968  
FXUS61 KOKX 301426  
AFDOKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW YORK NY  
1026 AM EDT SAT AUG 30 2014  
   
SYNOPSIS
 
 
HIGH PRESSURE ALONG THE NEW ENGLAND COAST WILL WORK FARTHER  
OFFSHORE AS THE WEEKEND PROGRESSES. AT THE SAME TIME...LOW  
PRESSURE ACROSS THE GREAT LAKES WORKS NORTHEAST AND INTO EASTERN  
CANADA...SENDING A LOW PRESSURE TROUGH ACROSS THE AREA LATE  
SUNDAY. WEAK HIGH PRESSURE BRIEFLY RETURNS BEFORE ANOTHER COLD  
FRONT APPROACHES TUESDAY. THIS FRONT MOVES ACROSS LATE TUESDAY  
NIGHT WITH HIGH PRESSURE BUILDING BACK IN FROM THE WEST FROM MID  
TO LATE NEXT WEEK. ANOTHER COLD FRONT APPROACHES LATE NEXT FRIDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
JUST SOME MINOR ADJUSTMENTS MADE TO THE FORECAST BASED ON CURRENT  
CONDITIONS.  
 
BOTH HIGH PRESSURE ALOFT AND AT THE SFC WORK EAST OF THE AREA  
TODAY WITH A RETURN SLY FLOW AND INCREASING LOW-LEVEL MOISTURE AS  
DEW POINTS CLIMB INTO THE 60S. A SUBSIDENCE INVERSION WILL PUT A  
CAP ON ANY CONVECTION.  
 
GENERALLY LOOKING FOR MOSTLY SUNNY SKIES...ALTHOUGH SCT SC CLOUDS  
ARE FORECAST AS MOISTURE BECOMES TRAPPED UNDERNEATH THE SUBSIDENCE  
INVERSION. AS SUCH...SKIES COULD BE PARTLY CLOUDY AT TIMES.  
 
HIGH TEMPS WILL BE JUST BELOW NORMAL WITH READINGS IN THE MID TO  
UPPER 70S.  
 
WITH INCREASING SOUTHERLY FLOW...THERE IS A MODERATE RISK OF RIP  
CURRENTS THIS AFTERNOON/EVENING.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/
 
 
WARM...MUGGY CONDITIONS DEVELOP AS A SLY FLOW SENDS DEW POINTS  
THROUGH THE 60S TO AROUND 70 BY DAYBREAK SUN. THIS WILL RESULT IN  
LOWS TONIGHT WELL INTO THE 60S.  
 
MORE IMPORTANTLY....WARM ADVECTION IN A DEEP-LAYERED SW FLOW WILL  
TRANSPORT TROPICAL MOISTURE FROM THE GULF COAST STATES NORTHWARD  
INTO THE REGION WITH PW VALUES AROUND 2 INCHES SUN INTO SUN NIGHT.  
THIS COMBINED WITH DAYTIME HIGHS IN THE 80S WILL ALLOW FOR A  
DESTABILIZING AIRMASS WITH MDT-HIGH CAPES AND MARGINAL-MDT SHEAR.  
A SHORT WAVE TROF ALOFT AND A SFC TROF ACROSS EASTERN PA WILL  
LIKELY TRIGGER CONVECTION IN THE EARLY AFT WHICH WILL WORK INTO NE  
NJ/LOWER HUDSON VALLEY IN THE MID AFT...THEN INTO NYC/CT/LI IN THE  
LATE AFT/EVE HOURS. THERE IS SOME CONCERN THAT THE SFC TROF LAYS  
DOWN ACROSS AREA DURING THE NIGHTTIME HOURS WITH THE POTENTIAL FOR  
A CONVECTIVE COMPLEX AND TRAINING OF THUNDERSTORMS. THE PRIMARY  
HAZARD WOULD BE FLASH FLOODING. RIGHT NOW...THE BEST CHANCE LOOKS  
TO BE NEAR OR JUST EAST OF NYC AND ACROSS LI/COASTAL CT. THERE  
STILL REMAINS A FAIR AMOUNT OF UNCERTAINTY WITH THE DETAILS AND  
MODEL SOLUTIONS VARY WITH THE PROGRESSION OF THE SYSTEM.  
OFTEN...IN AIRMASSES DEEP IN MOISTURE LIKE THIS...SUBTLE FEATURES  
ARE ALL THAT IS NEEDED TO PROVIDE THE LIFT/FOCUS FOR HEAVY  
RAINFALL. THE REAL CHALLENGE WILL BE PINPOINTING THE LOCATION.  
SHOULD CONFIDENCE INCREASE WITH LOCATION AND TIMING...A FLOOD  
WATCH MAY ISSUED LATER TODAY.  
 
DEW POINTS WILL BE IN THE LOWER 70S SUN INTO SUN NIGHT...MAKING  
FOR A VERY MUGGY SUN NIGHT. LOWS WILL RANGE FROM THE UPPER 60S TO  
LOWER 70S.  
 

 
   
LONG TERM /MONDAY THROUGH FRIDAY/
 
 
SCATTERED CONVECTION MAINLY MON MORNING DEPENDING ON WHERE THE SFC  
TROF RESIDES. CONDITIONS ARE EXPECTED TO DRY OUT AFT/EVE WITH WEAK  
HIGH PRESSURE NOSING IN FROM THE SW. WARM...MUGGY CONDITIONS TO  
CONTINUE WITH HIGHS IN THE 80S AND DEW POINTS AROUND 70.  
 
A LITTLE STRONGER PARENT LOW IN SOUTHEAST CANADA NEAR THE GREAT  
LAKES MOVES INTO THE NORTHEAST TUESDAY NIGHT WITH AN ASSOCIATED  
COLD FRONT MOVING IN OVERNIGHT INTO WEDNESDAY MORNING. THE FRONT  
PUSHES EAST OF THE REGION WEDNESDAY WITH A WEAK HIGH BUILDING IN  
FROM THE WEST THEREAFTER THROUGH EARLY FRIDAY. ANOTHER FRONT MAY  
APPROACH FOR LATER NEXT FRIDAY.'  
 
NEXT CHANCE OF CONVECTION WILL BE TUESDAY AFTERNOON THROUGH  
TUESDAY NIGHT. MDT-HIGH CAPE ENVIRONMENT...BUT WEAKLY SHEARED.  
THIS COULD RESULT IN A FEW STRONG STORMS.  
 
FOR HIGHS THROUGH THE PERIOD....AROUND 4-7 DEGREES ABOVE NORMAL  
WITH VALUES WELL INTO THE 80S FOR THE LONG TERM PERIOD. LOWS  
GENERALLY 5-10 DEGREES ABOVE NORMAL SUNDAY NIGHT THROUGH TUESDAY  
NIGHT AND A FEW DEGREES ABOVE NORMAL WEDNESDAY NIGHT THROUGH  
THURSDAY NIGHT.  
 

 
   
AVIATION /14Z SATURDAY THROUGH WEDNESDAY/
 
 
HIGH PRES OFF THE NEW ENGLAND COAST WILL MOVE OUT TO SEA THROUGH  
TONIGHT AS A TROUGH OF LOW PRES APPROACHES FROM THE WEST.  
 
VFR WITH SCT TO BKN CU TODAY.  
 
SLY WINDS INCREASE LATE THIS MORNING INTO AFTN WITH OCNL GUSTS UP TO  
20KT POSSIBLE AFT 19Z. MVFR CIGS/BR POSSIBLE TONIGHT...BUT PCPN  
SHOULD HOLD OFF UNTIL AFT 12Z SUN.  
   
OUTLOOK FOR 12Z SUN THROUGH THU
 
   
SUN-TUE NIGHT
 
MAINLY MVFR CIGS AND VSBY WITH MULTIPLE  
ROUNDS OF SHOWERS AND TSTMS STARTING DURING THE DAY SUNDAY.   
WED-THU
 
MAINLY VFR.  
 

 
   
MARINE
 
 
SUB-ADVSY CONDS WILL PREVAIL INTO SUN. THERE IS SOME UNCERTAINTY  
WITH MIXING OVER THE WATERS SUN AFTN/EVE...WITH THE POTENTIAL FOR A  
WINDOW OF SCA GUSTS ON THE OCEAN WATERS. AM NOT CONVINCED THAT THIS  
WILL OCCUR AND THINK THE LOW LEVEL LAPSE RATES IN THE NAM OVER THE  
WATERS ARE TOO STEEP WHICH IS LEADING TO BETTER MIXING AND SCA  
GUSTS. HAVE THEM JUST UNDER 25 KT...BUT WILL RUN WITH OCNL GUSTS UP  
TO 25 KT FOR NOW.  
 
SEAS ON THE OCEAN WILL ALSO BUILD IN RESPONSE TO AN INCREASING SW  
FLOW. SINCE MARGINAL SCA SEAS ARE EXPECTED TO BEGIN LATE IN THE  
THIRD PERIOD...WILL HOLD OFF ON ISSUING HEADLINES...ESPECIALLY SINCE  
GUSTS ARE IN QUESTION. SEAS WILL LIKELY CONTINUE THROUGH SUN NIGHT  
AND FALL BACK BLO ADVSY LEVELS MON MORNING.  
 
WAVEWATCH INCREASES SEAS BACK TO SCA LEVELS MON NIGHT...BUT THINK  
THIS IS OVERDONE CONSIDERING THE WIND FIELD...SO HAVE CAPPED AT 4 FT.  
SUB-ADVSY CONDS ARE THEN EXPECTED FOR THE REMAINDER OF THE FORECAST  
PERIOD WITH A WEAK PRES GRADIENT OVER THE WATERS.  
 

 
   
HYDROLOGY
 
 
DEEP MOISTURE IN PLACE WITH TROF APPROACHING SUNDAY AND INTO THE  
REGION SUNDAY NIGHT AND MONDAY...SO ANY SHOWERS AND THUNDERSTORMS  
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY DOWNPOURS. LOCALIZED  
FLOODING THREAT WILL REMAIN WHICH WOULD VARY FROM MINOR AND POOR  
DRAINAGE TO POSSIBLY FLASH FLOODING.  
 

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

 
 

 
SYNOPSIS...DW  
NEAR TERM...DW/PW  
SHORT TERM...DW  
LONG TERM...JM/DW  
AVIATION...JC/24  
MARINE...24/PW  
HYDROLOGY...DW  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab NY Page
The Nexlab NJ Page
The Nexlab CT Page Main Text Page