

789 

AGNT40 KWNM 291448

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

1048 AM EDT MON AUG 29 2016



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

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



THE SAT IMG INDC A HIGH PRES RIDGE OVER THE NRN WATERS. THE LATEST

OBSRERVATIONS INCLUDING THE EARLIER ASCAT PASS SHOW HIGHWER WINDS

OVER THE SRN WATERS. AT 12Z MAIN SYNOPTIC FEATURES AFFECTING THE

NRN WATERS ARE HIGH PRES 1024 MB NEAR 42N49W THAT EXTENDS A RIDGE

W INTO THE NRN WATERS WITH A SECONDARY HIGH CENTER 1020 MB OVER

THE NE BALT CANYON. A STNRY FRONT LIES ACROSS THE CENTRAL WATERS

AND THE PRES GRADIENT IS FAIRLY SLACK. OVER THE SRN WATERS IS

TROPICAL DEPRESSION EIGHT. HURCN GASTON IS CENTERED ABOUT 800 NM E

OF THE SRN WATERS OR ABOUT 480 NM E OF BERMUDA. TROPICAL

DEPRESSION NINE IS SLATED TO MOVE INTO THE SRN WATERS MID WEEK.

SEE THE NHC FOR THE LATEST ON HURCN GASTON... T.D. EIGHT AND T.D

NINE. THE SEAS ARE HIGHER OVER THE SRN WATRS IN THE VICINITY OF

T.D EIGHT WITH PEAK TO 9 FT. OTHERWISE SEAS RANGE BETWEEN 3 AND 6

FT OVER THE CENTRAL AND NRN WATERS. NWW3 WAVE MODEL HAS INITALIZED

WELL WITH THE SEAS PATTERN AND SEEM TO BE DOING BETTER THAN IN THE

PREVIOUS RUNS AROUND T.D. EIGHT. WILL CONTINUE WITH NWW3. THE

GLOBAL MODELS HAVE ALSO INTIALIZED WELL BUT STILL DIFFER SLIGHTLY

NEAR THE CENTER OF THE T.D. THE MODEL WINDS APPEAR TO BE

UNDERDONE BUT ARE BETTER THAN THE PREVIOUS RUNS. WILL STAY WITH

GFS THEN APPLY TCM TOOL FOR T.D EIGHT AND T.D NINE.





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

PREVIOUS DISCUSSION...



SUMMARY...00Z NCEP SFC ANALYSIS SHOWS T.D. EIGHT CENTERED ABOUT

30 NM E OF THE SRN NT2 WTRS...WITH T.D. NINE CENTERED ABOUT 80 NM

SW OF KEY WEST...AND HURCN GASTON CENTERED ABOUT 500 NM E SE OF

BERMUDA. REFER TO LATEST NHC ADVISORIES FOR ADDITIONAL INFORMATION

ON T.D. EIGHT/T.D. NINE/HURCN GASTON. LATEST AVAILABLE ASCAT AND

ASCAT HI-RES PASSES FROM EARLIER THIS MORNING DID NOT GIVE ANY

COVERAGE OVER T.D. EIGHT...BUT DO SHOW AN AREA OF 20 KT WINDS IN

THE OUTER ZONES OF THE SRN NT2 WTRS. LIGHTNING DENSITY PRODUCT

DATA AT 0630Z SHOWS A FEW SMALL AREAS OF SCATTERED SHOWERS AND

TSTMS...INCLUDING ON THE WRN SIDE OF T.D. EIGHT.



MODELS...00Z ECMWF/GFS ARE IN GUD OVERALL AGREEMNT ACROSS THE

OFSHR WTRS DURING THE FCST PERIOD...EXCEPT THE 00Z ECMWF IS A BIT

FASTER AND STRONGER WITH T.D. NINE ON FRI AND FRI NITE. 00Z

UKMET LOOKS CLOSE TO ECMWF/GFS WITH TIMING/TRACKS OF T.D. EIGHT

AND T.D. NITE...BUT IS GENERALLY MUCH STRONGER WITH THESE SYSTEMS.

00Z GEM IS SLOWER AND SIGNIF STRONGER THAN THE OTHER MDLS WITH

T.D. NINE. LATEST NHC OFFICIAL TRACK FCSTS FOR T.D. EIGHT AND

T.D. NITE LOOK CLOSE TO THE 00Z GFS...ALTHO THE GFS IS LIKELY TOO

WEAK WITH THESE SYSTEMS AND WILL NEED TO BE BEEFED UP WHEN DOING

THE WIND GRIDS. AM PLANNING TO USE THE 00Z GFS 30M SOLN FOR THE

WIND GRIDS DURING THE FCST PERIOD...ESPECIALLY IF THERE ARE NO

MAJOR CHANGES TO THE UPCOMING FCST TRACKS FOR T.D. EIGHT AND T.D.

NINE.



SEAS...BOTH THE 00Z WNA WAVEWATCH III MDL AND THE 00Z ECMWF WAM

INITIALIZED WELL OVER THE OFSHR WTRS. IN GENERAL THE 00Z ECMWF WAM

LOOKS UNDERDONE IN THE NT2 AREA FOR TODAY INTO THU...AND THE MORE

ROBUST 00Z WNA WAVEWATCH III IS PREFERRED FOR THIS TIMEFRAME. 00Z

WNA WAVEWATCH III/ECWMF WAM LOOK DIFFERENT OVER THE SRN NT2 WTRS

FOR THU NITE THRU FRI NITE WITH THEIR HANDLING OF T.D. NINE...AND

SINCE DO NOT HAVE A PREFERRED WAVE HT MDL FOR THIS PERIOD WILL GO

WITH A 50/50 BLEND OF THE MDLS HERE AS AN ATTEMPT AT SMOOTHING OUT

THE MDL DIFFS.



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





.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

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

     TROPICAL STORM POSSIBLE WED NIGHT.

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

     TROPICAL STORM WED.

     TROPICAL STORM POSSIBLE WED NIGHT.

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

     TROPICAL STORM POSSIBLE WED NIGHT INTO THU. 

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

     TROPICAL STORM POSSIBLE WED NIGHT INTO THU. 

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

     TROPICAL STORM TUE NIGHT INTO WED. 

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

     TROPICAL STORM TUE NIGHT INTO WED. 

     TROPICAL STORM POSSIBLE WED NIGHT.

     TROPICAL STORM POSSIBLE FRI NIGHT INTO SAT NIGHT. 

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

     TROPICAL STORM TUE INTO WED. 

     TROPICAL STORM POSSIBLE FRI NIGHT.

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

     TROPICAL STORM TONIGHT INTO TUE NIGHT. 

     TROPICAL STORM POSSIBLE FRI INTO SAT. 

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

     TROPICAL STORM TONIGHT INTO WED. 

     TROPICAL STORM POSSIBLE FRI INTO SAT NIGHT. 

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

     TROPICAL STORM POSSIBLE THU NIGHT INTO SAT. 

.ANZ935...OUTER WATERS FROM CAPE FEAR TO 31N...

     TROPICAL STORM POSSIBLE FRI INTO SAT NIGHT. 



$$



.FORECASTER MUSONDA/SCOVIL. OCEAN PREDICTION CENTER.

