

749 

AGNT40 KWNM 040138

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

938 PM EDT WED AUG 3 2016



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

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



GOES IR IMGRY INDC A FRONTAL BNDRY ACRS SRN NT2...AND THE LTST

NCEP SFC ANALYS INDC A WK WAVE TO THE SE OF CAPE FEAR. THE EARLIER

ASCAT WIND RETRIEVALS INDC UP TO 25 KT IN THE S TO SW FLOW AHEAD

OF THE FRONT...THO THE PASS IS MORE ABT 8 HOURS OLD...AND THE CRNT

SFC RPRTS INDC NO NORE THAN 15 TO 20 KT. THE 2140 UTC RSCAT

PASSINDC 25 TO 30 KT...THO THE LGTNG DENSITY PROD INDC TSTMS NR

THE HIGHER WINDS...SO THEY ARE PROBABLY CONTAMINATED. THE 18Z GFS

INDC 20 KT ACRS NT2 S OF THE FRONT...WHICH SEEMS RSNBL...AND IS NR

THE PREV FCST...SO PLANNING ON STARTING OFF WITH THAT. THE

DATA/MODELS ALSO INDC 20 KT IN NE NT2...IN THE CAA W OF THE DVLPG

LOW JUST E OF THE AREA...SO PLANNING ON STARTING WITH 20 KT THERE

AS WELL. IN ADDITION...WL MAINTAIN PREV MENTION OF SHOWERS AND

TSTMS WITH THE CONVECTION ALONG THE FRONT.



THE 12Z/18Z GLBL AND RGNL MODELS INDC THE AFOREMENTIONED FRONTAL

WAVE WL DRIFT E OF THE AREA TNGT INTO THU NGT. THE 12Z/18Z GFS IS

IN RSNBLY GUD AGRMT WITH THE TRACK OF THE 12Z ECMWF/UKMET...THO

THE GFS IS A LTL STGR. THE NAM TAKES THE LOW NE...AND THE GEM IS

STGR THAN THE GFS...WHILE IT SPLITS IT INTO TWO PIECES. THE PREV

FCST FAVORED THE GFS SOLN...WHICH HAS NOT CHANGED MUCH IN THE 18Z

RUN...SO PLANNING ON STICKING WITH IT FOR THE UPDATE PKG.



IN THE EXTENDED...THE GFS AGREES WELL WITH THE ECMWF ON THE NEXT

FRONT THAT MOVES OFF THE NEW ENGLAND AND MID ATLC COAST SAT INTO

SAT NIGHT...AND MOVES SE THROUGH THE AREA SUN INTO MON. THE GEM

AND UKMET AGREE WELL TOO...AND WITH THE PREV FCST FLWG THE GFS AND

ALL SOLNS AGREEING ON THE TMG FAIRLY WELL...PLANNING ON STAYING

WITH CONTINUITY  FOR THE REMAINDER OF THE FCST.



SEAS...WL BOOST SEAS SLGTLY IN SHORT TERM WITH THE NE FLOW OVER

NE NT2...AS CRNT DATA INDC THE WAVE GUID IS INIT A LTL LOW.

OTRW...NOT PLANNING ON CHANGING PREV FCST SIGNIFICANTLY.



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

PREVIOUS DISCUSSION...



SUMMARY...12Z NCEP SFC ANALYSIS SHOWS A STATIONARY FRONT EXTNDG E

TO W ACROSS THE SRN NT2 WTRS TO CAPE LOOKOUT...WITH A HI PRES

RIDGE BUILDING S OVER THE NT1 AREA...AND A STRONG LOW CENTERED

ABOUT 330 NM E OF ZONE 905 IN THE NE PART OF THE NT2 WTRS. LATEST

AVAIL ASCAT AND ASCAT HI-RES PASSES FROM THIS MORNING SHOW 20 TO

25 KT WINDS IN NE FLOW OVER ZONE 905...BUT ELSEWHERE IN THE OFSHR

WTRS MAINLY 15 TO 20 KT WINDS. LIGHTNING DENSITY DATA AT 1830Z

SHOWS SCATTERED SHOWERS AND ISOLATED TSTMS IN THE SRN ZONES OF THE

NT2 AREA.



MAIN WEATHER FEATURES...A WEAK LOW NEAR CAPE LOOKOUT WILL MOVE

OFF THE CAROLINA COAST BY THIS EVENING...PASS E OVER THE NT2 WTRS

TONITE INTO THU...THEN MOVE OFF TO THE E LATER THU AND THU NITE. A

COLD FRONT WILL APPROACH THE COAST FRI NITE AND SAT...MOVE

OFFSHORE LATE SAT INTO SAT NITE...SWEEP SE OVER THE OFSHR WTRS

SUN AND SUN NITE...THEN STALL ACROSS THE SRN NT2 WTRS MON AND MON

NITE.



MODELS...THE 12Z MED RNG MDLS ARE IN VRY GUD OVERALL AGREEMNT

ACROSS THE OFSHR WTRS THRU THE FCST PERIOD. GIVEN THAT THE WEATHER

FEATURES INFLUENCING THE OFSHR WTRS THRU MON NITE WILL BE WEAK...THE

12Z GFS 10M SOLN LOOKS REPRESENTATIVE ENUF TO BE USED FOR THE WIND

GRIDS FOR THE ENTIRE FCST PERIOD. 



SEAS...THE 12Z WNA WAVEWATCH III AND 12Z ECMWF WAM BOTH INITIALIZED

WELL OVER THE OFSHR WTRS...AND THE MDLS ARE IN GUD OVERALL AGREEMNT

THRU THE FCST PERIOD WITH ONLY MINOR DIFFERENCES NOTED...SO WILL

USE A 50/50 BLEND OF THE 12Z WNA WAVEWATCH III/ECMWF WAM TO

SMOOTH OUT THE MDL DIFFERENCES.



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



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER KELLS/SCOVIL. OCEAN PREDICTION CENTER.

