498  
FXUS61 KOKX 231635  
AFDOKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW YORK NY  
1135 AM EST SUN NOV 23 2014  
   
SYNOPSIS
 
 
A WARM FRONT SLOWLY APPROACHES FROM THE SOUTHWEST THROUGH THIS  
EVENING...THEN LIFTS TO THE NORTH LATE TONIGHT AND MONDAY MORNING.  
A COLD FRONT FOLLOWS BEHIND IT MONDAY NIGHT...THEN A SECONDARY  
COLD FRONT PASSES ON TUESDAY. WEAK HIGH PRESSURE THEN BUILDS IN  
TUESDAY NIGHT. AN AREA OF LOW PRESSURE OFF THE SOUTHEASTERN  
SEABOARD WEDNESDAY MORNING...TRACKS NORTHEAST TO THE CANADIAN  
MARITIME PROVINCES BY THURSDAY EVENING. HIGH PRESSURE THEN BUILDS  
IN FROM THE WEST INTO FRIDAY...FOLLOWED BY A ALBERTA CLIPPER  
SYSTEM IMPACTING THE AREA SATURDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
SPRINKLES/LGT SHWRS ACROSS UPSTATE NY CORRESPOND TO ENHANCED MID  
LVL THETAE ON THE 12Z NAM. INCLUDED SCHC FOR A FEW SPRINKLES WRN  
PORTIONS OF THE CWA FOR THIS. BULK OF ANY MEASUREABLE RAIN SHOULD  
BE MAINLY N OF THE CATSKILLS PER STLT...RADAR AND MODELS.  
 
MIXED OUT TEMPS FROM H975 AND ADDED A FEW DEGREES THIS  
AFTN...RAISING FCST HIGHS BY SEVERAL DEGREES. FULL MIXING BASED  
ON THE 12Z SOUNDING WOULD YIELD LWR 60S...WHICH IS NOT ENTIRELY  
OUT OF THE QUESTION TIL SFC WINDS BACK.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/
 
 
THE DEEP LAYERED RIDGE LIFTS TO THE NORTHEAST THIS  
EVENING...ALLOWING FOR LOW-MID LEVEL MOISTURE TO QUICKLY BUILD IN  
BEHIND IT. WITH DIFFLUENT FLOW DEVELOPING ALOFT AND PASSAGE OF A  
60-70 KT LOW LEVEL JET...EXPECT MODERATE...TO POSSIBLY LOCALLY  
HEAVY...RAINFALL OVERSPREADING THE ENTIRE AREA AFTER MIDNIGHT  
AHEAD OF THE SURFACE-850 HPA WARM FRONT.  
 
THERE IS SUFFICIENT ELEVATED INSTABILITY OVER EASTERN ZONES...WITH  
SHOWALTER INDICES FORECAST TO BETWEEN 0 AND 2...ALONG WITH THE  
AFOREMENTIONED LOW LEVEL JET...THAT HAVE CONTINUED WITH A  
SLIGHT CHANCE OF THUNDER THERE.  
 
PRECIPITATION SHOULD TAPER OFF TO -SHRA BY LATE MONDAY MORNING AS  
THE WARM FRONTS LIFT TO THE NE. REFER TO THE HYDROLOGY SECTION OF  
THE AFD FOR DETAILS ON AMOUNTS AND ANY POTENTIAL IMPACTS.  
 
ALSO WITH THE PASSAGE OF THE AFOREMENTIONED LOW LEVEL JET...THERE  
COULD BE ISOLATED WIND GUSTS OF 40-50 MPH IN ANY EMBEDDED  
CONVECTION...WITH THE BEST CHANCE OVER EASTERN ZONES LATE  
TONIGHT/MONDAY MORNING - AND DAMAGING WIND GUSTS CANNOT BE 100  
PERCENT RULED OUT. IT SHOULD END UP QUITE WINDY ONCE IN THE WARM  
SECTOR MONDAY AFTERNOON AND EVENING...WITH GUSTS UP TO 30-40 MPH.  
ISOLATED STRONGER GUSTS ARE POSSIBLE...HOWEVER CONFIDENCE IN THERE  
OCCURRENCE AND AREAL COVERAGE IS NOT HIGH ENOUGH TO WARRANT A WIND  
ADVISORY AT THIS TIME.  
 
FOR LOWS TONIGHT A BLEND OF MAV/MET/ECS GUIDANCE AND NAM 2-METER  
TEMPERATURES WAS USED...WITH VALUES FORECAST TO BE AROUND 10-15  
DEGREES ABOVE NORMAL. EXPECT THE LOWS TO OCCUR IN THE  
EVENING...THEN TEMPERATURES TO RISE INTO THE 50S  
OVERNIGHT...EXCEPT MID-UPPER 40S FAR NW ORANGE COUNTY.  
 
RECORD HIGHS QUITE POSSIBLY WILL BE SET ON MONDAY AT MANY  
LOCATIONS...WITH THE REGION SOLIDLY IN THE WARM SECTOR IN THE  
AFTERNOON. THE MAIN QUESTION IS HOW MUCH CLEARING WILL OCCUR ONCE  
THERE. FOR NOW APPEARS SHOULD BE SUFFICIENT TO SUPPORT HIGHS  
AROUND 15-20 DEGREES ABOVE NORMAL. THIS IS CONSISTENT WITH A BLEND  
OF MAV/MET/ECS GUIDANCE WITH A MIX DOWN FROM 975-950 HPA PER  
BUFKIT SOUNDINGS AND NAM 2-METER TEMPERATURES. REFER TO THE  
CLIMATE SECTION OF THE AFD FOR DETAILS.  
 
SHOULD HAVE SUFFICIENT LOW LEVEL MOISTURE TO SEE AN ISOLD-SCT SHRA  
AHEAD OF THE COLD FRONT MONDAY EVENING. THEN CLEARING IN ITS WAKE.  
FOR LOWS MONDAY NIGHT A BLEND OF MAV/MET/ECS GUIDANCE AND NAM  
2-METER TEMPERATURES WAS USED...WITH VALUES FORECAST TO BE AROUND  
15 DEGREES ABOVE NORMAL.  
 
TUESDAY WILL FEATURE SW FLOW ALOFT...AND AS CURRENTLY FORECAST TO  
BE ABSENT ANY SHORTWAVES EMBEDDED IN THE FLOW...IT SHOULD BE DRY.  
FOR HIGHS USED A BLEND OF MIXING DOWN FROM 900-850 HPA PER BUFKIT  
SOUNDINGS WITH MAV/MET GUIDANCE AND NAM 2-METER TEMPERATURES.  
HIGHS SHOULD BE A FEW DEGREES ABOVE NORMAL.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
 
 
THERE ARE STILL DIFFERENCES BETWEEN THE MODELS...BUT NOW THE  
RESPECTIVE ENSEMBLE MEANS GENERALLY SUPPORTING THE GFS (THOUGH THE  
ECMWF ENSEMBLE MEAN IS FARTHER W). WITH THE GFS AND CMC TRENDING  
STRONGER (AROUND 10 MB DEEPER THAN LAST NIGHT) AND FARTHER  
WEST...HAVE OPTED TO USE A ECMWF/GFS BLEND AS THERE IS INCREASING  
EVIDENCE THAT A SOLUTION IN BETWEEN THE TWO SEEMS THE MOST  
REASONABLE.  
 
UNTIL ALL THE KEY PLAYERS...INCLUDING ENERGY STILL OUT OVER THE  
PACIFIC ARE RESOLVED...THE EXACT NATURE OF INTERACTION BETWEEN A  
NORTHERN STREAM CLIPPER AND A POSITIVELY TILTED TROUGH OVER THE E  
CENTRAL PORTION OF THE COUNTRY BY MIDWEEK IS STILL UNCERTAIN - SO  
THE FORECAST WILL LIKELY CHANGE TO SOME DEGREE. FOR NOW THOUGH THE  
FOLLOWING IS WHAT APPEARS MOST LIKELY - THAT A FAIRLY DECENT...BUT  
NOT OVERLY STRONG LOW SHOULD TRACK JUST EAST OF THE 40N/70W  
BENCHMARK WEDNESDAY EVENING.  
 
THE BLEND WOULD SUGGEST THAT LIGHT RAIN COULD REACH LONG ISLAND  
AND MAYBE FAR SE CT LATE TUESDAY NIGHT POSSIBLY MIXED WITH SNOW.  
THE PRECIPITATION SHOULD THEN SPREAD NW FAIRLY QUICKLY WEDNESDAY  
MORNING...POSSIBLY STARTING AS A BRIEF PERIOD OF SNOW INLAND  
BEFORE TURNING TO ALL RAIN. AS THE LOW NEARS THE BENCHMARK  
WEDNESDAY EVENING...ENOUGH LOW LEVEL COLD AIR SHOULD COME IN  
BEHIND IT TO CHANGE ALL PRECIPITATION TO SNOW DURING WEDNESDAY  
NIGHT...FROM NW TO SE...THROUGHOUT THE CWA. THE EXACT TIMING OF  
THIS IS UNCERTAIN. PRECIPITATION SHOULD TAPER OFF FROM SW TO NE  
THURSDAY MORNING...UNLESS THE DEFORMATION AXIS LINGERS OVER THE  
AREA...WHICH IS SUGGESTED BY THE ECMWF. FOR THIS REASON JUST WENT  
WITH SLIGHT CHANCE POPS THROUGH THE DAY.  
 
THE ECMWF TAKEN BY ITSELF WOULD SUGGEST THE POSSIBILITY OF WARNING  
LEVEL SNOWS TO THE W/N OF NYC...WHILE THE GFS SOLUTION SUGGESTS  
THE POSSIBILITY OF WARNING LEVEL SNOWS FARTHER EAST. GIVEN  
THIS...THERE IS A 30 PERCENT CONFIDENCE OF REACHING WARNING LEVEL  
SNOW ACCUMULATIONS ACROSS THE CWA...SO WILL REFLECT THIS IN THE  
HWO. FORTUNATELY IT LOOKS LIKE MOST...IF NOT ALL...ACCUMULATING  
SNOW WILL OCCUR MAINLY WEDNESDAY NIGHT SO THE IMPACT ON THE BULK  
OF PRE-THANKSGIVING TRAVEL SHOULD BE MINIMIZED.  
 
ZONAL THEN SW FLOW BUILDS IN BEHIND THE SYSTEM INTO FRIDAY...THEN A  
WEAK ALBERTA CLIPPER PASSES TO THE N ON SATURDAY...POSSIBLY  
LEADING TO COASTAL DEVELOPMENT NEAR CAPE COD. BASED ON THIS HAVE  
SLIGHT CHANCE POPS IN OVER EASTERN ZONES FRIDAY NIGHT AND  
SATURDAY...WITH THE CLIPPER ITSELF LIKELY PASSING TO FAR N TO  
BRING ANY PRECIPITATION BY ITSELF UNTIL THE COASTAL LOW FORMS.  
 
FOR TEMPERATURES TUESDAY NIGHT-SATURDAY A BLEND OF  
MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WAS USED...WITH NAM 2-METER  
TEMPERATURES BLENDED IN TUESDAY NIGHT AND GFS AND ECMWF 2-METER  
TEMPERATURES BLENDED IN WEDNESDAY AND WEDNESDAY NIGHT.  
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE LONG TERM.  
 

 
   
AVIATION /18Z SUNDAY THROUGH FRIDAY/
 
 
HIGH PRES REMAINS OFFSHORE TODAY. A WARM FRONT APPROACHES AND PASSES  
THROUGH TONIGHT.  
 
VFR THROUGH AROUND 03-05Z MONDAY. RAIN WITH IFR DEVELOPS SHORTLY  
THEREAFTER.  
 
SW WINDS WILL GENERALLY AVERAGE AROUND 10 KT OR LESS INTO THE  
AFTERNOON. WINDS AT KBDR/KGON MAY BACK MORE TO THE SOUTH LATE  
THIS AFTN. OTHERWISE...ALL TERMINALS BACK TO THE SOUTH AT SOME  
POINT BY MIDNIGHT AND INCREASE OVERNIGHT.  
 
LOW LEVEL WIND SHEAR IS LIKELY LATE TONIGHT INTO EARLY MONDAY  
MORNING WITH WINDS AT 2000FT RANGING FROM 50-65 KT.  
   
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY
 
   
MONDAY
 
IMPROVING CONDS. MORNING SHRA. SOUTH WINDS AROUND 20 KT  
WITH 25-35 KT GUSTS.   
MONDAY NIGHT
 
MAINLY VFR. WINDS SHIFT TO THE WEST AT 10-15 KT.   
TUESDAY
 
VFR. WSW WINDS 15-20 KT WITH 20-30 KT GUSTS.   
TUESDAY NIGHT
 
DIMINISHING WINDS. SUB-VFR CIGS POSSIBLE LATE.   
WEDNESDAY-WEDNESDAY NIGHT
 
LOW TO MODERATE CONFIDENCE FORECAST  
WITH PASSAGE OF COASTAL LOW. ACCUMULATING SNOW THREAT POSSIBLE FOR  
THE INTERIOR...BUT ACCUMULATING SNOW COULD OCCUR CLOSER TO THE COAST  
DURING WED NIGHT BASED ON TRACK OF LOW. STRONG WINDS POSSIBLE  
DEPENDING ON TRACK OF LOW AS WELL.   
THURSDAY
 
LOW CONFIDENCE FORECAST. LINGERING RAIN/SNOW SHOWERS  
POSSIBLE. STRONG WINDS POSSIBLE AS WELL.  
 

 
   
MARINE
 
 
RAN THE SCA ON THE ERN OCEAN TIL 23Z WITH SEAS STILL CLOSE TO 8 FT  
OFF MONTAUK. WINDS PICK UP LATE TONIGHT INTO MON MORNING WITH A  
TIGHTENING PRESSURE GRADIENT AND THE APPROACH AND PASSAGE OF A  
950MB LOW LEVEL JET OF 60-70KT. HAVE THEREFORE GONE WITH A GALE  
WARNING FOR THE OCEAN WATERS...EASTERN LONG ISLAND SOUND...AND THE  
LONG ISLAND BAYS LATE AT NIGHT THROUGH MONDAY AFTERNOON. SCA FOR  
THE OTHER WATERS DURING THE SAME PERIOD.  
 
ALTHOUGH WINDS DIMINISH MONDAY NIGHT...SCA CONDITIONS STILL  
PROBABLE FOR ALL WATERS THROUGH AT LEAST TUESDAY MORNING. SEAS ON  
THE OCEAN WILL TAKE LONGER THAN THIS TO SUBSIDE BELOW 5 FT. LOOKS  
LIKE BY MIDNIGHT TUESDAY NIGHT...ALL WATERS WILL BE BELOW ADVISORY  
CRITERIA.  
 
THE NEXT STORM AFFECTS THE WATERS LATE WEDS AFTERNOON THROUGH  
THURS WITH A COASTAL STORM PASSING NEARBY THE 40N/70W BENCHMARK  
WEDS NIGHT. FOR NOW...SCA CONDITIONS FORECAST...BUT THERE IS  
POTENTIAL FOR GALES. CONFIDENCE NOT HIGH AT THIS TIME.  
 

 
   
HYDROLOGY
 
 
AROUND 3/4 TO 1 INCH OF RAIN IS FORECAST FROM LATE TONIGHT THROUGH  
MONDAY. ANY LOCALLY HEAVY RAINFALL MAY RESULT IN URBAN/POOR DRAINAGE  
FLOODING LOCALLY. THE HEAVIEST RAIN WILL OCCUR DURING THE MORNING  
RUSH HOUR MONDAY MORNING...WITH THE MOST LIKELY IMPACT BEING TO  
SLOW THE COMMUTE DUE TO WET ROADS.  
 
THERE IS INCREASING POTENTIAL FOR 1/2 INCH OR MORE OF QPF TO FALL  
FROM LATE TUESDAY NIGHT INTO THURSDAY MORNING. AT THIS TIME THERE  
IS TOO MUCH UNCERTAINTY TO SPECIFY ANY IMPACT...OTHER THAN TO NOTE  
THAT SOME PORTION OF THIS SHOULD FALL IN THE FORM OF SNOW. AT THIS  
TIME IT APPEARS THAT THE BEST CHANCE OF GETTING MORE THAN 1/2 INCH  
OF QPF WOULD BE OVER LONG ISLAND AND S CT.  
 

 
   
CLIMATE
 
 
RECORD HIGH TEMPERATURES FOR MONDAY 24 NOVEMBER...  
 
LOCATION........RECORD/YEAR.....FORECAST HIGH  
 
NEWARK..............75/1979..........71  
BRIDGEPORT..........63/1979..........65  
CENTRAL PARK........73/1979..........69  
LAGUARDIA AIRPORT...68/1999..........70  
JFK AIRPORT.........63/2001*.........68  
ISLIP...............63/2001..........66  
 
* ALSO OCCURRED IN PREVIOUS YEARS  
 

 
   
OKX WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
NY...NONE.  
NJ...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EST MONDAY FOR ANZ335-  
338.  
GALE WARNING FROM 1 AM TO 6 PM EST MONDAY FOR ANZ330-340-345-  
350-353-355.  
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-  
353.  
 

 
 

 
SYNOPSIS...MALOIT  
NEAR TERM...JMC  
SHORT TERM...MALOIT  
LONG TERM...MALOIT  
AVIATION...JC/PW  
MARINE...JMC/JC/MALOIT  
HYDROLOGY...MALOIT  
CLIMATE...  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

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