

935 

AGNT40 KWNM 300023

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

823 PM 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.



UPDATE...18Z NCEP SFC ANALYSIS SHOWS T.D. EIGHT CENTERED OVER ZONE

930 IN THE SRN NT2 WTRS...WITH T.D. NINE CENTERED ABOUT 60 NM NW

OF WRN CUBA...HURCN GASTON IS CENTERED ABOUT 480 NM E OF

BERMUDA...AND A COLD FRONT EXTNDG NE TO SW ACROSS THE GULF OF

MAINE...SRN NEW ENGLAND...AND INTO NEW JERSEY. LATEST AVAILABLE

ASCAT HI-RES AND ASCAT PASSES FROM THIS MORNING SHOW AREAS OF

WINDS TO 20 KT ALONG THE ERN PART OF ZONE 930 AND IN THE GULF OF

MAINE...BUT THERE WAS NO COVERAGE OVER THE CENTRAL PART OF T.D.

EIGHT. LIGHTNING DENSITY PRODUCT DATA AT 2310Z INDICATES SCATTERED

SHOWERS AND TSTMS OVER ZONES 830/833/930 IN THE SRN NT2 WTRS.



MODELS...THE GEM LOOKS SIGNIF TOO SLOW WILL ALL OF THE MAIN

WEATHER FEATURES FOR WED THRU SAT NITE...AND IS CONSIDERED TO BE

AN OUTLYER SOLN. OTHERWISE...THE ECMWF/GFS/UKMET ARE IN GUD

OVERALL AGREEMNT ACROSS THE OFSHR WTRS FOR TONITE THRU WED

NITE...SO THE REPRESENTATIVE GFS 30M SOLN WILL BE USED FOR THIS

TIMEFRAME. THE GFS LOOKS SOMEWHAT SLOW WITH T.D. EIGHT FOR THE THU

THRU SAT NITE PERIODS...AND ALSO APPEARS TO BE TOO WEAK WITH BOTH

T.D. EIGHT AND T.D. NINE...SO WILL BE USING THE ECMWF STARTING THU

THRU THE REST OF THE FCST PERIOD. AM NOT PLANNING TO MAKE ANY

SIGNIF CHANGES TO THE CURRENT FCST TREND...UNLESS THERE ARE SIGNIF

CHANGES TO THE FCST TRACKS OF T.D. EIGHT AND/OR T.D. NINE.



SEAS...THE WNA WAVEWATCH III MDL AND ECMWF WAM BOTH INITIALIZED

REASONABLY WELL OVER THE OFSHR WTRS. IN ORDER TO BE CONSISTENT

WITH THE PREFERRED WIND GRID MDLS...WILL USE THE WNA WAVEWATCH III

FOR TONITE THRU WED NITE THEN SWITCH TO USING THE ECMWF WAM FOR

THU THRU SAT NITE.



EXTRATROPICAL STORM SURGE GUIDANCE...N/A.



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

PREVIOUS DISCUSSION...



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

LATEST OBSRERVATIONS INCLUDING ASCAT PASS ABOUT 1452Z SUGGEST

HIGHWER WINDS OVER THE SRN WATERS. THE ASCAT PASS MISSED MOST OF

THE REGION INCLUDING THE AREA AROUND TROPICAL DEPRESSION EIGHT. AT

18Z MAIN SYNOPTIC FEATURES AFFECTING THE NRN WATERS ARE STILL 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 HAS WEAKENED 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 AS A TROPICAL STORM IN THE

EXTENDED PERIOD. SEE THE NHC FOR THE LATEST ON HURCN GASTON...T.D.

EIGHT AND T.D NINE.



THE MODELS GFS/ECMWFHR/UKMETHR/CMC/NOGAPS/JMA HAVE INITIALIZED

FAIRLY WELL WITH 18Z OBSERVATIONS PATTERN BUT STILL HAVE

DIFFERENCES WITH PEAK VALUES NEAR THE CENTER OF T.D. EIGHT. 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.



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

T.D EIGHT WITH PEAK TO 10 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.



.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.

     TROPICAL STORM POSSIBLE SAT.

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

     TROPICAL STORM POSSIBLE WED NIGHT INTO THU. 

     TROPICAL STORM POSSIBLE SAT INTO SAT NIGHT. 

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

     TROPICAL STORM POSSIBLE WED NIGHT INTO THU. 

     TROPICAL STORM POSSIBLE SAT INTO SAT NIGHT. 

.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 FRI NIGHT INTO SAT. 

.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 TUE INTO TUE NIGHT. 

     TROPICAL STORM POSSIBLE FRI INTO FRI NIGHT. 

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

     TROPICAL STORM TUE NIGHT INTO WED. 

     TROPICAL STORM POSSIBLE FRI INTO SAT. 

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

     TROPICAL STORM POSSIBLE THU NIGHT INTO FRI NIGHT. 

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

     TROPICAL STORM POSSIBLE FRI INTO FRI NIGHT. 



$$



.FORECASTER SCOVIL/MUSONDA. OCEAN PREDICTION CENTER.

