

828 

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.

