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Area Forecast Discussion
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000
FXUS61 KOKX 212354
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
754 PM EDT MON JUL 21 2014

.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE AREA THROUGH TONIGHT...THEN SLIDES 
OFFSHORE ON TUESDAY. A COLD FRONT WILL MOVE INTO THE NORTHEAST 
WEDNESDAY...THEN SLOWLY MOVE ACROSS THE AREA THROUGH THURSDAY. HIGH 
PRESSURE WILL FOLLOW FROM THURSDAY NIGHT INTO THE WEEKEND. ANOTHER 
LOW PRESSURE SYSTEM WILL APPROACH FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ISOLATED SHRA ACTIVITY DEVELOPING OFF THE CATSKILLS IN RESPONSE
TO PASSING SHORTWAVE AND MARGINAL INSTABILITY...SHOULD DISSIPATE
AS IT SINKS SE...BUT WILL BRING A BRIEF SHOWER THREAT INTO NORTHERN
ORANGE/PUTNAM THROUGH 9 PM OR SO.

OVERNIGHT...THE UPPER TROUGH IS EXITING THE COAST WITH RIDGING
BUILDING IN ITS WAKE. SUBSIDENCE WILL GENERALLY HINDER ANY SHOWER
DEVELOPMENT...MAINTAINING DRY CONDITIONS ACROSS THE AREA.

PATCHY FOG POSSIBLE ACROSS FAR OUTLYING AREAS...WITH SOME
MODERATION IN DEWPOINTS THIS EVENING AND RADIATIONAL COOLING.

LOW TEMPERATURES IN THE 60S /CLOSE TO CLIMATOLOGICAL NORMAL/ CAN BE 
EXPECTED.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
SUBSIDENCE OWING TO A BUILDING RIDGE WILL MAINTAIN DRY CONDITIONS 
THROUGH TUESDAY MORNING. BY AFTERNOON...UPPER LEVEL HEIGHT FALLS AND 
CONVERGENCE ALONG A SUBTLE SURFACE TROUGH WILL LEAD TO A SLIGHT 
CHANCE OF THUNDERSTORMS ACROSS NORTHERN NJ...SOUTHEAST NY AND 
WESTERN CT. ALTHOUGH SURFACE-BASED CAPE VALUES ARE FORECAST AROUND 
500-1000 J/KG...DEEP LAYER FLOW AVERAGING LESS THAN 15KT WILL KEEP 
STORMS SUB-SEVERE. HOWEVER...BRIEF GUSTY WINDS NEAR THUNDERSTORMS 
ARE POSSIBLE GIVEN DRIER AIR/SUPER ADIABATIC LAPSE RATES BENEATH 5000 
FT. 

RIDGING ALOFT AND SOUTHWEST FLOW WILL LEAD TO HIGH TEMPERATURES NEAR 
OR A FEW DEGREES ABOVE CLIMATOLOGICAL NORMALS FOR TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ATTENTION MID WEEK WILL BE FOCUSED ON THE PROGRESSION OF A SLOW 
MOVING COLD FRONT ACROSS THE NORTHEAST. GENERALLY DECENT MODEL 
AGREEMENT BETWEEN THE 12Z MODEL SUITE...MINUS THE ECMWF...ON THE 
TIMING OF THE FRONT REACHING THE AREA OVERNIGHT WED. THE FRONT THEN 
LOOKS TO STALL JUST OFFSHORE...WITH A SFC LOW THEN FORMING AND 
RIDING THE FRONT THURS...BRINGING ANOTHER CHC OF PCPN DURING THE DAY 
THURS...EVENTUALLY TAPERING OFF THURS NIGHT AS HIGH PRESSURE BUILDS 
IN BEHIND THE FRONT. 

BEGINNING WED DURING THE DAY...SFC LOW TREKKING THROUGH SOUTHERN 
CANADA WILL DRAG THE ASSOCIATED COLD FRONT THROUGH THE GREAT 
LAKES...EVENTUALLY HAVING THE FRONT NEAR SOUTHERN NEW ENGLAND BY 00Z 
THURS. STRONG WAA OUT AHEAD OF THE FRONT WILL LOOK TO INJECT IN A 
VERY WARM...MOIST ATMO. MULTIPLE WEAK VORT MAXES WILL MOVE THROUGH 
THE NORTHEAST THROUGHOUT THE DAY OUT AHEAD OF THE MAIN UPPER LVL 
TROUGH...WHICH COMBINING WITH DECENT INSTABILITY AND MARGINAL SHEAR 
COULD PRODUCE AN ISO TSTM OVER AREAS WELL NORTH AND WEST OF NYC 
METRO. WHILE THE SVR THREAT LOOKS TO REMAIN NORTH OF THE 
AREA...CANNOT RULE OUT A STRONGER STORM OVER LOWER HUDSON AND 
INTERIOR SW CT AREAS. THE MAIN PCPN EVENT FOR THE AREA WILL THEN BE 
AS THE COLD FRONT SWINGS THROUGH WED NIGHT. EXPECTING THE THREAT FOR 
THUNDER TO DIMINISH OVERNIGHT WITH LOSS OF INSTABILITY/HEATING...SO 
THINKING THE THREAT WILL TURN MORE TO HEAVY RAIN AND POTENTIAL FOR 
FLOODING WITH PWATS HITTING AROUND 2 INCHES. POSSIBLE BREAK IN THE 
PCPN EARLY THURS...THEN ANOTHER ROUND DURING THE DAY AS THE 
AFOREMENTIONED SFC LOW FORMS ALONG THE FRONT AND PUSHES TO THE 
NORTHEAST AND EAST. MINIMAL INSTABILITY THURS WILL KEEP A LOWER CHC 
THREAT FOR TSTMS...MAINLY OVER LI AND TO THE SOUTH. WILL MAINTAIN 
CHC POPS FOR NOW WITH UNCERTAINTY ON THE EXACT TIMING OF THE PCPN. 

PCPN TAPERS OFF THURS NIGHT AS FRONT EXITS THE REGION AND SFC HIGH 
BUILDS IN FROM THE WEST. MUCH COOLER AND DRIER AIRMASS MOVES IN BEHIND 
THE FRONT FOR FRI AS THE REGION SITS BETWEEN THE DEPARTING UPPER LVL 
TROUGH AND RIDGING OVER THE CENTRAL US...RESULTING IN DRY AND MOSTLY 
SUNNY SKIES. EXPECT THE DRY WX TO CONTINUE THROUGH SAT. 

SOME MODEL DISCREPANCY THEN SUNDAY INTO THE BEGINNING OF NEXT WEEK 
WITH THE HANDLING OF THE NEXT LOW PRESSURE SYSTEM. 00Z ECMWF WAS THE 
MORE PROGRESSIVE OF THE SOLUTIONS PUSHING THE LOW THROUGH SUN NIGHT 
INTO MON. HOWEVER... THE 12Z MODEL SUITES A BIT SLOWER IN HOLDING 
THE LOW BACK OVER THE GREAT LAKES. WITH THE UNCERTAINTY...MAINTAINED 
THE PREVIOUS THINKING OF CHC POPS FOR THE PERIOD FOR NOW UNTIL THE 
MODELS COME INTO BETTER AGREEMENT. 

AS MENTIONED...STRONG SURGE OF WARM AIR WED WILL PUSH TEMPS WELL 
ABOVE NORMAL...WITH SOME SPOTS OF NYC METRO POTENTIALLY EVEN HITTING 
90. THE ONSHORE FLOW WILL ALLOW FOR IMMEDIATE COASTAL AREAS TO
HOVER IN LOWER-MID 80S. TEMPS WILL THEN DROP THURS AND FRI TO A
FEW DEGREES BELOW NORMAL...EVENTUALLY REBOUNDING TO NORMAL LEVELS
FOR THE WEEKEND.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE SLOWLY MOVES OFFSHORE THROUGH TUESDAY.

VFR WITH LIGHT S-SW FLOW TONIGHT AT MOST TERMINALS. OUTLYING 
TERMINALS COULD HAVE MVFR VSBY LATE TONIGHT INTO THE EARLY DAYLIGHT 
HOURS...AND KGON COULD FLUCTUATE BETWEEN MVFR AND IFR LATE TONIGHT 
AS IT OFTEN DOES AT THIS TIME OF YEAR UNDER A MOSTLY CLEAR SKY WITH 
LIGHT ONSHORE FLOW. 

VFR AFTER 12Z TUE. POSSIBLE LIGHT WEST/SOUTHWEST WIND IN THE 
MORNING. BETTER CHANCE FOR SEA BREEZE DEVELOPMENT AT THE USUAL 
TIMES...15Z-16Z KBDR/KGON...16Z-17Z JFK...AND 17-18Z AT 
KISP/KLGA/KHPN.

     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: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS.  

KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS.  

KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS.  

KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS. 

KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS.  

KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE 
TERMINAL FORECAST FOR DETAILS.  

.OUTLOOK FOR 00Z WED THROUGH FRI...
.TUE NIGHT-WED...PRIMARILY VFR. ISOLATED TSTM NW OF THE NY METRO 
LATE. 
.WED NIGHT-THU...SLOW MOVING COLD FROPA. BRIEF MVFR OR LOWER CONDS
IN SCT-NUMEROUS SHOWERS/TSTMS. 
.THU NIGHT-SAT...VFR.

&&

.MARINE...
A RELAXED PRESSURE GRADIENT WILL KEEP WINDS TO 15 KT OR LESS AND
SEAS 4 FT OR LESS ON THE OCEAN WATERS AND 1 FT OR LESS ON THE
REMAINDER OF THE WATERS AROUND LONG ISLAND THROUGH TUESDAY. THE
EXCEPTION WILL BE POTENTIAL FOR COASTAL JET AND A BRIEF PERIOD OF
15 TO 20 KT WINDS ACROSS THE WESTERN OCEAN WATERS AND ADJACENT
NEARSHORE WATERS LATE TUE AFT/EVE.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WINDS AND SEAS WILL INCREASE 
APPROACHING SMALL CRAFT ADVISORY LEVELS OF 25 KT AND 5 FT SEAS WED
AFTERNOON AND NIGHT.

STRONG SW FLOW WED-WED NIGHT AHEAD OF THE COLD FRONT COULD SEE
OCNL GUSTS UP TO 25 KTS...AND SHOULD SEE SEAS AROUND 5 FT ON THE
OCEAN WATERS. ONCE THE FRONT PASSES THURS...HIGH PRESSURE BUILDS
IN...ALLOWING FOR SUB-SCA CONDITIONS TO FORM ACROSS ALL WATERS BY
THURS NIGHT. SUB-SCA CONDITIONS THEN LAST THROUGH THE COMING
WEEKEND.

&&

.HYDROLOGY...
DRY INTO TUESDAY MORNING...THEN ISOLD CONVECTION COULD BRING
LOCALIZED AMOUNTS UP TO A FEW TENTHS OF AN INCH TUESDAY
AFTERNOON/EVENING MAINLY TO AREAS N/W OF NYC.

LATE WED THROUGH THU WILL BE THE NEXT CHC OF A SIGNIFICANT RAINFALL 
WITH THE POTENTIAL FOR 1/4 TO 1/2 INCH WITH THE APPROACH OF A SLOW 
MOVING COLD FRONT. A FEW HEAVY SHOWERS AND TSTMS COULD PRODUCE BRIEF 
HEAVY DOWNPOURS WITH ISOLATED AMOUNTS OF UP TO AROUND 1 INCH.

&&

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

&&

$$
SYNOPSIS...MMD/SEARS
NEAR TERM...MMD
SHORT TERM...MMD
LONG TERM...SEARS
AVIATION...GOODMAN
MARINE...GC/MALOIT
HYDROLOGY...GC/MALOIT






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