

098 

AGNT40 KWNM 200702

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

302 AM EDT SAT AUG 20 2016



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

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



THE LTST GOES IR IMGRY INDC A FRONTAL BNDRY OVR C NT2...AND THE

LGTNG DENSITY PROD INDC SHOWERS AND TSTMS JUST AHD OF THE FRONT.

THE PREV FCST HAD MENTION OF SHOWERS AND TSTMS IN THE LAST

FCST...SO ATTM PLANNING ON MAINTAINING IT IN THE NEXT PKG. THE

00Z GFS/NAM AND 12Z ECMWF/UKMET/GEM ALL AGREE WITH KEEPING A WK

FRNTL BNDRY IN C NT2 INTO TNGT...WHICH SHUD ACT AS A FOCUS FOR

CONVECTION IN THE MARINGALLY UNSTABLE ENVIRONMENT OVER THE GULF

STREAM. THE 03Z SREF MDL INDC CONVECTIVE ACTIVITY IS LIKELY ALONG

THE FRONT...SO PLANNING ON KEEPING SHOWERS AND TSTMS THRU AT

LEAST THE COUPLE OF PERIODS IN NT2. IN ADDITION...THE ASCAT WINDS

FM 01Z AND 02Z INDC UP TO 15 KT AHEAD OF THE FRONT. HOWEVER...CRNT

SFC RPRTS INDC UP TO 15 KT WITH A FEW SMALL AREAS NEAR 20 KT. THE

PREV FCST STARTED OUT WITH 15 KT...SO WL BOOST TO 20 KT FOR TDA. 

THE 00Z MDLS ALL INDC THAT THE FRONT WL LIFT N THRU NT2 SUN INTO

SUN NGT...AND AGREE WELL ON THE TMG AND INTNSTY. THE PREV FCST

FAVORED THE GFS FOR THIS FEATURE...AND WITH THE GFS REMAINING

CONSISTENT...PLANNING ON CONTG ALONG THOSE LINES IN THE NEXT PKG.



OTRW...THE 00Z MDLS ALL INDC ANOTHER FRONT WL MOV INTO THE W ATLC

SUN NGT INTO MON. EARLIER RUNS OF THE ECWMF HAD WINDS UP TO 25 KT

IN THE S FLOW OVR NT1 AHD OF THE FRONT...AND THE GFS HAD BEEN

CONSISTENT WITH 20 KT. THE 00Z ECWMF HAS TRENDED WKR...AND NOW HAS

ONLY ABT 15 KT OVR THE GULF OF MAINE. THE 00Z MDLS ALL AGREE VRY

WELL NOW ON THE TMG OF THE FRONT...AND ARE IN DECENT AGRMT ON THE

INTNSTY ON THE S FLOW. AS A RESULT...PLANNING ON GOING UP TO 15 KT

WITH A SMALL AREA OF 20 KT. THE 00Z MDLS ALSO AGREE ON THE

INTNSTY OF THE WINDS IN THE CAA....WITH MAINLY 25 KT MAX. THE

PREV FCST STAYED NR THE GFS FOR THE WINDS IN THE CAA...AND WITH

THE REST OF THE 00Z MDLS AGREEING WITH THE GFS...WL CONT WITH IT

FOR THIS FEATURE. THE 00Z MDLS ALSO RMN IN GUD AGRMT IN THE

EXTENDED...AS THE AFOREMENTIONED FRONT STALLS E AND SE OF THE NT2

WATERS...WHILE HIGH PRES BUILDS OVER THE W ATLC. WITH NO MAJOR

DIFFS THRUT THE RMNDR OF THE FCST PD...WL CONT WITH THE 00Z THRUT

THE PD.



SEAS...THE 00Z WNA WAVEWATCH III MDL AND 12Z ECMWF WAM BOTH

INITIALIZED WELL OVER THE OFSHR WTRS...WITH SEAS GENLY 5 FT OR

LESS. THE MDLS ARE IN GUD AGREEMNT THRU THE FCST PERIOD WITH ONLY

RELATIVELY MINOR DIFFS...SO WILL USE A 50/50 BLEND OF THE 2 SOLNS

TO SMOOTH OUT THE DIFFS.



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



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER KELLS. OCEAN PREDICTION CENTER.

