Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 290104
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
904 PM EDT THU MAY 28 2015

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

PREV GRIDS LOOK EXCELLENT AND ON TRACK COMPARED TO LTST SFC PRELIM
ANALYSIS AND THE FEW OBS ACRS THE AREA. THE DAY SHIFT TRENDED THE
FCST TWDS THE 12Z ECMWF IN THE LATTER PERIODS AS A WK FRONTAL
WAVE FORMS ALONG A STNRY BNDRY ACRS THE NRN NT2 WTRS...THEN SLOWLY
LIFTS ENE ACRS THE OFSHR ZNS. COMBINED WITH A STG SFC HIPRES
BUILDING FROM THE NW THE GRADIENT DRIVEN E-NE-LY WINDS ARE XPCTD
TO REACH 30 KT ON D5 TUE. SHUD BE NOTED THAT THE 18Z GFS TRENDED
SLIGHTLY STGR WITH THIS LOW AND PRES GRAD...AND SUGGESTS AN AREA
OF PSBL GALES OVR ZNS 810 AND 815 IN THE WTRS ADJACENT TO THE NJ
AND LONG ISLAND COASTS.

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

ASCAT METOP-B PASS SHOWING THE BEST CVRG OVER OUTER NT2 AND ERN
NT1 WTRS RETURNED HIGHEST WINDS IN RETURN SSW FLOW AHD OF A WEAK
COD FRONT OVR GLF OF MAINE AND NRN GEORGES BANK...UP TO 20
KT...AND LIGHTER WINDS ASCD WITH PERSISTENT RDG OVR NT2 WTRS.
ANOTHER AREA OF HIGHER WINDS IS NEAR AND E OF BERMUDA IN AREA OF E
TO NE WINDS 20 TO 25 KT AROUND N SIDE OF A LOW S OF AREA. THESE
CONDS ARE IN LIINE WITH ONGOING FCST AND 12Z GFS 10M WNDS. SEA
HEIGHTS ARE QUITE FLAT...ONLY 6 FT OR LESS WITH HIGHER SEAS TO 12
FT ANALYZED ABT 300 NM SE OF BERMUDA. THESE SEAS ARE CLOSE TO 12Z
WNA WW3 EXCP OVER COOLER SST`S OF NT1 AREA WHERE 12Z ECMWF WAM HAS
BEST HNDL ON INITL SEAS.

OVER THE SHORT TERM...THE LATEST MDLS REMAIN IN OVERALL EXCELLENT
AGRMT THAT A WK CDFNT WILL MOVE OFFSHORE NRN WTRS EARLY TONIGHT
AND THEN DSIPT OVR SRN NT1 AREA FRI AS HIGH PRES REMAINS IN PLACE
AS THE HIGH PRES RIDGE REMAINS IN PLACE TO THE S. ASCD MDT
GRADIENTS SPRTG 20 KT OR LESS TONIGHT WIL WKN WITH WK GRADIENTS
PERSISTING INTO FRI NIGHT. THEN 12Z GFS REMAINS CONSISTENT WITH
TIMING AND GRADIENTS ASCD WITH A STRONGER COLD FRONT EXPECTED TO
ONCE AGAIN INCREASE THE RETURN SW FLOW OVER NRN WTRS...UP TO 25 KT
IN GLF OF MAINE SAT INTO SAT NIGHT AS A STG LOW TRACKS E ACRS
CANADA WELL TO THE N WITH PREFNTL GRADIENT DMSHG AS LOW MOVES AWAY
SUN. WITH SPRT FM OTHER 12Z GLOBAL GUIDANCE WILL CONT USING 12Z
GFS 10M WINDS...UP TO 25 KT.

IN THE LONGER RANGE...COLD FRONT MOVS S THRU NT1 AND INTO NRN NT2 WTRS
LATER SUN AND SUN NIGHT AND STALLS OFF DELMARVA MON. UP UNTIL MON
NIGHT 12Z GFS AFTER BEING AGGRESSIVE IN DVLPG A STRONGER LOW ON
THE FRONT OFF MID ATLC CST MON AND MON NIGHT IN ITS PREVIOUS
RUN...TONED DOWN ITS FCST MORE TWD 12Z NON-NCEP MDLS. PRES
GRADIENT BTWN FNT AND HIGH BLDG IN FM N EXPECTED TO PRODUCE NE
WNDS TO 25 KT. THEN LOOKING BYND MON NIGHT SUBTLE DIFFERENCES
NOTED IN MDLS BRING A WEAK H5 SHRTWV ESE FM GRTLKS INTO NT1 WTRS
WITH MORE DIGGING NOTED IN GFS. SINCE GFS HAS BEEN LESS CONSISTENT
THAN OTHER MDLS FOR FCST NEXT WEEK PLAN TO USE THE 12Z ECMWF WHICH
HAS BEEN THE MOST CONSSITENT OF THE MDLS AND HAS SPRT OF 12Z CMC
GLOBAL GEM AND 12Z UKMET. WK LOW DVLPS ON FNT OFF MID ATLC
DELMARVA AREA EARLY TUE AND MOVS ENE PASSING E OF NRN NT2 WTRS
EARLY WED. THIS SOLN IS CLOSE TO WPC DAY 5/6 GUIDANCE. WITH NE
FLOW DVLPG OVR NRN NT2 AREA WHERE CONDS ARE EITHER NEUTRAL OR
SLGTLY UNSTABLE BOOSTED 10M WNDS BY 10 PCT TUE AND TUE NIGHT
PRODUCING WNDS AS HIGH AS 30 KT IN NE NT2 AREA. IT SHOULD BE NOTED
THAT PREVIOUS GFS RUN PRODUCED GALES IN THAT AREA WITH A STRONGER
LOW.

.SEAS...AFTER INITL 12Z ECMWF PREFERENCE...FOR TONIGHT THRU MON NIGHT
USED 12Z WNA WW3 WHICH IS CLOSE TO ECMWF VERSION. THEN AFTER MON
NIGHT TRANSITIONED TO 12Z ECMWF WAM SINCE THAT MDL SFC FCST IS
PREFERRED.

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


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER COLLINS/BANCROFT. OCEAN PREDICTION CENTER.


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