSTMS ON FRIDAY WILL PRESENT
MAINLY A URBAN/POOR DRAINAGE FLOOD THREAT DUE TO AROUND 15 KT
MOVEMENT...WITH A LOW AND LOCALIZED FLASH FLOOD THREAT WITH ANY
TRAINING OF CELLS.

AN INCREASINGLY MOIST AIR MASS WILL BE CONDUCIVE TO THE DEVELOPMENT
OF HEAVY SHOWERS THIS WEEKEND.

&&

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

&&

$$

SYNOPSIS...NV
NEAR TERM...MPS/NV
SHORT TERM...NV
LONG TERM...LN
AVIATION...MALOIT
MARINE...NV/LN
HYDROLOGY...NV/LN





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