762  
FXUS61 KOKX 112110 CCA  
AFDOKX  
 
AREA FORECAST DISCUSSION...CORRECTED  
NATIONAL WEATHER SERVICE NEW YORK NY  
410 PM EST TUE DEC 11 2018  
   
SYNOPSIS
 
 
A COLD FRONT FROM THE GREAT LAKES MOVES THROUGH TONIGHT. HIGH  
PRESSURE THEN BUILDS IN FROM THE NORTH FOR WEDNESDAY INTO WEDNESDAY  
NIGHT. A WEAK UPPER LEVEL DISTURBANCE PASSES ON THURSDAY. A  
FRONTAL SYSTEM AND ASSOCIATED LOW PRESSURE WILL THEN IMPACT THE  
AREA OVER THE WEEKEND. CANADIAN HIGH PRESSURE BUILDS IN FOR EARLY  
NEXT WEEK.  
 

 
   
NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
 
 
LIGHT SW FLOW AND DECREASING CLOUDS HEADING INTO THE EARLY  
EVENING AHEAD OF AN APPROACHING COLD FRONT FROM THE GREAT LAKES.  
THE CENTRAL LOW PRESSURE ASSOCIATED WITH THE COLD FRONT  
APPROACHING WILL BE INCREASING, ESSENTIALLY WEAKENING WITH TIME.  
THERE IS A STRONG SHORTWAVE ASSOCIATED WITH THIS MOVING ACROSS  
ALOFT TONIGHT. CLOUDS ARE EXPECTED TO INCREASE AGAIN THIS  
EVENING AHEAD OF THIS FEATURE.  
 
SOME MESOSCALE MODELS ARE DEPICTING SOME WEAK ECHOES OF  
REFLECTIVITY ACROSS EASTERN LONG ISLAND AND SOUTHEAST CT FOR  
THIS EVENING. SOME LARGER SCALE MODELS DO SHOW SOME VERY LIGHT  
PRECIPITATION NEAR THE SOUTH FORK AND TO THE EAST OVER THE  
ATLANTIC THIS EVENING. WITH THE FORCING AND MORE MOISTURE  
AVAILABLE, WENT WITH SLIGHT CHANCE POPS FOR SNOW SHOWERS,  
CHANCE OF SNOW FLURRIES ACROSS MAINLY THE EASTERN HALF OF THE  
REGION FOR THIS EVENING DURING THE PASSAGE OF THE FRONT.  
 
BEHIND THE FRONT, WINDS WILL BECOME NW AND INCREASE. THE GREATER  
MIXING WITHIN THE BOUNDARY LAYER WILL MITIGATE RADIATIONAL  
COOLING. A BLEND OF MET AND MAV GUIDANCE WAS USED FOR LOWS  
TONIGHT, SHOWING A RANGE FROM THE UPPER TEENS TO NEAR 30.  
 

 
   
SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/
 
 
HIGH PRESSURE BUILDS IN WEDNESDAY INTO WEDNESDAY NIGHT FROM THE  
NORTH WITH RIDGING ALOFT. THE WINDS WILL EVENTUALLY SWITCH FROM  
NW WEDNESDAY TO EAST FLOW WEDNESDAY NIGHT. CLOUDS ARE MINIMAL  
WEDNESDAY WITH THE RIDGING AND SUBSIDENCE. CLOUDS INCREASE  
WEDNESDAY NIGHT AHEAD OF AN APPROACHING UPPER LEVEL LOW FROM THE  
GREAT LAKES.  
 
TEMPERATURES WERE A BLEND OF MET/MAV/GMOS FOR HIGHS WEDNESDAY  
(UPPER 30S TO LOWER 40S) AND A BLEND OF NAM12/MET/MAV FOR LOWS  
WEDNESDAY NIGHT (UPPER TEENS TO NEAR 30). WEDNESDAY NIGHT LOWS  
USED A BLEND THAT KEPT COASTAL SECTIONS RELATIVELY WARMER DUE TO  
THE MORE ONSHORE EASTERLY FLOW.  
 

 
   
LONG TERM /THURSDAY THROUGH TUESDAY/
 
 
RIGHT OFF THE BAT, MODELS HAVE TRENDED FARTHER SOUTH WITH A  
NORTHERN BRANCH CLOSED LOW THAT DAMPENS ACROSS THE REGION ON  
THURSDAY AS IT RUNS OVER TOP A BUILDING EAST COAST RIDGE. HAVE  
INTRODUCED A VERY LOW CHANCE OF LIGHT SNOW AND/OR FLURRIES,  
WITH THE BEST CHANCE BEING ACROSS THE WESTERN HALF OF THE  
FORECAST AREA (LOWER HUDSON VALLEY, NE NJ, NYC). GEFS AND SREF  
PLUMES SHOW THE UPPER END OF THIS EVENT BEING A TENTH OR TWO OF  
AN INCH OF SNOWFALL. THIS COUPLED WITH TEMPERATURES ABOVE FREEZING  
SHOULD RESULT IN MINIMAL TO NO IMPACTS.  
 
THERE ARE STILL SIGNIFICANT UNCERTAINTIES WITH THE FRONTAL  
SYSTEM AND ASSOCIATED LOW THAT WILL IMPACT THE AREA OVER THE  
WEEKEND. THE MAIN FEATURE OF INTEREST IS THE TRACK OF THE  
SOUTHERN BRANCH CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI  
VALLEY, WHICH HINGES ON THE INTERACTION OF MULTIPLE NORTHERN  
BRANCH SHORTWAVES, BOTH PRECEDING AND FOLLOWING THE SYSTEM.  
THERMALLY, GUIDANCE REMAINS IN AGREEMENT THAT IT SHOULD BE AN  
ALL RAIN EVENT. THE GFS THOUGH WHICH IS MUCH FARTHER NORTH THAN  
THE ECMWF AND NOT AS FAST AS THE GGEM WITH THE UPPER LOW DOES  
LINGER PRECIPITATION INTO SUNDAY. A MARGINALLY COLD ENOUGH  
AIRMASS IN THE GFS SCENARIO COULD RESULT IN SOME MIXING ACROSS  
THE INTERIOR.  
 
RAIN FROM THIS SYSTEM WILL LIKELY WORK INTO THE AREA LATE  
FRIDAY AND CONTINUE INTO SATURDAY. THE OVERALL EVOLUTION AND  
TIMING OF THIS SYSTEM WILL ALSO DICTATE HOW MUCH OF A PLAYER IT  
COULD BE ON SUNDAY, BUT EMPHASIS AT THIS TIME IS ON THE FIRST  
HALF OF THE WEEKEND.  
 
COLD ADVECTION ON THE BACKSIDE OF THE DEPARTING LOW SUNDAY INTO  
TUESDAY WILL BRING TEMPERATURES BACK TO SEASONABLE LEVELS.  
 

 
   
AVIATION /20Z TUESDAY THROUGH SUNDAY/
 
 
HIGH PRESSURE WILL GRADUALLY WEAKEN OVER THE AREA. A COLD FRONT  
WILL MOVE ACROSS THE REGION TONIGHT.  
 
MAINLY VFR THROUGH THE TAF PERIOD. THERE IS A LOW CHANCE OF SOME  
BROKEN CLOUDS AROUND 3000 FT 00Z WITH THE COLD FRONTAL PASSAGE.  
 
LIGHT SOUTH-SOUTHWEST WINDS WITH SLOWLY TURN TO THE NORTHWEST  
TONIGHT IN RESPONSE TO THE COLD FRONT.  
 
NY METRO ENHANCED AVIATION WEATHER SUPPORT...  
 
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT FORECASTS,  
CAN BE FOUND AT: HTTP:/WWW.WEATHER.GOV/ZNY/N90  
 
KJFK TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
 
KLGA TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
 
KEWR TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
 
KTEB TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
 
KHPN TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
 
KISP TAF COMMENTS: SOME BROKEN CLOUDS AROUND 3000 FT MAY LAST  
BEYOND 20Z.  
   
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY
 
   
WEDNESDAY
 
VFR.   
THURSDAY
 
BECOMING MVFR LATE.   
FRIDAY
 
VFR/MVFR TO START, THEN SUB-VFR CONDITIONS LIKELY LATE  
IN RAIN.   
SATURDAY AND SUNDAY
 
IFR LIKELY IN RAIN.  
 

 
   
MARINE
 
 
INITIAL CONDITIONS ON WATERS ARE BELOW SCA CRITERIA BUT BEHIND  
A COLD FRONT TONIGHT, WILL HAVE INCREASED WINDS AND OCEAN SEAS.  
THE OCEAN WILL REACH SCA CRITERIA LATE TONIGHT INTO WEDNESDAY,  
FIRST FOR THE OCEAN WEST OF MORICHES INLET AND A FEW HOURS  
LATER FOR THE OCEAN EAST OF MORICHES INLET. SCA FOR WEST OF FIRE  
ISLAND INLET AND BETWEEN FIRE ISLAND INLET AND MORICHES INLET  
GOES FROM 05Z-17Z WEDNESDAY AND THE SCA FOR MORICHES INLET TO  
MONTAUK POINT GOES FROM 07Z-20Z WEDNESDAY. THE OCEAN SEAS OF  
NEAR 5 FT LAST A LITTLE LONGER FARTHER EAST ON THE OCEAN.  
CONDITIONS ARE FORECAST TO SUBSIDE BELOW SCA FOR THE OCEAN  
WEDNESDAY NIGHT. FOR NON-OCEAN WATERS, BELOW SCA CONDITIONS ARE  
FORECAST THROUGH WEDNESDAY NIGHT.  
 
A FRONTAL SYSTEM AND ASSOCIATED LOW PRESSURE WILL APPROACH THE  
AREA FRIDAY NIGHT THROUGH SATURDAY. SCA MAY BE NEEDED BY LATE  
FRIDAY NIGHT INTO SATURDAY. MUCH UNCERTAINTY INTO SUNDAY ON  
EXACT PLACEMENT OF THIS FRONTAL SYSTEM. WOULD GENERALLY EXPECT  
CONDITIONS TO SLOWLY IMPROVE FOR THE LATTER HALF OF THE WEEKEND,  
ALTHOUGH OCEAN SEAS MAY REMAIN ELEVATED.  
 

 
   
HYDROLOGY
 
 
NO SIGNIFICANT WIDESPREAD LIQUID EQUIVALENT AMOUNTS EXPECTED  
THROUGH FRIDAY.  
 
POTENTIAL REMAINS FOR A MODERATE TO HEAVY RAINFALL EVENT FRIDAY  
NIGHT INTO SATURDAY WITH AN INCH OR MORE.  
 

 
   
EQUIPMENT
 
 
NYC CENTRAL PARK WINDS ARE OUT OF SERVICE UNTIL FURTHER NOTICE.  
LOSS OF DATA IS DUE TO A SEVERED CABLE. PARTS ARE ON ORDER.  
 
NYC NOAA WEATHER RADIO STATION KWO35 (162.55 MHZ) WILL REMAIN OFF  
THE AIR FOR AN EXTENDED PERIOD OF TIME.  
 

 
   
OKX WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
NY...NONE.  
NJ...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST  
WEDNESDAY FOR ANZ353-355.  
SMALL CRAFT ADVISORY FROM 2 AM TO 3 PM EST WEDNESDAY FOR  
ANZ350.  
 

 
 

 
SYNOPSIS...JM/DW  
NEAR TERM...JM  
SHORT TERM...JM  
LONG TERM...DW  
AVIATION...BC  
MARINE...JM/DW  
HYDROLOGY...JM/DW  
EQUIPMENT...  
 
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