FXUS61 KOKX 041130
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
630 AM EST FRI DEC 4 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH SUNDAY...THEN SLIDE OFFSHORE
SUNDAY NIGHT AND MONDAY. MEANWHILE...A COASTAL LOW WILL TRACK
SOUTHEAST OF LONG ISLAND SATURDAY AND SATURDAY NIGHT. A COLD FRONT
WILL CROSS THE REGION MONDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
TO THE NORTH THROUGH TUESDAY NIGHT...FOLLOWED BY A COMPLEX STORM
SYSTEM DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LOW SPINS OVER CENTRAL ONTARIO TODAY WITH SHORTWAVE SLIDING TO 
TEXAS/MEXICO BORDER...WITH REGION ON WEST SIDE OF UPPER RIDGING. 
SURFACE HIGH PRESSURE BUILDS INTO THE REGION FROM THE SW. THIS WILL 
BRING SUNNY SKIES...GIVING WAY TO HIGH CLOUDS STREAMING IN THE 
AFTERNOON. TEMPS SLIGHTLY ABOVE SEASONABLE TODAY...LOWER 50S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
UPPER LOW SLOWLY DRIFTS FROM CENTRAL ONTARIO TO CENTRAL 
QUEBEC...WITH SHORTWAVE ENERGY SLIDING FROM DEEP SOUTH EARLY 
SATURDAY TO THE MID ATLANTIC COAST BY SUNDAY MORNING. 

MODELS CONTINUE TO HAVE SOME DIFFERENCES IN SPEED OF THIS
AND TRACK SHORTWAVE ENERGY SAT INTO SUN...WHICH CONTINUES TO
PRESENT DIFFERING SOLUTIONS ON THE TRACK OF A RESULTANT COASTAL
LOW. BUT THERE HAS BEEN A DECIDED WESTWARD SHIFT IN
SOLUTIONS...MEANING A WETTER FORECAST.

EXPECTING INCREASING CLOUDS LATE TONIGHT INTO SATURDAY...BUT 
QUESTION IS HOW FAR N AND W THE PRECIP SHIELD GETS. ENSEMBLE 
SOLUTIONS AND GFS/ECMWF/CAN POINT TOWARDS MAIN PRECIP SHIELD STAYING 
OFFSHORE. OPERATIONAL NAM IS STILL WETTEST AND WARMER WESTERLY
OUTLIER...BUT ECMWF AND GGEM HAVE SHIFTED NOTICEABLY WESTWARD AS
WELL. SO CAN'T TOTALLY DISCOUNT IDEA OF NAM AS SOME RECENT COASTAL
STORMS HAVE HAD TENDENCY TO TRACK CLOSER TO THE COAST THEN
FORECAST. SO WILL ADJUST FORECAST TRACK WESTWARD...INCREASING POPS
AND QPF FROM PREVIOUS THINKING.

HIGHEST QPF TOTALS ACROSS FAR SE SECTIONS (UP TO 1/2 INCH)...TAPERING
TO UP TO 1/4 INCH INTO NYC METRO...AND UP TO AROUND 1/10TH OF AN
INCH NW OF NYC. IF WESTWARD SHIFT CONTINUES THESE AMOUNTS MAY HAVE
TO BE INCREASED.

THINGS GET FURTHER COMPLICATED BY COLD AIR FILTERING INTO THE REGION 
FROM THE NW TONIGHT INTO SAT...PRESENTING P-TYPE ISSUES FOR SAT
INTO SAT NIGHT.

MODEL THERMAL FIELDS WOULD FAVOR SNOW OVER THE NW 2/3 OF THE CWA
WITH A RAIN/SNOW MIX TRANSITIONING TO ALL SNOW OVER THE SE 1/3
(NYC/LI/SE COASTAL CONN). HOWEVER...THE BOUNDARY LAYER IS STILL WARM
FOR THIS TIME OF YEAR...SO ANY PRECIPITATION WOULD TO START AS
RAIN OVER ALL BUT FAR NW AREAS SATURDAY AFTERNOON. HIGHEST POPS
LATE SAT AFTERNOON INTO EVENING AS SHORTWAVE ENERGY
APPROACHES...WITH A GRADUAL TRANSITION TO ALL SNOW BEFORE ENDING
FROM W TO E LATER SATURDAY NIGHT.

ALTHOUGH AREAS NW OF NYC MAY SEE MAINLY SNOW...THEY MAY NOT SEE MUCH 
IN TERMS OF ACCUM DUE TO LACK OF ACTUAL PRECIP. LESS THAN AN
INCH.

ELSEWHERE THE RATE OF BOUNDARY LEVEL COOLING AND AMOUNT OF LIQUID 
EQUIVALENT WILL DETERMINE HOW MUCH SNOW FALLS. STILL QUITE A DEAL OF 
UNCERTAINTY...BUT CURRENT THINKING IS THAT DUE TO INITIALLY WARM 
BOUNDARY LAYER TEMPS AND RAIN...MOST AREAS WOULD SEE LESS THAN AN
INCH OF SLUSHY ACCUM. PERHAPS A STRIPE ACROSS SE CONN HAVING THE
BEST SHOT OF SEEING AN INCH OR TWO. IF THIS STORM DOES TRACK
CLOSER TO THE COAST...THIS 1 TO 2 INCH STRIPE MAY HAVE TO BE
EXPANDED/SHIFTED FURTHER NW INTO SW CONN AND SOUTHERN LOWER
HUDSON VALLEY.

GUSTY NORTHERLY WINDS ARE ALSO EXPECTED SAT AFTERNOON INTO SAT NIGHT 
AS LOW PRESSURE TRACKS NE...IN VICINITY OF 40/70 BENCHMARK. WILL BE A 
RAW DAY...WITH CLOUDS AND DEVELOPING PRECIP HOLDING TEMPS IN THE
UPPER 30S/LOWER 40S. 

ANY PRECIP SHOULD COME TO AN END LATE SAT NIGHT AS SHORTWAVE ENERGY 
SLIDES EAST AND LOW PRESSURE TRACKS TOWARDS THE CANADIAN MARITIMES. 
WITH COLDER AIR ADVECTING IN. WIND CHILLS SAT NIGHT MAY DROP INTO
THE LOWER 20S AND UPPER TEENS INTERIOR.

GENERALLY ZONAL UPPER FLOW ON SUNDAY...WITH SURFACE HIGH PRESSURE 
BUILDING IN FROM THE WEST. THIS SHOULD LEND TO A MOSTLY SUNNY DAY
WITH TEMPS SEVERAL DEGREES BELOW SEASONABLE...LOWER 40S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS INTO THE REGION SUN NIGHT INTO MON...WITH DRY
CONDITIONS PREVAILING. WARM ADVECTION AND RETURN FLOW SETS UP LATE
MONDAY AS A WARM FRONT LIFTS NORTH OF THE REGION. SOME HINTS OF
LIGHT PRECIP MONDAY NIGHT AND WILL KEEP SLIGHT CHANCE POPS MON
NIGHT AND TUE. SURFACE HIGH BUILDS IN FROM THE W LATER TUE AND TUE
NIGHT. LESS CONFIDENCE IN THE FCST ABOUNDS STARTING WED AS SOME
MODEL UNCERTAINTY AS TO WHETHER A SECONDARY AREA OF LOW PRES
DEVELOPS OFF HATTERAS AND ITS EVENTUAL TRACK AND STRENGTH.
PRECIPITATION TYPE AND AMOUNT WILL BE HIGHLY DEPENDENT ON THE
TRACK OF THIS SYS...AND FOR NOW WILL KEEP HIGH CHANCE POPS WED AND
WED NIGHT. COLD SURFACE HIGH BUILDS IN BEGINNING THU TO CLEAR
THINGS OUT FOR THE END OF THE WEEK.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR FORECAST THROUGH 24 HOURS. IN THE 24-36 HOUR PORTION OF THE TAF 
FOR KJFK/KEWR/KSWF...CONDITIONS BECOME A BIT MORE COMPLEX AS SUB-VFR 
CIGS POSSIBLE IN -RA.

FOR WINDS...GENERALLY A WEST-NORTHWEST FLOW AT LESS THAN 10 KT ON 
TAP THROUGH THIS EVENING. THE WIND DIRECTION MAY APPROACH 310 
DEGREES AT KEWR/KJFK/KLGA LATE THIS MORNING...BUT SHOULD STAY ABOUT 
10 DEGREES TO THE LEFT OF 310.

TONIGHT...WINDS SHIFT NORTHWEST...THEN TO THE NORTHEAST...AT 5-10 KT 
ACROSS KNYC TERMINALS. ELSEWHERE...WINDS BECOME NEARLY L/V THIS 
EVENING BEFORE GRADUALLY TURNING NORTH AND INCREASING TO 5-7 KT 
AFTER MIDNIGHT.

TAF COMMENTS (FORECASTER INSIGHT ON TIMING...CONFIDENCE...TRENDS
AND GROUND OPS)

KEWR...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KEWR HOURLY WIND FORECAST
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
     04/10Z 26008KT    
     04/11Z 26008KT    
     04/12Z 26008KT    
     04/13Z 26008KT    
     04/14Z 26008KT    
     04/15Z 26008KT    
     04/16Z 27008KT    
     04/17Z 27007KT    
     04/18Z 27007KT    
     04/19Z 27006KT    
     04/20Z 28006KT    
     04/21Z 28005KT    

KJFK...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KLGA...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KTEB...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KHPN...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KSWF...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KISP...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KBDR...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

KGON...FORECAST ON TRACK...NO UNSCHEDULED AMENDMENTS 
ANTICIPATED

OUTLOOK 12Z SAT THROUGH TUE... 
SAT-SAT NIGHT...SUB-VFR IN RAIN DURING THE DAY AND SNOW BECOMING 
LIKELY BY LATE AFTERNOON/EARLY EVENING.
SUN-TUE...VFR.

&&

.MARINE...
GUSTY NW WINDS PERSIST ACROSS THE OCEAN ZONES THIS MORNING. A SLOW 
DECREASE IN SPEED NOTED...WHICH IS IN LINE WITH CURRENT GUIDANCE. 
SEAS STILL RUNNING 4 TO 6 FT FROM SANDY HOOK EASTWARD...AND AS HIGH 
AS 8 TO 10 FT SOUTH OF MONTAUK POINT. THE CURRENT SMALL CRAFT 
DISTRIBUTION LOOKS GOOD...WITH THE WESTERN ZONES EXPIRING AT 6AM. 
THERE MAY BE A FEW RESIDUAL 5 FOOTERS IN ZONE 355 AFTER 6AM...BUT 
THE GENERAL TREND WILL BE DOWNWARD. 

HIGH PRESSURE SHOULD ALLOW FOR LIGHT ENOUGH WINDS TO ALLOW SEAS TO 
CONTINUE TO SUBSIDE TONIGHT.

THERE IS STILL SOME UNCERTAINTY IN THE TRACK OF LOW PRESSURE PASSING 
SOUTH OF LONG ISLAND SATURDAY EVENING. NONETHELESS...THE GENERAL 
PATTERN SUGGESTS WINDS VEERING TO NORTHERLY AND INCREASING AS THE 
LOW APPROACHES. IT LOOKS LIKE SOLID SMALL CRAFT CONDITIONS BY 
SATURDAY AFTERNOON LASTING THROUGH SUNDAY. SOME GUSTS TO GALE FORCE 
ARE POSSIBLE...AND A LOW END GALE EVENT IS POSSIBLE SATURDAY EVENING 
THROUGH SUNDAY...DEPENDING ON THE TRACK AND INTENSITY OF THE LOW. 

HIGH PRESSURE BUILDS IN SUNDAY...BUT WINDS AND SEAS WILL COME DOWN 
SLOWLY AS THE DEPARTING LOW CONTINUES TO DEEPEN. 

HIGH PRESSURE WILL MOVE OVER THE WATERS MONDAY THROUGH WEDNESDAY. A 
WEAK WAVE PASSING SOUTH OF THE WATERS TUESDAY SHOULD NOT PRODUCE 
SMALL CRAFT CONDITIONS.

&&

.HYDROLOGY...
UP TO 1/2 INCH OF LIQUID EQUIVALENT IS POSSIBLE WITH THE COASTAL
LOW LATE SATURDAY AND SATURDAY NIGHT...WITH MOST OF THAT FALLING
OVER SE CONN AND EASTERN LONG ISLAND...AND SOME OF THAT IN THE
FORM OF SNOW. AS A RESULT NO HYDROLOGIC IMPACT IS EXPECTED.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
     353-355.

&&

$$
SYNOPSIS...NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DW
AVIATION...MPS
MARINE...BS
HYDROLOGY...NV