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000
AGNT40 KWNM 200058
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
900 PM EDT WED 19 JUN 2013

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.

COLD FRONT SHUD STALL OFF SC COAST OVER NEXT FEW HRS AND PERSIST
OVER NEXT FEW DAYS. PAST COUPLE RUNS OF GFS HAVE COME MORE IN
LINE WITH ECMWF/UKMET IN BEING WEAKER WITH ANY SFC LOW DVLPMNT
ALNG FRONT THU NGT/FRI. AT THAT TIME FRONT SHUD BEGIN TO DRIFT N
AS WEAK WARM FRONT. 12Z/18Z GFS LOOK REASONABLE AND ARE WELL
SUPPORTED BY 12Z ECMWF/UKMET THRU FRI NGT. BY SAT GFS APPEARS
TOO STRONG WITH COLD FRONT MOVG OFFSHORE NEW ENGL ALONG WITH
ASSOC SW WINDS OVER NT1 WATERS. PREFERRING A 50/50 BLEND WITH
ECMWF TO LOWER THESE WINDS SAT AND AGAIN WITH TROF/WEAK FRONT
APPROACHING MON. 18Z MULTIGRID WAVEWATCH III IS IN GOOD
AGREEMENT WITH W ATLC SHIP/BUOY OBS THIS EVENING...AND LOOKS
REASONABLE THRU FRI NGT. THEN PREFER 12Z ECMWF WV MDL AND ITS
LOWER SIG WV HGTS OVER NEW ENGL WATERS SAT THRU MON.

----------------------------------------------------------------
...PREVIOUS DISCUSSION...

SUMMARY...A LOW IS CNTRD ABOUT 130 NM E OF THE GEORGES BANK AREA
THIS AFTN WITH AN ASCD COLD FNT EXTNDG SW ACROSS THE NRN/CNTRL
NT2 WTRS. THE LOW WILL MOVE OFF TO THE NE TONITE...PULLING THE
COLD FNT INTO THE CNTRL/SRN NT2 WTRS. RDG WILL BLD OVER THE NT1
WTRS TONITE...THEN MOVE E ACROSS THE NT1 AREA THU INTO SUN WHILE
GRADU WKNG. THE FNT WILL STALL ACROSS THE CNTRL/SRN WTRS THU
THRU SUN. ANOTHER LOW IS EXPCTD TO FORM ALG THE FNT OVER THE SRN
NT2 WTRS THU...DRIFT NE ALG THE FNT THU NITE AND FRI...THEN
DSIPT FRI NITE. RDG WILL BLD OVER THE NT2 WTRS SAT AND SUN. A
WEAK COLD FNT WILL APRCH THE NT1 AREA SAT INTO SUN...THEN DSIPT
LATE SUN. A WEAK TROF WILL MOVE E INTO THE NT1 AREA MON...AS RDG
PERSISTS OVER THE NT2 WTRS.

MODELS...NAM AND THE MED RNG MDLS ARE IN GUD OVERALL AGREEMNT
INTO EARLY FRI...AND WILL BE FAVORING THE GFS THRU THIS
TIMEFRAME...MAINLY BECAUSE IT APRS TO HV THE BEST HANDLE ON THE
WINDS AHD/BHD THE COLD FNT FOR THIS AFTN INTO TONITE. THE GFS
HANGS ONTO THE FNTL LOW LONGER THAN MOST OF THE OTHER MED RNG
MDLS...AND IS STGR THAN MOST OF THE MDLS WITH THE SW FLOW OVER
THE NT1 WTRS FOR THE SAT INTO EARLY SUN PRD...SO WILL BE
FAVORING A BLEND OF THE ECMWF/GFS FOR LATER FRI THRU MON
TIMEFRAME TO SMOOTH OUT THESE DIFFS.

SEAS...MULTIGRID WW3 INITIALIZED BEST OVER THE CSTL/OFSHR
WTRS...AND WILL BE USED INTO EARLY FRI. WILL BE USING A BLEND OF
THE MULTIGRID WW3 AND ECWMF WAM FOR LATER FRI THRU MON...DUE TO
REASONS NOTED ABV IN THE MODELS SECTION.

EXTRATROPICAL STORM SURGE GUIDANCE...N/A.

.WARNINGS/FORECAST CONFIDENCE...PRELIMINARY. ANY CHANGES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.NT1 NEW ENGLAND WATERS...
.GULF OF MAINE...NONE.
.GEORGES BANK...NONE.
.SOUTH OF NEW ENGLAND...NONE.

.NT2 MID ATLC WATERS...
.HUDSON CANYON TO BALTIMORE CANYON...NONE.
.BALTIMORE CANYON TO HAGUE LINE...NONE.
.BALTIMORE CANYON TO HATTERAS CANYON...NONE.
.HATTERAS CANYON TO CAPE FEAR...NONE.
.CAPE FEAR TO 31N...NONE.
$$

.FORECASTER CLARK/SCOVIL. OCEAN PREDICTION CENTER.