

542 

AGNT40 KWNM 210221

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

1021 PM EDT SAT AUG 20 2016



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

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



ANTICIPATE MAKING VERY LITTLE CHANGES TO THE ONGOING FORECAST THAT

IS ALREADY IN PLACE. WITH GREAT AGREEMENT AMONG 12Z DETERMINISTIC

SOLNS...WHICH ARE IN CONCERT WITH 12Z GEFS AND EPS MEANS...12Z GFS

REMAINS PREFERRED BASIS FOR GRIDS AND TEXT FORECASTS. 



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

PREVIOUS DISCUSSION...



THE 12Z SFC ANALYSIS INDICATED WEAK LOW PRES JUST OFF THE N

CAROLINA COAST WITH STATIONARY FRONT EXTENDING E. WEAK COLD FRONT

EXTENDED ACROSS THE FAR NE NT2 AND SRN NT1 WATERS. SATELLITE

IMAGERY AND LIGHTNING DATA INDICATE THAT AREA OF TSTMS OVER FAR

SRN NT2 WATERS HAS DECREASED IN COVERAGE AND INTENSITY. SCT TSTSMS

WERE ALSO NOTED NEAR AND JUST N OF GULF STREAM JUST S OF COLD

FRONT. ASCAT PASS MISSED MOST OF OFFSHORE WATERS...BUT DECENT

COVERAGE OVER COASTAL WATERS. OVERALL...THE RETURNS WERE CLOSE TO

THE MODEL GUIDANCE.



THE 12Z MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT DURING THE

FCST PERIOD...AND WILL CONTINUE TO USE THE GFS 10M WINDS TO

POPULATE WIND GRIDS. ALL OF THE MODELS ARE VERY SIMILAR WITH THE

LOW OFF N CAROLINA COAST TRACKING E TONIGHT INTO EARLY SUN

MORNING...THEN TURNING N SUN AND SUN NIGHT PULLING FRONT N AS A

WARM FRONT BEFORE MERGING WITH ANOTHER LOW PASSING N OF GULF OF

MAINE LATE SUN NIGHT AND MON. A COLD FRONT WILL MOVE OFFSHORE SUN

NIGHT...THEN CONTINUE SE ACROSS THE OFFSHORE WATERS THROUGH MON

BEFORE STALLING JUST E OF THE AREA MON NIGHT. THE MODELS ARE ALSO

ALL ON DECENT AGREEMENT WITH THE TIMING AND INTENSITY OF THIS

FRONT. WILL CONTINUE TO CAP WINDS AT 20 KT AHEAD OF THE COLD FRONT

SUN NIGHT...WITH POST FRONTAL WINDS TO 25 KT LATE SUN NIGHT MAINLY

OVER WRN PORTIONS. HIGH PRES WILL BUILD ACROSS THE AREA AND

DOMINATE FOR THE REMAINDER OF THE PERIOD. 



.SEAS...THE 18Z SEA STATE ANALYSIS INDICATED THAT OBSERVED SEAS

MATCHED UP WELL WITH BOTH THE MWW3 AND ECMWF WAM. SINCE WILL BE

USING THE GFS FOR WINDS...WILL ALSO POPULATE WAVE GRIDS USING THE

MWW3 THROUGH THE PERIOD...THOUGH THE ECMWF WAM IS VERY CLOSE. 



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





.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER COLLINS/KOSIER. OCEAN PREDICTION CENTER.

