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Area Forecast Discussion
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000
FXUS61 KOKX 191731
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1231 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS IN FROM THE WEST AND MOVES OVER THE NORTHEAST
INTO EARLY NEXT WEEK. A SERIES OF LOW PRESSURE SYSTEMS WILL THEN
AFFECT THE REGION THROUGH THE MID-WEEK PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CHASING STRATUS/STRATI-CU. GRAVITY WAVE FEATURE CONTINUES TO
PROPAGATE SOUTHWEST AT A 70 DEGREE ANGLE INTO THE NORTHWEST FLOW.

MOST SUNNY SKIES WILL SPREAD INTO WESTERN LONG ISLAND AND NEW YORK
CITY. SENT A "NOW" FOR THIS.  

THINKING THAT CLOUDS RETURN IN WAKE OF THE SUBSIDENCE OF THE
GRAVITY WAVE CONTINUES TO PROPAGATE SSW. 

WITH A 25 DEGREE SUN ANGLE (WINTER SOLSTICE IS SUNDAY 603 PM) AND
THE EXPECTED CLOUD COVER - HAVE LOWERED TEMPS TO THOSE OF THE
LATEST LAMP.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
FOR TONIGHT...UNCERTAINTY REMAINS WITH THE STRATUS...THUS LOW
TEMPS MAY ONCE AGAIN BE OFF BY 5 DEGREES OR MORE. BASED ON 12Z
NAM...IT APPEARS SUFFICIENT CLOUDS WILL REMAIN...THUS HAVE TRENDED
TEMPS UP.

OTHERWISE...WITH HIGH PRESSURE CONTINUING TO BUILD INTO THE
REGION...WINDS WILL FURTHER LOWER.  

FOR SATURDAY...SAME SCENARIO HERE WITH HIGH PRESSURE CONTINUING TO 
BUILD IN. THIS DAY WILL FEATURE LOWER MAX TEMPS THOUGH BECAUSE OF 
LIMITED VERTICAL MIXING AND CLOUDS. THE WINDS IN THE LOW LEVELS WILL BE 
TRANSITIONING TO LIGHT N-NE FLOW...HELPING TO ADVECT IN SOME COOLER 
AIR. MAX TEMPS AGAIN WERE A BLEND OF GMOS/MET/MAV GUIDANCE AND UP TO 
3-4 DEGREES COOLER ALONG THE COAST THAN THE PREVIOUS DAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS HIGH PRESSURE IN THE VICINITY OF MAINE SAT NIGHT SLOWLY SHIFTS 
EAST THROUGH MONDAY...MOISTURE STREAMS INTO THE TRI STATE AREA FROM 
OFF THE WATERS. DURING SATURDAY NIGHT...THIS MOISTURE WILL BE 
SHALLOW...SUPPORTING ONLY LIGHT/VERY LIGHT PCPN. SLIGHT CHC POPS FOR 
ROUGHLY THE SE HALF OF THE CWA. MID LEVELS WILL PROBABLY BE DRY WITH 
A LACK OF ICE NUCLEI. THERE IS HOWEVER A CHANCE THAT THE COLDEST 
TEMPERATURE IN THE SATURATED LAYER CLOSER TO THE SURFACE WILL BE 
COLD ENOUGH TO SUPPORT ICE CRYSTALS FOR LIGHT SNOW. WOULD BE MORE 
CONFIDENT FOR SNOW AS A PCPN TYPE IF THE LOW LEVEL FLOW WAS MORE 
VEERED TO THE EAST (SEA SALT AS NUCLEI)...BUT IN ANY CASE...OVERALL 
CHANCES OF PCPN ARE LOW. HAVE GONE WITH A MIX OF LIGHT 
SNOW/RAIN/FREEZING RAIN DEPENDING ON SURFACE TEMPS.

MID LEVELS MOISTEN SUNDAY MORNING WITH A SHORTWAVE PASSING 
THROUGH...SO FREEZING RAIN IS PROBABLY OUT OF THE EQUATION BY THIS 
TIME. SLIGHT CHC OF LIGHT SNOW OR RAIN THEREFORE FOR SUNDAY.

POPS INCREASE MONDAY...MAINLY IN THE AFTERNOON...AS A WAVE OF LOW 
PRESSURE FORMS ALONG A STALLED BOUNDARY NEAR CAPE HATTERAS AND 
PUSHES NORTH. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW IN THE 
MORNING...THEN A CHANCE OF RAIN IN THE AFTERNOON AS THERMAL PROFILES 
BECOME TOO WARM FOR ANYTHING ELSE. WILL ALSO NEED TO MONITOR FOR THE 
POSSIBILITY OF MINOR COASTAL FLOODING STARTING WITH THE MONDAY 
MORNING HIGH TIDE CYCLE. WINDS WILL NOT BE PARTICULARLY STRONG 
LEADING UP IT...BUT THEY WILL BE ENE FOR SOME TIME AND TIDES WILL BE 
ON THE HIGHER SIDE ASTRONOMICALLY AS THERE IS A NEW MOON ON SUNDAY.

FOR TUES AND WEDS...A MUCH STRONGER LOW PRESSURE SYSTEM AFFECTS THE 
AREA. LOOKS LIKE A PRIMARY LOW CENTER MOVES ACROSS THE GREAT LAKES 
WHILE A SECONDARY LOW CENTER FORMS BEFORE PASSING NEARBY WEDS 
EVENING. THIS STILL LOOKS LIKE AN ALL-RAIN EVENT. HAVE CAPPED POPS 
AT 50% FOR TUES DUE TO UNCERTAINTY WITH NORTHWARD ADVANCEMENT OF THE 
WEAKENING INITIAL LOW THAT HAD BEEN APPROACHING FROM THE CAROLINA 
COAST. MORE CONFIDENCE IN RAINFALL DURING WEDS AS THE SECONDARY LOW 
CENTER OF THE STRONGER STORM SYSTEM PASSES NEARBY.

MINOR STREET FLOODING IS POSSIBLE DURING WEDS/WEDS EVENING. STILL A
LOW CHANCE OF CONVECTION ENHANCING THE RAINFALL AS SOME ELEVATED
INSTABILITY IS FORECAST BY BOTH GFS AND ECMWF. WINDS WILL PROBABLY
BE THE BIGGER CONCERN WITH A TIGHTENING PRESSURE GRADIENT AND A
DECENT LOW LEVEL JET PASSING THROUGH SOME TIME ON WEDS
AFTERNOON/EVENING. A WIND ADVISORY COULD EVENTUALLY BE NEEDED FOR
SOME AREAS.

RIGHT NOW IT APPEARS THAT PCPN WILL BE OVER BY CHRISTMAS MORNING. 
HOWEVER...WITH A FAIRLY STRONG WESTERLY FLOW...LAKE EFFECT RAIN/SNOW 
SHOWERS COULD REACH THE NW ZONES. NEAR-WIND ADVISORY CRITERIA COULD 
STILL BE MET. TEMPERATURES ON CHRISTMAS MOSTLY 40-45.

&&

.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/... 
LOW PRESSURE WILL MOVE FURTHER EAST ACROSS THE CANADIAN MARITIMES
AS HIGH PRESSURE MOVES EAST ACROSS NEW ENGLAND BY 12Z SAT. LOW END
VFR EXPECTED THROUGH THIS EVENING WITH CIGS MAINLY 030-040FT UNTIL
22Z. LOW CHC OF BRIEF MVFR CIGS AT KISP. NAM FCST SOUNDINGS
SUGGEST LOW LEVEL MOSITURE BECOMES MORE WIDESPREAD LATE TONIGHT
AND SATURDAY WHICH MAY PRODUCED MVFR CONDITIONS AT TIMES
ESPECIALLY AT THE COAST.

WINDS 320-350 DEGREES MAGNETIC AT SPEEDS OF 10-15KT WITH GUSTS TO 
ARND 20KT UNTIL 22Z THEN BECOMING LIGHT AND DECREASING TO LESS THAN 
10 KT OVERNIGHT. SATURDAY...EXPECT LIGHT N-NE WINDS LESS THAN 10 KT.

     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 EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT  

KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT.

KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT. 

KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT. 

KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT. 

KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED EXCEPT FOR 
TIMING OF MVFR LATE TONIGHT. 

.OUTLOOK FOR 18Z SAT THROUGH WED...
.SAT NIGHT...MVFR CIGS POSSSIBLE. LIGHT EAST TO NORTHEAST WINDS.
.SUNDAY...MVFR CIGS. LIGHT NORTHEAST WINDS. 
.MON...MVFR OR LOWER POSSIBLE IN E-SE FLOW. CHC OF RAIN.
.MON NIGHT-TUE...IFR LIKELY AT TIMES IN RAIN...CIGS AND VSBYS. E-SE 
WINDS 10-20 KT. 
.TUE NIGHT AND WED...HIGH IMPACT EVENT POSSIBLE...IFR LIKELY WITH 
HEAVY RAIN AND GUSTY SE WINDS 25KT+ SHIFTING TO SW LATE WED.

&&

.MARINE...
HIGH PRESSURE GRADUALLY BUILDING IN FROM THE WEST THROUGH
SATURDAY. AS LOW PRESSURE OVER THE MARITIMES RACES TO THE NORTHERN
LATITUDES...A STEADY DECREASE IN THE PRESSURE GRADIENT OCCUR AND SURFACE
WINDS DECREASE IN RESPONSE.

OVERALL...SUB SCA CONDITIONS SHOULD PREVAIL THROUGH SATURDAY.

TRANQUIL CONDITIONS CONTINUE THROUGH THE REST OF THE WEEKEND. WINDS 
AND SEAS BUILD ON MONDAY WITH A TIGHTENING PRESSURE GRADIENT. SCA 
CONDS THEN LIKELY FOLLOW MON NIGHT AND TUES.

&&

.HYDROLOGY...
DRY WEATHER IS FORECAST THROUGH SATURDAY WITH ONLY SLIGHT CHANCES
OF PCPN SATURDAY NIGHT AND SUNDAY. NO HYDRO IMPACTS EXPECTED INTO
EARLY NEXT WEEK.

1/4 TO 1/2 INCH OF RAIN IS POSSIBLE MONDAY AFTERNOON THROUGH TUESDAY 
AS LOW PRES PASSES SOUTH OF LONG ISLAND. NO HYDROLOGICAL IMPACTS 
EXPECTED.

RAIN ON WEDNESDAY/WEDS NIGHT MAY AVERAGE 1-2 INCHES ACROSS THE 
REGION. MINOR STREET FLOODING IS POSSIBLE.

&&

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

&&

$$
SYNOPSIS...JC/JM
NEAR TERM...TONGUE
SHORT TERM...JM/TONGUE
LONG TERM...JC
AVIATION...IRD
MARINE...JM/TONGUE
HYDROLOGY...JC/JM






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