FXUS61 KOKX 030553
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1253 AM EST THU DEC 3 2009

.SYNOPSIS...
DEEPENING LOW PRESSURE WILL MOVE FROM THE OHIO RIVER VALLEY THIS
EVENING TO NEAR NOVA SCOTIA THURSDAY EVENING...WITH ITS ASSOCIATED
WARM FRONT LIFTING THROUGH LATE TONIGHT...AND TRAILING COLD FRONT
CROSSING THE AREA THURSDAY MORNING INTO EARLY THURSDAY AFTERNOON.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST FROM LATE THURSDAY
THROUGH MONDAY...THEN SLIDE OFFSHORE MONDAY NIGHT AND TUESDAY.
MEANWHILE...A COASTAL LOW WILL PASS SOUTHEAST OF LONG ISLAND
SATURDAY AND SATURDAY NIGHT. A COMPLEX STORM SYSTEM WILL THEN
IMPACT THE REGION DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
STRONGEST WINDS LATE TONIGHT INTO THURSDAY MORNING...FROM NYC AND
POINTS EAST...AS 80+ KT SOUTHERLY LLJ OVER VIRGINIA EARLY THIS
MORNING WORKS NE THROUGH THE REGION. HIGHEST SUSTAINED WINDS MAY
BE WITH LLJ IN WARM SECTOR AHEAD OF TRAILING COLD FRONT...WITH
HIGHEST GUSTS IN POST-FRONTAL/POST SHORTWAVE BURST. SOLID WIND
ADVISORY CRITERIA WINDS EXPECTED AT THAT TIME.

TEMPS ARE REMAINING NEARLY STEADY ATTM AND SHOULD SLOWLY RISE AS
WINDS INCREASE OVERNIGHT...REACHING THE UPPER 50S/LOWER 60S ONCE THE
WARM FRONT GOES THROUGH LATE TONIGHT. PERHAPS A FEW MID 60S ACROSS
NY/NJ METRO.

OTHERWISE RAIN WILL CONTINUE THROUGH THE NIGHT...TAPERING OFF FROM
W TO E THURSDAY MORNING AS THE LOW PULLS AWAY. EXPECT THE HEAVIEST
RAIN OVERNIGHT AS 850 AND SURFACE WARM FRONT PUSH THROUGH THE
REGION (SEE HYDROLOGY SECTION FOR MORE DETAILS ON QPF). THERE IS
ENOUGH LOW LEVEL INSTABILITY AND FORCING AHEAD OF COLD FRONTAL
PASSAGE THAT ELEVATED THUNDER IS POSSIBLE AS WELL OVERNIGHT. FOR
NOW IT APPEARS THE ELEVATED NATURE OF THE CONVECTION AND THE LOW
LEVEL INVERSION SHOULD PRECLUDE THE MIXING DOWN OF WARNING
CRITERIA WINDS (THOUGH THIS CANNOT BE COMPLETELY RULED OUT).

SKY CONDITIONS SHOULD FAIRLY RAPIDLY CLEAR OUT...AND WINDS DIE
DOWN THURSDAY EVENING...WITH MAINLY CLEAR SKY CONDITIONS AND
LIGHT WINDS EXPECTED THURSDAY NIGHT.

HIGHS THURSDAY WILL OCCUR IN THE MORNING (AROUND 60-MID
60S...EXCEPT MID TO UPPER 50S FAR NW)...THEN EXPECT SLOWLY FALLING
TEMPERATURES THURSDAY AFTERNOON BEHIND THE COLD FRONT. FOLLOWED
MET GUIDANCE.

WITH MAINLY CLEAR SKY CONDITIONS AND LIGHT WINDS...TEMPERATURES
SHOULD FALL OF FAIRLY RAPIDLY THURSDAY NIGHT...USED THE COLDER OF
MET/MAV NUMBERS FOR LOWS.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
FORECAST COMPUTER MODELS SHOW AN UPPER LEVEL SHORT WAVE TROUGH 
ROTATING AROUND A LARGE CUTOFF POLAR LOW BETWEEN THE UPPER GREAT 
LAKES AND JAMES BAY CANADA.

BECAUSE THERE ARE DIFFERENCES IN THE AMPLITUDE AND TIMING OF THIS 
ROTATING TROUGH...THIS IS A LOW CONFIDENCE FORECAST FOR A LIGHT 
PRECIPITATION EVENT SATURDAY AFTERNOON AND NIGHT.

LOW PRES IS FORECAST TO DEVELOP OF THE SE COAST SAT MORNING AND 
TRACK OFFSHORE. THE NAM MODEL SHOWS THIS LOW SLOWER AND FURTHER 
WEST. THE GFS MODEL SHOWS THIS LOW FASTER AND FURTHER EAST. WILL 
CONT WITH A CHANCE OF POPS...RAIN/SNOW ALONG THE COAST AND SNOW INLAND 
SAT AFTERNOON AND CHANCE OF SNOW THROUGHOUT THE AREA SAT NIGHT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
PRECIP WINDS DOWN EARLY AM SUN AS THE SFC LOW LIFTS OFF TO THE 
NORTHEAST. HIGH PRESSURE BUILDS INTO THE REGION LATER SUN INTO 
MON...WITH DRY CONDITIONS PREVAILING THROUGH TUE. THE NEXT CHANCE OF 
PRECIP ARRIVES LATE ON WED IN ASSOCIATION WITH A SYSTEM MOVING OUT 
OF THE OHIO AND MISSISSIPPI VALLEYS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LOW MVFR/IFR CONDS...LOWER END IN HEAVY RAIN...EARLY THIS MORNING.
ISOLATED THUNDERSTORMS POSSIBLE FROM AROUND 08Z TO 12Z AHEAD OF
COLD FRONT.

MARGINAL LOW LEVEL WIND SHEAR IS ALSO POSSIBLE BETWEEN 08Z AND
12Z AS WINDS INCREASE TO NEAR 65KT AT 2KFT...MAINLY FROM NYC
TERMINALS EAST RIGHT.

RAIN COMES TO AND END WITH RAPID IMPROVEMENT TO VFR AFTER COLD
FRONTAL PASSAGE...BETWEEN 11Z AND 14Z. 

WINDS WILL BE THE MAIN ISSUE WITH SUSTAINED SE/S WIND OF 20 TO 30
KT POSSIBLE ALONG NYC AND EASTERN TERMINALS FROM AROUND 08Z TO
12Z. A BRIEF BURST OF 40 KT WIND GUSTS POSSIBLE IN WAKE OF COLD
FRONTAL PASSAGE THIS MORNING AS WINDS SHIFT FROM S TO SW.

GUSTY WSW FLOW (30 TO 35 KT) DURING THE DAY...WITH A PERIOD OF BKN
VFR INSTABILITY CU POSSIBLE ACROSS WESTERN TERMINALS DURING LATE
MORNING INTO EARLY AFTERNOON.

WINDS AND GUSTS GRADUALLY SUBSIDE THIS EVENING.

OUTLOOK 06Z FRIDAY THROUGH MONDAY... 
TONIGHT THROUGH FRI NIGHT...VFR. 
LATE SAT AND SAT NIGHT MVFR TO IFR IN RAIN AND SNOW. 
SUN TROUGH MON...VFR.

&&

.MARINE...
ON TRACK FOR SOLID GALE FROM TONIGHT INTO THU. THINK LOW LEVEL
INVERSION WILL PREVENT MIXING OF STORM FORCE WINDS FROM
ALOFT...WITH LATEST FCST SOUNDINGS SHOWING VERY LITTLE WIND SPEED
VARIABILITY IN THE LOWEST LEVELS (MAYBE 5 KT)...SO WHILE AN
ISOLATED GUST TO STORM FORCE IS POSSIBLE... ESPECIALLY OVER THE
WATERS AROUND EASTERN LONG ISLAND...DO NOT THINK IT WILL BE
PREVALENT ENOUGH TO WARRANT STORM WARNINGS. WINDS DIE DOWN BELOW
GALE FORCE DURING THE DAY ON THU FROM W TO E. EXPECT SMALL CRAFT
ADVISORIES TO REPLACE THE GALES ON ALL WATERS ONCE THE GALE
CONDITIONS HAVE ENDED. EXPECT WINDS TO FALL BELOW SCA LEVELS ON
ALL WATERS BY THE END OF THURSDAY NIGHT (LASTLY ACROSS THE EASTERN
OCEAN WATERS).

STRONG SE-S WINDS TONIGHT...THEN SW WINDS ON THU WILL BUILD SEAS
ON THE OCEAN WATERS TO 7 TO 13 FT AND 4 TO 7 FT ON THE SOUND BY
MORNING...BOTH HIGHEST EAST. SEAS SHOULD FALL BELOW SCA CRITERIA
ON THE SOUND BY LATE THU...BUT REMAIN ABOVE SCA CRITERIA ON THE
OCEAN WATERS THU NIGHT.

SCA CONDITIONS ARE POSSIBLE EARLY FRI...THEN SEAS SUBSIDING LATER
IN THE DAY. SEAS MAY BUILD ABOVE SCA CRITERIA AGAIN ON THE OCEAN
SAT NIGHT-SUN MORNING AS A COASTAL LOW PASSES SOUTH/EAST OF THE
LOCAL AREA. THEN QUIET CONDITIONS SHOULD FOLLOW FOR SUNDAY
AFTERNOON AND BEYOND AS HIGH PRESSURE BUILDS INTO THE REGION.

&&

.HYDROLOGY...
EXPECT AROUND 12 HOURS OF RAIN TONIGHT...LOCALLY HEAVY AT
TIMES...ESPECIALLY IN ASSOCIATION WITH ANY ISOLATED CONVECTION.
LOOK FOR 1 TO 1.5 INCHES OF RAIN...HIGHEST EAST...WITH LOCALLY
HIGHER AMOUNTS. MAIN THREAT IS FOR URBAN POOR DRAINAGE FLOODING. 

AFTER THINGS DRY OUT THURSDAY MORNING...NO OTHER SIGNIFICANT 
PRECIPITATION (0.5 INCHES OR MORE) IS EXPECTED THROUGH EARLY 
NEXT WEEK. 

A PASSING COASTAL LOW SATURDAY COULD BRING A FEW TENTHS OF AN INCH
OF LIQUID...WITH SOME OF IT FALLING AS SNOW...SO NO HYDROLOGIC
IMPACT IS EXPECTED.

&&

.TIDES/COASTAL FLOODING...
GUIDANCE WAS RUNNING 0.5 TO 1.5 FT TOO LOW THIS AFTERNOON...SO
ADJUSTING FOR THIS AND EXPECTED STORM TIMING...EXPECT MINOR
COASTAL FLOODING ALONG THE COAST OF THE SOUND AND THE BACK BAYS
OF LONG ISLAND/NYC. DEPARTURES WILL RUN ABOUT 1.5 FT ABOVE
NORMAL...WITH MODERATE FLOODING BENCHMARKS BEING APPROACHED ALONG
THE FAR WESTERN SOUND (BUT LIKELY NOT EXCEEDED DUE TO THE
RELATIVELY SHORT DURATION OF THE STRONG SE WINDS).

WITH WAVES BUILDING TO 8-10 FT AT ATLANTIC BEACHES THU...HAVE
ISSUED A HIGH SURF ADVISORY THERE...ALSO HIGHLIGHTING THE
POTENTIAL FOR BEACH EROSION.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ007>012.
     COASTAL FLOOD ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS 
     AFTERNOON FOR CTZ009>012.
NY...WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ071>081.
     COASTAL FLOOD ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS 
     AFTERNOON FOR NYZ071>081.
     HIGH SURF ADVISORY FROM 5 AM EARLY THIS MORNING TO MIDNIGHT 
     EST TONIGHT FOR NYZ075>077-080-081.
NJ...COASTAL FLOOD ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS 
     AFTERNOON FOR NJZ006.
MARINE...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ330-340-345-
     350-353-355.
     GALE WARNING UNTIL 11 AM EST THIS MORNING FOR ANZ335-338.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...NV
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...