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Area Forecast Discussion
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000
FXUS61 KOKX 010821
AFDOKX

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

.SYNOPSIS...
AS ONE SURFACE TROUGH DEPARTS THIS MORNING...ANOTHER WILL DEVELOP
WEST OF NEW YORK CITY THIS AFTERNOON AND REMAIN JUST WEST OF THE
AREA THROUGH TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON
TUESDAY AND MOVES THROUGH TUESDAY NIGHT...WITH HIGH PRESSURE 
BUILDING IN FOR THE LATTER HALF OF THE WEEK. ANOTHER COLD FRONT WILL 
IMPACT THE REGION THIS WEEKEND. 

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE A FEW SHOWERS POPPING UP OVER LONG ISLAND AND NYC...CONVECTIVE
ACTIVITY HAS REMAINED SOUTH OF LONG ISLAND OVERNIGHT. THE LAST OF
IT WILL PUSH E OF THE COASTAL WATERS SHORTLY AFTER SUNRISE. A VERY
HUMID AIRMASS WILL REMAIN IN PLACE AND IT WON'T TAKE MUCH TO
TRIGGER AN ISOLD SHOWER...SO EVEN THOUGH THERE WILL BE A BREAK IN
WIDESPREAD SHRA/TSTMS THIS MORNING...HAVE KEPT SCHC POPS (LOW CHC
ON LI) IN THE FORECAST WITH A FEW WEAK PIECES OF ENERGY PASSING
THROUGH ALOFT.

MOSTLY CLOUDY CONDS WILL LIKELY PREVAIL...ALTHOUGH ANTICIPATED BREAKS
OF SUN THIS AFTERNOON WILL ALLOW TEMPS TO INTO THE 80S WITH H85
TEMPS AROUND 17C. THE PARTIAL SUNSHINE WILL ALSO ALLOW THE
ATMOSPHERE TO DESTABILIZE AS A MID LEVEL SHORTWAVE APPROACHES.
MARGINALLY MODERATE CAPE FORECAST IN A LOW SHEAR ENVIRONMENT
SHOULD RESULT IN SCT PULSE STORMS THIS AFTN. COULD BE A FEW
STRONGER STORMS...ALTHOUGH DUE TO THE WEAK SHEAR NOT EXPECTING
SEVERE. MORE IMPORTANTLY...PWATS WILL REMAIN AROUND 2 INCHES AND
STORMS WILL BE MOVING SLOWER THAN YESTERDAY SO AN ISOLD FLASH
FLOOD THREAT REMAINS...MAINLY IN URBANIZED AREAS. NOT WIDESPREAD
ENOUGH FOR A WATCH HOWEVER. 

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

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SHRA/TSTMS DIMINISH AND SHIFT EWD DURING THE EVENING AS THE
ATMOSPHERE STABILIZES AND MOISTURE CONVERGENCE AND LIFT MOVE EAST.

THE HEAT AND HUMIDITY WILL CONTINUE THROUGH TUE WITH H85 TEMPS
REMAINING AROUND 17-18C AND MIXING TO THIS HEIGHT. CLOUD COVER
WILL INCREASE DURING THE AFTN AS A COLD FRONT APPROACHES FROM THE
W...BUT WE SHOULD STILL MAX OUT IN THE UPPER 80S TO LOWER 90S
ACROSS A GOOD PORTION OF THE FORECAST AREA.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
PCPN CHANCES DISSIPATE QUICKLY TUESDAY NIGHT AS AN UPPER LEVEL 
TROUGH SWINGS THROUGH THE NORTHEAST...WHILE THE SURFACE LOW LIFTS 
NORTH...DRAGGING ITS ASSOCIATED COLD FRONT THROUGH. GENERAL 
AGREEMENT BETWEEN THE 00Z MODEL SOLUTIONS WITH THE FRONT MOVING 
THROUGH BETWEEN 00-06Z. ALOFT...THE BETTER FORCING WITH THE 
SHORTWAVE LOOKS TO REMAIN WELL NORTH OF THE REGION...WITH ONLY A 
WEAK SHORTWAVE PASSING THROUGH DURING THE 00-06Z TIMEFRAME. AS 
SUCH...WILL CAP POPS AT HIGHER END CHC THROUGH 03Z OVER AREAS 
NORTH/WEST NYC METRO...THEN TAPER OFF WITH ALL AREAS BCMG DRY BY 
06Z. LINGERING INSTABILITY UP TO 1000 J/KG COULD SEE AN ISO TSTM 
STILL PSBL TUES EVENING RIGHT AHEAD OF THE FRONT. HIGH PRESSURE 
QUICKLY BUILDS IN AT THE SURFACE WHILE A SEMI-ZONAL FLOW TAKES HOLD 
BRIEFLY ALOFT. 

BY WEDNESDAY SEEING DRYING CONDITIONS AS THE HIGH DEEPENS AND RIDGING BUILDS 
ACROSS THE EASTERN HALF OF THE US. NO PCPN EXPECTED WED-FRI UNDER 
SUCH A PATTERN. A QUICK SHOT OF COOLER AIR WED IN THE WAKE OF THE 
FRONT WITH THE NORTHERLY FLOW WILL PUSH TEMPS BACK A FEW 
DEGREES...THOUGH STILL REMAINING WELL ABOVE NORMAL. RISING HEIGHTS 
WITH THE BUILDING RIDGE WILL INCREASE TEMPS ONCE AGAIN BY WEEKS 
END...ESP WITH A STRONGER SURGE OF WARMER AIR WITH THE SOUTHERLY 
FLOW SETTING UP AHEAD OF THE NEXT APPROACHING COLD FRONT. 

00Z GFS/CMC BEGIN APPROACHING THE COLD FRONT LATE FRIDAY...BRINGING 
IT THROUGH BY SAT MORNING WHILE THE ECMWF REMAINS THE SLOWER 
SOLUTION...MOVING THE FRONT THROUGH LATE SAT. QUESTION REMAINS TO 
WHAT EXTENT THE RIDGE BUILDS...WITH THE GFS/CMC ACTUALLY SIDING 
CLOSER TO MORE ZONAL FLOW WHILE THE ECMWF HAS A MORE PRONOUNCED 
RIDGE WHICH IN TURN TAKE LONGER TO WEAKEN. FOR NOW...SIDED MORE 
WITH THE ECMWF SOLUTION FOR TIMING...THOUGH EVEN THAT COULD BE A BIT 
SLOW AND RIDGING OVERDONE...WITH A GOOD COMPROMISE BEING SWINGING 
THE FRONT THROUGH SOMETIME SATURDAY. WITH THE UNCERTAINTY TOPPED 
POPS AT CHC DURING THE DAY SAT...AND INTO THE FIRST HALF OF SUNDAY 
NIGHT. BOTH THE GFS AND ECMWF HINT AT THE FRONT LINGERING JUST 
OFFSHORE DURING THE DAY SUNDAY...AND THE ECMWF EVEN ON INTO MONDAY. 
WILL MAINTAIN SLIGHT CHC POPS FOR SUNDAY MORNING TO ACCOUNT FOR THE 
FRONTAL PLACEMENT. TEMPS QUICKLY REBOUND TO NEAR NORMAL TO SLIGHTLY 
BELOW BY SUNDAY AS WELL WITH THE TROUGH USHERING IN MUCH COOLER 
TEMPS ALOFT. 

&&

.AVIATION /08Z 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 RAIN AND EMBEDDED THUNDER WILL REMAIN SOUTH OF LONG 
ISLAND...KEEPING THE TERMINALS MOSTLY DRY THIS MORNING. THERE MAY 
HOWEVER BE A FEW STRAY ISOLATED SHOWERS THAT POP UP. 

WITH LIGHT WINDS AND A 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. 
STRATUS COULD HOLD ON ACROSS EASTERN TERMINALS INTO EARLY AFTERNOON.

SCATTERED SHOWERS AND THUNDERSTORM DEVELOPMENT IS EXPECTED ONCE 
AGAIN THIS AFTERNOON AND EVENING...PARTICULARLY THE NYC METRO AND 
INTERIOR TERMINALS.

THE LIGHT SOUTH/SOUTHWEST WINDS WILL...INCREASING TO 8 TO 12 KT 
DURING THE DAY.

...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: AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON.

KLGA FCSTER COMMENTS:  AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON.

KEWR FCSTER COMMENTS:  AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES 
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS:  AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON.

KHPN FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON. 

KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT 
CATEGORIES AND TIMING OF PRECIPITATION LATE THIS MORNING AND 
AFTERNOON.

.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...
SEAS WEST OF FIRE ISLAND INLET HAVE LIKELY DROPPED BELOW SCA
LEVELS...THEREFORE HAVE CANCELLED THE ADVSY THERE. EAST OF HERE
SEAS BETWEEN 4 AND 6 FT WILL CONTINUE THROUGH MID MORNING. NO
CHANGES TO TIMING OF HEADLINES...ALTHOUGH HAVE CONVERTED THE
GENERIC SCA TO AN SCAHZ SINCE GUSTS ARE NO LONGER EXPECTED TO
REACH 25 KT.

GENERALLY SUB-SCA CONDITIONS THEN EXPECTED ON THE WATERS THROUGH
FRIDAY UNDER THE HIGH PRESSURE. AN OCCASIONAL GUST TO 25 KTS MIGHT
BE POSSIBLE ON THE OCEAN WATERS TUES EVENING RIGHT AHEAD OF THE
COLD FRONTAL PASSAGE.

WINDS INCREASE AHEAD OF THE NEXT FRONT LATE FRIDAY INTO 
SATURDAY...WITH POSSIBLE GUSTS REACHING 25 KTS DURING THIS TIME. 
WAVES/SEAS WILL BUILD IN RESPONSE TO INCREASING WINDS...THOUGH AT 
THE MOMENT EXPECTING SEA CONDITIONS TO REMAIN SUB-SCA. WAVEWATCH WAS 
QUICK TO BUILD THE SEAS...SIDING WITH THE QUICKER GFS SOLUTION...SO 
DROPPED GUIDANCE AROUND 1 FT FOR FRI NIGHT/SAT TO REFLECT A SLOWER 
SOLUTION. 

&&

.HYDROLOGY...
BASIN AVERAGE RAINFALL IS EXPECTED TO BE AROUND 1/4 INCH TODAY.
DUE TO THE CONVECTIVE NATURE OF THE RAINFALL DISTRIBUTION...THERE
WILL BE AREAS THAT RECEIVE LITTLE TO NO RAINFALL...AND SOME AREAS
THAT COULD SEE OVER AN INCH.

MAINLY A MINOR URBAN AND POOR DRAINAGE FLOOD THREAT
TODAY...ALTHOUGH ISOLD FLASH FLOODING IS POSSIBLE WITH A WATER
LOADED ATMOSPHERE.

NO SIGNIFICANT PRECIPITATION RESULTING IN HYDROLOGIC ISSUES IS 
CURRENTLY FORECASTED WED THROUGH THIS WEEKEND. 

&&

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

&&

$$




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