

771 

AGNT40 KWNM 120144

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN 

NWS OCEAN PREDICTION CENTER WASHINGTON DC

945 PM EDT THU 11 AUG 2016 



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

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



A 1930Z/11 RAPIDSCAT OVERPASS INDICATED WINDS TO 25 KT SE OF 

GEORGES BANK AND ALSO SW 20 KT ACROSS SRN NT1 AND NRN NT2 

WATERS. THE 18Z GFS AND 12Z ECMWF ARE WELL INITIALIZED WITH 

OFFSHORE WINDS THIS EVENING. LATEST GUIDANCE AND OBS DO NOT 

OFFER ANY REASONS TO MAKE ANY SIGNIFICANT CHANGES TO PREVIOUS 

GRIDS. 18Z WAVEWATCH III IS ALSO WELL INTIALIZED WITH W ATLC 

WAVE HEIGHTS THIS EVENING.



----------------------------------------------------------------

...PREVIOUS DISCUSSION...



SUMMARY...12Z NCEP SFC ANALYSIS SHOWS A WEAK HIGH PRES RIDGE 

OVER THE OFSHR AND COASTAL WTRS...WITH A WEAK TROF OVER THE GULF 

OF MAINE AND A WEAK COLD FRONT APPROACHING NRN NEW ENGLAND FROM 

THE NW. LATEST AVAILABLE ASCAT HI-RES AND ASCAT PASSES FROM LAST 

NITE INDICATE LIGHT WINDS OF 15 KT OR LESS OVER THE OFSHR 

WTRS...SO THE 12Z ECMWF MDL APRS TO BE INITIALIZING QUITE WELL 

THERE. LIGHTNING DENSITY PRODUCT DATA AT 1850Z DOES NOT SHOW ANY 

SHOWER OR TSTM ACTIVITY OVER THE OFSHR WTRS. 



MAIN WEATHER FEATURES...A WEAK SUMMERTIME PATTERN WILL PREVAIL 

ACROSS THE OFSHR WTRS THRU THE FCST PERIOD...WITH WINDS NOT 

EXPECTED TO EXCEED 20 KT. THE WEAK COLD FRONT WILL APPROACH THE 

NEW ENGLAND STATES FROM THE NW TONITE...THEN BECOME STATIONARY 

ACROSS THE GULF OF MAINE FRI THRU MON. A SERIES OF WEAK LOWS 

WILL PASS E ALONG THE FRONT ACROSS THE GULF OF MAINE FRI NITE 

THRU SUN NITE. A HI PRES RIDGE WILL BUILD OVER THE NT1 AREA 

MON...THEN MOVE E OVER THE WTRS MON NITE THRU TUE NITE. 



MODELS...THE 12Z MED RNG MDLS ARE IN GUD OVERALL AGREEMNT THRU 

TUE NITE...EXCEPT THE 12Z UKMET BRINGS A VERY STRONG LOW INTO 

THE GREAT LAKES REGION ON TUE NITE WHICH LOOKS VERY ANONALOUS. 

THE 12Z ECMWF APPEARS TO FIT IN BEST WITH THE WEAK SUMMERTIME 

PATTERN EXPECTED THRU TUE NITE...SO IT WILL BE USED TO POPULATE 

THE WIND GRIDS FOR THE ENTIRE FCST PERIOD. 



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

INITIALIZED WELL OVER THE OFFSHORE/COASTAL WTRS...AND ARE IN 

REASONABLY GUD AGREEMNT THRU THE FCST PRD. SINCE THE 12Z ECWMF 

IS THE PREFERRED MDL SOLN FOR THE ENTIRE FCST PERIOD...IN ORDER 

TO BE CONSISTENT WILL USE THE 12Z ECMWF WAM ALL THE WAY THRU THE 

FCST PERIOD. 



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



.WARNINGS...PRELIMINARY. 



.NT1 NEW ENGLAND WATERS... 

     NONE. 



.NT2 MID ATLC WATERS... 

     NONE. 



$$ 



.FORECASTER CLARK/SCOVIL. OCEAN PREDICTION CENTER.

