736  
FXUS61 KOKX 061338  
AFDOKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW YORK NY  
938 AM EDT MON JUL 6 2015  
   
SYNOPSIS
 
 
WEAK HIGH PRESSURE BUILDS OFFSHORE TODAY. A WARM FRONT APPROACHES  
FROM THE SOUTHWEST TONIGHT...THEN MOVES INTO THE TRI-STATE ON  
TUESDAY. A COLD FRONT APPROACHES FROM THE WEST TUESDAY  
NIGHT...THEN TRACKS ACROSS THE AREA WEDNESDAY INTO WEDNESDAY  
NIGHT. THE FRONT STALLS JUST TO THE SOUTH ON THURSDAY AS A WEAK  
WAVE OF LOW PRESSURE MOVES ALONG IT. HIGH PRESSURE BUILDS LATE  
WEEK AND INTO NEXT WEEKEND.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
NO SIGNIFICANT CHANGES TO FCST FOR THE MID MORNING UPDATE. DID  
LOWER CLOUD COVER FCST AMOUNTS BASED ON OBSERVATIONS AS MOST  
CIRRUS IS THIN. WILL TAKE UNTIL LATE THIS AFTN TO THICKEN. TEMP  
FCST SEEMS FINE.  
 
OTHERWISE, A DEEP LAYERED RIDGE HAS ITS AXIS SLOWLY CROSS  
THE AREA TODAY. ASSOCIATED SUBSIDENCE SHOULD BE SUFFICIENT TO KEEP  
THINGS DRY. HOWEVER AN ISOLATED SHOWER OR SPRINKLE CANNOT BE  
COMPLETELY RULED OUT OVER FAR W/SW ZONES THIS AFTERNOON (HRRR  
SUGGESTING CENTRAL NJ).  
 
FOR HIGHS TODAY A BLEND OF MIXING DOWN FROM 975-875 HPA PER BUFKIT  
SOUNDINGS...ECS/MET/MAV GUIDANCE...AND NAM 2-METER TEMPERATURES  
WAS USED. HIGHS SHOULD BE NEAR TO SLIGHTLY BELOW NORMAL.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/
 
 
AS DEEP LAYERED RIDGE CONTINUES TO SLIDE OFFSHORE...SHOULD  
MOISTEN LOW LEVELS SUFFICIENTLY TO WARRANT SLIGHT CHANCE TO  
SLIGHT CHANCE POPS OVER MAINLY THE NW 1/2 OF THE CWA LATE TONIGHT  
IN RESPONSE TO WEAK LOW LEVEL WARM ADVECTION. FOR LOWS TONIGHT...A  
BLEND OF MAV/ECS/MET GUIDANCE AND NAM 2-METER TEMPERATURES WAS  
USED...WITH VALUES FORECAST TO BE AROUND 5 DEGREES ABOVE NORMAL.  
 
FORCING AHEAD OF 700-500 HPA SHORTWAVE THAT MOVES INTO THE REGION  
LATE TUESDAY WARRANTS LIKELY POPS OVER THE NW 1/3 OF THE CWA AND  
CHANCE POPS ELSEWHERE.  
 
NOTING FORECAST CAPES GENERALLY OF 1000-1500 J/KG - SLIGHTLY LOWER  
OVER E LONG ISLAND/FAR SE CT...SHOWALTER INDICES FORECAST TO BE  
MAINLY 0 TO 2 INDICATING LOW LEVEL INSTABILITY AS WELL WARRANTS  
A CHANCE OF THUNDER AS WELL. HOWEVER WITH BULK 0-6 KM SHEAR OF  
ONLY 20-25 KT...RISK OF STRONG TO SEVERE STORMS IS FAIRLY LOW BUT  
CANNOT 100 PERCENT BE RULED OUT.  
 
FOR HIGHS TUESDAY USED A BLEND OF ECS/MET/MAV GUIDANCE...WITH NAM  
2-METER TEMPERATURES AND A MIX DOWN FROM 975 TO 900 HPA PER BUFKIT  
SOUNDINGS. HIGHS SHOULD BE A FEW DEGREES ABOVE NORMAL.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
 
 
A TROUGH OF LOW PRESSURE LIFTS TO THE NORTH TUESDAY NIGHT AND  
WEDNESDAY AS SFC COLD FRONT APPROACHES FROM THE WEST. THIS FRONT  
WILL BE NEARLY PARALLEL TO UPPER STEERING FLOW...SO IT WILL BE SLOW  
TO MOVE THROUGH ON WEDNESDAY. MODEL TIMING IS SIMILAR WITH FRONTAL  
PROGRESSION EAST.  
 
ANY LEFTOVER SHOWERS/TSTMS TUESDAY NIGHT DEPART OR WEAKEN. MOS TEMPS  
ARE CLOSE...AND SEASONABLY WARM READINGS ARE EXPECTED.  
 
THE COLD FRONT REMAINS OVER THE AREA LATE WEDNESDAY...AND PROBABLY  
CLEARS THE EASTERN ZONES BY MIDNIGHT. WILL MAINTAIN HIGH CHANCE  
COVERAGE FOR NOW...WITH SCATTERED SHOWERS/TSTMS WEDNESDAY. HEAVY  
RAIN IS POSSIBLE WITH THIS SLOW MOVING ACTIVITY...WITH PW OVER 2  
INCHES ALONG THE FRONT. THE CONCERN FOR HEAVY RAIN AND TRAINING OF  
CELLS COULD LEAD TO AT LEAST MINOR URBAN/SMALL STREAM FLOODING.  
 
MOST MODEL SOLUTIONS FORECAST THE FRONT TO SETTLE TO THE SOUTH  
THURSDAY...WITH SOME TIMING DIFFERENCES NOTED WITH A WAVE OF LOW  
PRESSURE RIDING ALONG IT. BELIEVE THE LOW PASSES TO THE SOUTH BY  
THURSDAY OR THURSDAY NIGHT...WITH WEAK HIGH PRESSURE BUILDING IN  
BEHIND IT.  
 
WILL MAINTAIN LOW CHANCES FOR SHOWERS THURSDAY INTO FRIDAY...WITH A  
DRY FORECAST THEREAFTER...OR UNTIL POSSIBLY LATER SUNDAY AS NEXT  
FRONT APPROACHES.  
 
TEMPS SHOULD AVERAGE RIGHT AROUND NORMAL LEVELS THROUGH THE PERIOD.  
BLENDED FORECAST DATABASE WITH NEW GRIDDED MOS AND WPC GUIDANCE.  
 

 
   
AVIATION /14Z MONDAY THROUGH FRIDAY/
 
 
WEAK HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY. A WARM FRONT  
WILL APPROACH FROM THE SOUTHWEST TONIGHT.  
 
VFR INTO EARLY THIS EVENING.  
 
WITH 2ND NIGHT OF ONSHORE FLOW AND A FAVORABLE S-SE WIND DIRECTION  
AHEAD OF THE APPROACHING WARM FRONT...IFR CONDS SHOULD DEVELOP  
MAINLY AFTER MIDNIGHT. LIFR EXPECTED OVERNIGHT AT KGON/KISP/KBDR  
AND CANNOT RULE IT OUT FOR KJFK.  
 
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: WIND DIRECTION MAY VARY BETWEEN 150 AND 180  
TRUE THROUGH THE AFTERNOON.  
 
KLGA FCSTER COMMENTS: WIND DIRECTION BECOMES SE AFTER 15Z.  
 
KEWR FCSTER COMMENTS: WIND DIRECTION MAY VARY BETWEEN 150 AND 180  
TRUE THROUGH THE AFTERNOON.  
 
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH  
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.  
 
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.  
 
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.  
 
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.  
   
OUTLOOK FOR 12Z TUE THROUGH FRI
 
   
TUE...CHANCE OF TSTMS WITH MVFR OR LOWER CONDITIONS AT TIMES
 
 
ESPECIALLY FROM NYC METRO NORTH/WEST.   
TUE NIGHT
 
MVFR/IFR CONDS LIKELY IN FOG.   
WED
 
CHANCE OF TSTMS WITH MVFR OR LOWER CONDITIONS AT TIMES.    
THU-FRI
 
CHANCE OF SHOWERS WITH MVFR OR LOWER CONDITIONS  
AT TIMES.  
 

 
   
MARINE
 
 
A RELAXED PRESSURE GRADIENT OVER THE REGION WILL KEEP WINDS 10 KT  
OR LESS THROUGH TUESDAY...WITH THE EXCEPTION OF 10-15 KT WINDS  
WITH OCCASIONAL GUSTS TO 20 KT IN THE NY BIGHT REGION TUESDAY  
AFTERNOON DUE TO THE SEA BREEZE. SEAS WILL REMAIN BELOW SCA  
LEVELS THROUGH TUESDAY AS WELL.  
 
PATCHY FOG COULD IMPACT THE WATERS LATE TONIGHT AND TUESDAY  
MORNING...BRING VISIBILITIES TO 1 TO 3 NM...AND POSSIBLY BELOW 1  
NM AT TIMES.  
 
SOUTHERLY FLOW PERSISTS AHEAD OF A SLOW MOVING COLD FRONT TUESDAY  
NIGHT AND WEDNESDAY. THEN AS THE FRONT PASSES NEARBY AND  
STALLS...WINDS SHOULD LIGHTEN AS THEY SHIFT TO THE NW BRIEFLY.  
 
WITH A WEAK PRESSURE GRADIENT IN PLACE...THE WINDS MAY SHIFT BACK  
AROUND TO THE S/SW THURSDAY.  
 
AS A WAVE OF LOW PRESSURE MOVES ALONG THE FRONT LATER THURSDAY AND  
THURSDAY NIGHT...RELATIVELY LIGHT WINDS MAY BECOME  
VARIABLE...DEPENDING ON THE EXACT TRACK OF THIS LOW. OVERALL...SUB  
SCA CONDITIONS ARE ANTICIPATED FOR THE MID TO LATE WEEK PERIOD.  
 
OCEAN SEA FORECASTS WERE BASED ON FORECAST DATABASE AND NEW WAVE  
WATCH OUTPUT...WHICH SEEMED QUITE REASONABLE. WIND CLIMATOLOGY WAS  
THE BASIS FOR SEA/WAVE FORECAST FOR THE NON OCEAN WATERS SURROUNDING  
LONG ISLAND.  
 

 
   
HYDROLOGY
 
 
GENERALLY AROUND 1/4 INCH OR LESS OF RAIN IS EXPECTED LATE  
TONIGHT AND TUESDAY. WITH HIGHEST AMOUNTS GENERALLY W OF THE  
HUDSON RIVER. HOWEVER...WITH PRECIPITABLE WATERS FORECAST TO BE  
BETWEEN 1.75-2 INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY  
RAINFALL WITH ANY STRONGER CONVECTION. LOCALIZED MINOR FLOODING  
OF URBAN AND POOR DRAINAGE AREAS WOULD BE POSSIBLE IF THIS WERE TO  
OCCUR.  
 
HEAVY DOWNPOURS WITH SLOW MOVING SHOWERS/THUNDERSTORMS ARE POSSIBLE  
WEDNESDAY INTO WEDNESDAY EVENING. AS SUCH...AT LEAST LOCALIZED URBAN  
AND POOR DRAINAGE FLOODING...WITH A LOW CHANCE OF FLASH  
FLOODING...IS A POSSIBILITY WEDNESDAY. WILL CONTINUE TO HIGHLIGHT  
THIS IN THE HWO FROM FAIRFIELD AND NASSAU COUNTIES ON  
WEST...INCLUDING NYC.  
 

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

 
 

 
SYNOPSIS...MALOIT/PW  
NEAR TERM...  
SHORT TERM...MALOIT  
LONG TERM...PW  
AVIATION...GOODMAN  
MARINE...MALOIT/PW  
HYDROLOGY...MALOIT/PW  
 
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