Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 271318
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
920 AM EDT WED 27 JUL 2016

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

MULTIPLE SUPERCELLS EXTENDED ALONG A LINE ACROSS THE CENTRAL NT2
WATERS FROM NEAR 35N68W TO 35N71W TO 36N74W INVOF OR JUST S OF A
STATIONARY FRONT THIS MORNING. WRN MOST CELLS SHOULD PASS E OF
THE INNER ANZ828 WATERS WITHIN THE HALF HOUR BUT WILL CONTINUE
TO MENTION HIGHER WINDS IN TSTMS ACROSS ANZ925. THIS QUASI
STATIONARY BOUNDARY SHOULD REMAIN A FOCUS FOR STRONG TO POSSIBLY
SEVERE TSTMS TODAY THROUGH THU NIGHT. AT THE END OF THE WEEK AND
OVER THE WEEKEND MODELS HAVE NOT SHOWN RUN TO RUN CONSISTENCY
AND ARE HAVING DIFFICULTY WITH THE TIMING OF MULTIPLE DEVELOPING
MOSTLY RELATIVELY WEAK SURFACE LOWS TO MOVE E ACROSS THE NRN NT1
AND SRN NT2 WATERS ALONG THE FRONT. LATEST GUIDANCE DID NOT
OFFER ANY REASON TO MAKE SIGNIFICANT CHANGES PREVIOUS OPC WIND
GRIDS... WHICH ARE SLIGHLY STRONGER WITH SW WINDS ACROSS THE NRN
NT2 WATERS FRI NIGHT/SAT. THE 00Z/06Z WAVEWATCH III AND 00Z
ECMWF WAM ARE REASONABLY WELL INITIALIZED WITH WAVE HEIGHTS
ACROSS THE W ATLC THIS MORNING.

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

THE 00Z GLOBAL MODELS APPEAR TO HAVE INITIALIZED WELL EARLY THIS
MORNING BASED ON THE LATEST OBS AND EVE ASCAT PASSES WITH MAX
WINDS NR 20 KT OCCURRING OVR NE NT2 WTRS AND FAR SW NT2 WTRS.
LOCALLY HIGHER WINDS NR GALE FORCE WERE NOTED ON THESE ASCAT
PASSES LKLY IN OR NR TSTMS OVR FAR NE NT2 WTRS OR OFF ZONES
ANZ910 AND 910 LATE LAST EVE.

THE LATEST SATELLITE AND LIGHTNING DENSITY DATA INDICATE A
STRONG TSTM E OF VIRGINIA BEACH (OFFSHORE ZONE ANZ828) WITH SCTD
TSTMS EXTENDING FROM THIS REGION E AND NE OVR THE CENTRAL NT2
WTRS. THE LATEST SREF TSTMS GUIDANCE KEEPS THE THREAT FOR THE
STRONGEST TSTMS OVR MAINLY CENTRAL INTO THE NRN PORTIONS OF NT2
WTRS TODAY INTO THU. LOCALLY STRONG WINDS EXCEEDING GALE FORCE
ARE POSSIBLE IN OR NR THE STRONGER TSTMS.

OTW...A WEAK COLD FRONT EXTENDS FROM NR 40N62W W-SW OVR NRN NT2
WTRS AND REACHES THE COAST NR THE JERSEY SHORE EARLY THIS
MORNING PER THE 06Z PRELIM OPC-NCEP SFC ANALYSIS. THE FRONT IS
STILL EXPECTED TO BECOME STNRY LTR TODAY AND TONITE OVR NRN OR
CENTRAL NT2. ANOTHER WEAK COLD FRONT WILL APPROACH FROM THE NW
TONITE INTO THU...AND NEAR THE COAST THU NITE INTO EARLY FRI.
FOR THE EARLY AM PACKAGE WE WILL STAY CLOSE TO THE 00Z GFS 10M
WINDS FOR TODAY INTO THU EVE...AND THEN TRANSITION TO THE PREV
GRIDS FOR FRI AS THE 00Z ECMWF IS VERY SIMILAR TO THE 12Z ECMWF
CYCLE THAT WAS PREFERRED IN THE PREV FCST. THE 00Z GFS IS
TRENDING TOWARD THE ECMWF SOLUTION BY FRI...WITH WEAK LOW PRES
MOVG E ALONG THE COLD FRONT LATER FRI...ALTHO IT MAY STILL BE A
TAD TOO FAST. FOR THE REMAINDER OF THE PACKAGE FRI NITE THRU SUN
NITE WE WILL RELY ON THE PREV SET OF GRIDS AS THE 00Z ECMWF IS
VRY SIMILAR TO THE 12Z CYCLE WHICH WAS USED FOR THE PREV
FCST...AND WE SEE NO NEED TO MAKE SIG CHANGES FOR THE LONGER
TERM PORTION OF THE FCST AT THIS TIME. THE LOW WILL TRACK E FROM
NR CAPE MAY LTR FRI AND FRI NITE...AND PASS OVR FAR SRN NT1 WTRS
SAT INTO SAT NITE WHILE PULLING THE ASSOC COLD FRONT
SOUTHEASTWARD OVR THE REGION. THE FRONT STILL APPEARS AS IF IT
WILL STALL OVR NRN NT2 WTRS SAT NITE WITH A SERIES OF LOWS
TRACKING E ALONG THE FRONT SUN AND SUN NITE.

SEAS...BOTH THE 00Z WNA WAVEWATCH III AND 00Z ECMWF WAM MDLS
INITIALIZED FAIRLY WELL OVR THE OFF WTRS PER THE LATEST OBS. SEA
HEIGHTS RANGE FROM 1 TO 3 FT OVR THE GULF OF MAINE WTRS TO 3 TO
5 FT FROM SRN NT1 WTRS S OVR MOST OF THE NT2 WTRS PER THE LATEST
OBS AND ALTIMETER DATA. FOR THE EARLY AM PACKAGE AND TO REMAIN
CONSISTENT WITH THE WIND FCST WE WILL RELY ON THE 00Z WNA WV
WATCH III MDL GUID FOR TODAY INTO THU NITE...AND THEN TRANSITION
TO THE PREV GRIDS AND FCST FOR LTR THU NITE AND FRI THRU THE
UPCOMING WKND.

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

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER CLARK/MILLS. OCEAN PREDICTION CENTER.



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