

679 

AGNT40 KWNM 311442

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

1042 AM EDT WED AUG 31 2016



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT

.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.



THE SAT IMG HAS INDC A RIDGE ACROSS THE NRN WATERS. THE

OBSERVATIONS INLUDING AN EARLIER ASCAT PASS SHOW HIGH WINDS OVER

THE FAR SRN WATERS AND THEY RANGE BETWEEN 5 AND 15 KT OVER MOST OF

THE REGION. AT 12Z A HIGH PRES RIDGE ACROSS THE NRN WATERS WITH A

STNRY FRONT ACROSS THE CENTRAL WATERS. TD EIGHT OVER THE SRN

WATERS NEAR 35.5N 73.1W IS MOVING NE AT 13 KT. FOR LATEST

INFORMATION ON TD EIGHT SEE THE NHC ADVISORY. TD NINE IS IN THE

GULF OF MEXICO AND CONTINUE TO MONITOR IT CLOSELY WITH LATEST

INFORMATION BY THE NHC. THE SEAS ARE HIGHER OVER THE SRN WATERS

AND ALSO IN THE AREAS AROUND TD 8 WITH PEAKS TO 7 AND 11 FT

RESPECTIVELY. THE NWW3 FITS WELL WITH THE OBSERVED SEAS PATERRN

BUT IS UNDERDONE AROUND THE TD 8 AREA. THE ECMWFWAVE HAS ALSO

INITIALIZED WELL WITH THE SEAS PATTERN BUT IS ALSO UNDERDONE NEAR

TD 8. WILL STAY WITH NWW3 FOR THIS UPDATE AND WILL MAKE

ADJUSTMENTS MOSTLY AROUND THE TD 8.



THE MODELS GFS/ECMWFHR/CMC/UKMETHR HAVE A GENERALLY DECENT

INITIALIZATION WITH THE 12Z OBSERVATIONS AND THEY AGREE WELL IN

THE EARLY STAGES OF TD EIGHT. THE DIFFERENCES ARE QUITE LARGE IN

THE EXTENDED PERIOD ESPECIALLY WITH TD NINE. INITIALLY THE GFS AND

ECMWF ARE VERY CLOSE BUT DIFFERENCES BECOME NOTICEABLE AFTER

02/12Z AS GFS AND ECMWF BEGIN TO DIVERGE AND THEY ALSO DIFFER IN

WINDS SPEED WITH GFS BEING MORE AGRESSIVE. OTHERWISE WILL

COMPROMISE WINDS TO FIT THE OFFICIAL TRACKS OF THE T.D 8 AND 9.

WILL START OFF WITH GFS AND THEN ECMWF WITH ADJUSTMENTS WHERE

NECESSARY.



-----------------------------------------------------------------

PREVIOUS DISCUSSION...



OVER THE SHORT TERM...IN REGARDS TO T.D. 8...THE 00Z GFS/GEM/GEFS

MEAN ALL FCST SMLR TRACKS (WITH THE T.D. TRACKING NE ACRS THE

CNTRL/NERN NT2 WTRS TODAY INTO EARLY THU AFTERNOON) THAT ARE IN

LINE WITH THE LATEST NHC FCST TRACK...BUT SLIGHTLY SLOWER. THE 00Z

UKMET/ECMWF TRACKS ARE SMLR BUT SLIGHTLY FURTHER S. THEREFORE DO

NOT ANTICIPATE NHC MAKING ANY MAJOR CHNGS IN THEIR NEXT FCST

ADVSRY OTHER THAN PRHPS TO SLIGHTLY SLOW DOWN THE SYSTEM. IN THE

WAKE OF THIS T.D. THE 00Z MDLS WITH TIMING DIFFERENCES FCST

ANOTHER DVLPG SFC LOW TO FORM OFF THE SE COAST WED NITE...THEN

TRACK NE ACRS THE NT2 WTRS THU/THU NITE. THE 00Z GFS/GEM ARE MR

PROGRESSIVE WITH THIS DVLPG LOW THAN THE 00Z UKMET/ECMWF. OVERALL

WULD FAVOR A COMPROMISE 00Z GFS/ECMWF SOLUTION FOR THIS SECOND

DVLPG SFC LOW. THEREFORE TO MAINTAIN CONTINUITY WITH T.D. 8 WL

CONT TO USE OUR PREV OFFICIAL WIND GRIDS FOR TODAY INTO THU. THEN

LATE THU/THU NITE WL TRANSITION TO A 50/50 BLEND OF THE 00Z GFS

30M AND 00Z ECMWF BL WINDS AS A COMPROMISE FOR THE SECOND SFC LOW.



IN THE LONG RANGE...THE FOCUS THEN SHIFTS TO T.D. 9 NOW IN THE

GULF OF MEXICO. VS ITS PREV 18Z RUN...THE 00Z GFS FCSTS A SMLR

STEADY NE TRACK ACRS THE SRN/CNTRL NT2 WTRS FRI THRU SAT

NITE...BUT THEN BY FCSTG A WEAKER UPR LOW TO CAPTURE THE SYSTEM AS

IT TRANSITIONS INTO BCMG POST-TROPICAL THE 00Z GFS FCSTS ITS LOW

TO PERFORM A CYCLONIC LOOP FARTHER E TWDS GEORGES BANK SUN/SUN

NITE. THE 00Z GEM/UKMET IN GNRL FCST TRACKS SMLR TO THE 00Z GFS

FRI THRU SAT NITE...BUT THEN BY FCSTG STRONGER CLOSED UPR LOWS

CAPTURING THE SYSTEM THEY BOTH FCST THEIR SFC LOWS TO CYCLONICALLY

LOOP FURTHER W THAN THE GFS INTO THE NT2 WTRS OFF CP COD BY LATE

SUN NITE. THE 00Z ECMWF FCST TRACK OVERALL IS VERY SMLR TO THE 00Z

GFS FRI INTO SUN...BUT THEN LATE SUN/SUN NITE AGAIN DUE TO A

STRONGER UPR LOW PERFORMS A CYCLONIC LOOP FURTHER W THAN THE 00Z

GFS...BUT NOT AS FAR NW AS THE 00Z GEM/UKMET. THEREFORE WITH NOT

PARTICULAR HIGH FCST CONFIDENCE WOULD FAVOR A BLENDED 00Z

GFS/ECMWF FCST TRACK FRI INTO SUN...BEFORE FAVORING THE 00Z ECMWF

TRACK LATE SUN/SUN NITE AS A COMPROMISE. BUT OF COURSE WL HAVE TO

WAIT FOR THE NEXT NHC ADVSRY BEFORE MAKING ANY FINAL DECISIONS.



.SEAS...AGAIN TO MAINTAIN CONTINUITY WITH T.D. 8 WL CONT TO USE

OUR PREV FCST WAVE GRIDS FOR TODAY INTO THU. THEN SINCE A BLENDED

00Z GFS/ECMWF SOLUTION WL BCM FAVORED WL POPULATE WITH A 50/50

BLEND OF THE 00Z WAVEWATCH III AND 00Z ECMWF WAM FOR LATE THU/THU

NITE. THEN DEPENDING ON THE NEXT NHC ADVSRY ON T.D. 9 WL LKLY

BLEND THE 00Z WAVEWATCH III/00Z ECMWF WAM WITH THE PREVIOUS

OFFICIAL WAVE GRIDS FRI INTO SUN NITE.



.EXTRATROPICAL STORM SURGE GUIDANCE...N/A. 





.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

.ANZ805...GEORGES BANK WEST OF 68W...

     GALE POSSIBLE SUN.

     STORM POSSIBLE SUN NIGHT INTO MON. 

.ANZ900...GEORGES BANK EAST OF 68W...

     GALE POSSIBLE SUN NIGHT INTO MON. 

.ANZ810...SOUTH OF NEW ENGLAND...

     GALE POSSIBLE SUN.

     STORM POSSIBLE SUN NIGHT INTO MON. 

.ANZ815...SOUTH OF LONG ISLAND...

     GALE POSSIBLE SUN INTO SUN NIGHT. 



.NT2 MID ATLC WATERS...

.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...

     TROPICAL STORM POSSIBLE SAT NIGHT INTO SUN. 

     STORM POSSIBLE SUN NIGHT INTO MON. 

.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...

     TROPICAL STORM TONIGHT.

     TROPICAL STORM POSSIBLE SAT NIGHT INTO SUN. 

     STORM POSSIBLE SUN NIGHT.

.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...

     TROPICAL STORM TONIGHT INTO THU. 

     TROPICAL STORM POSSIBLE SUN.

     STORM POSSIBLE SUN NIGHT INTO MON. 

.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...

     TROPICAL STORM TONIGHT INTO THU. 

     TROPICAL STORM POSSIBLE SAT NIGHT INTO SUN. 

     STORM POSSIBLE SUN NIGHT.

     GALE POSSIBLE MON.

.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES LIGHT...

     TROPICAL STORM POSSIBLE SAT.

.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...

     TROPICAL STORM POSSIBLE SAT.

.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...

     TROPICAL STORM TONIGHT.

     TROPICAL STORM POSSIBLE SAT INTO SAT NIGHT. 

.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS...

     TROPICAL STORM POSSIBLE FRI NIGHT INTO SAT. 

.ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR...

     TROPICAL STORM POSSIBLE FRI NIGHT INTO SAT. 

.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...

     TROPICAL STORM POSSIBLE SAT.

.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...

     TROPICAL STORM POSSIBLE FRI INTO FRI NIGHT. 



$$



.FORECASTER MUSONDA/VUKITS. OCEAN PREDICTION CENTER.

