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 011507
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1107 AM EDT MON SEP 1 2014

.SYNOPSIS...
A SURFACE TROUGH OVER THE AREA THIS AFTERNOON DISSIPATES AS IT
SHIFTS EAST 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/...
MINOR CHANGES MADE WITH THIS UPDATE. REDUCED THE AMOUNT OF CLOUD
COVER FOR THE DURATION OF THE MORNING...BUT THE EXPECTATION IS
THAT CUMULUS STARTS TO FILL BACK IN LATE THIS MORNING ALONG THE
SEA BREEZE BOUNDARIES OF CT AND LI...AS WELL AS ALONG A TROUGH
SITUATED JUST WEST OF THE CITY. A SHORTWAVE APPROACHING FROM SOUTH
CENTRAL PA WILL PROVIDE SOME LIFT FOR AT LEAST THE SOUTHERN ZONES
THIS AFTN. MEANWHILE...WE DESTABILIZE WITH DAYTIME HEATING AND
HIGH DEWPOINTS. MODERATE CAPE 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.

RAISED HIGH TEMPS A COUPLE OF DEGREES FOR THE CITY AND SOME SPOTS
NORTH AND WEST AS THERE HAS BEEN MORE SUNSHINE THAN PREVIOUSLY
FORECAST. LOOKS LIKE WIDESPREAD HEAT INDICES FALL JUST SHORT OF 95
IN THE CITY THIS AFTN. THIS WILL NEED TO BE TAKEN INTO
CONSIDERATION FOR A POTENTIAL ADVISORY. THE UNCERTAINTY OF CLOUD
COVER THIS AFTN AND CONSEQUENTIAL HIGH TEMPS...PLUS MARGINAL
CRITERIA INDICES FOR TOMORROW COMPLICATE THE FORECAST.

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 /15Z MONDAY THROUGH FRIDAY/...
A WEAK SURFACE TROUGH WILL REMAIN OVER THE REGION TODAY. 

ANY COASTAL STRATUS WILL GIVE WAY TO GENERALLY VFR CONDITIONS.

WITH HEATING...EXPECT AFTERNOON BROKEN CU TO DEVELOP.
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT IS EXPECTED ONCE
AGAIN THIS AFTERNOON AND EVENING...PARTICULARLY THE NYC METRO AND
INTERIOR TERMINALS. AGAIN THOUGH...TOO SCATTERED TO INCLUDE IN
FORECASTS AS LOCATION IS HARD TO PINPOINT.

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: SEA BREEZE EXPECTED...WITH TIMING OFF BY AN
HOUR OR TWO. AMENDMENT FOR A POP UP THUNDERSTORM IS POSSIBLE.

KLGA FCSTER COMMENTS: SEA BREEZE EXPECTED...WITH TIMING OFF BY AN
HOUR OR TWO. AMENDMENT FOR A POP UP THUNDERSTORM IS POSSIBLE.

KEWR FCSTER COMMENTS: MAINLY SW WIND EXPECTED...ALTHOUGH THERE IS
SOME CONCERN FOR A SE SEA BREEZE TO IMPACT THE TERMINALS AFTER
18Z. AMENDMENT FOR A POP UP THUNDERSTORM IS POSSIBLE.

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

KTEB FCSTER COMMENTS: AMENDMENT FOR A POP UP THUNDERSTORM IS POSSIBLE.

KHPN FCSTER COMMENTS: SEA BREEZE EXPECTED...WITH TIMING OFF BY AN
HOUR OR TWO. AMENDMENT FOR A POP UP THUNDERSTORM IS POSSIBLE.

KISP FCSTER COMMENTS: STRATUS AND IFR CIGS SHOULD IMPROVE TO VFR
BEFORE 18Z.

.OUTLOOK FOR 12Z TUE THROUGH FRI...
.TUE...MAINLY VFR EXCEPT FOR SCT AFT/EVE SHRA/TSRA. 
.WED-FRI...VFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
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...NONE.

&&

$$






National Weather Service
Disclaimer Privacy Policy