

749 

AGNT40 KWNM 131910

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

310 PM EDT SAT AUG 13 2016



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

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



SUMMARY...12Z NCEP SFC ANALYSIS SHOWS A WEAK COLD FRONT EXTNDG E

TO W ACROSS THE GEORGES BANK ZONES OF THE NT1 WTRS. OTHERWISE THE

ANALYIS INDICATES HI PRES RIDGING OVER THE NT2 WTRS...WITH

ANOTHER RIDGE BUILDING SE INTO THE GULF OF MAINE. LATEST AVAILABLE

ASCAT HI-RES AND ASCAT PASSES FROM THIS MORNING SHOW WINDS TO 20

KT OVER MOST OF THE NT1 AND NRN NT2 WTRS...BUT OTHERWISE INDICATE 

LIGHT WINDS OF 15 KT OR LESS ACROSS THE OFSHR WTRS. LIGHTNING

DENSITY PRODUCT DATA AT 1850Z SHOWS SCATTERED SHOWERS OVER ZONE

920 OF THE NRN NT2 WTRS. 



MAIN WEATHER FEATURES...THE WEAK COLD FRONT OVER THE NT1 AREA WILL

BECOME STATIONARY ACROSS THE GULF OF MAINE THIS EVENING...THEN

LIFT NE AS A WARM FRONT TONITE INTO SUN AS IT PASSES N OF THE NT1

AREA. A WEAK LOW WILL MOVE SE TONITE AND SUN...PASSING JUST N OF

THE NT1 WTRS SUN EVENING...THEN ACCELERATE OFF TO THE E SUN NITE

AND MON. THE LOW WILL PULL A COLD FRONT SE OVER THE NT1 AND NRN

NT2 WTRS SUN NITE AND MON. ANOTHER RIDGE WILL BUILD OVER THE NT1

WTRS LATE MON AND MON NITE...THEN MOVE E ACROSS THE NT1 AREA TUE

INTO TUE NITE. ANOTHER LOW WILL PASS E OVER THE NRN NT1 WTRS LATE

WED INTO WED NITE...THEN ACCELERATE OFF TO THE E THU. A LOW PRES

TROF WILL APPROACH THE COAST THU...THEN MOVE OFFSHR INTO THE NT1

AND NRN NT2 WTRS THU NITE.



MODELS...THE 12Z MED RNG MDLS ARE IN VERY GOOD AGREEMNT ACROSS

THE OFSHR WTRS THRU TUE NITE. THE CONSENSUS OF THE MDLS CONTINUES 

TO SHOW THAT A LOW WILL PASS E OVER THE NT1 AREA LATER WED AND

WED NITE...BUT WITH THE EXCEPTION OF 12Z ECMWF/UKMET THE MED RNG

MDLS ARE STILL NOT IN GOOD AGREEMNT REGARDING THE STRENGTH AND

TIMING OF THIS LOW. ECMWF WILL BE USED TO POPULATE THE WIND GRIDS

FOR THE ENTIRE FCST PERIOD...MAINLY BECAUSE IT LOOKS LIKE THE BEST

MEDIAN MDL SOLN AND HAS SHOWN VERY GOOD RUN TO RUN CONSISTENCY.



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

INITIALIZED WELL OVER THE OFSHR/COASTAL WTRS VERSUS THE 12Z RA1

SEA STATE ANALYSIS. THE WNA WAVEWATCH III AND ECMWF WAM ARE IN

VERY GOOD AGREEMNT ACROSS THE OFSHR WTRS THRU THE FCST

PERIOD...EXCEPT THE WNA WAVEWATCH LOOKS NOTICEABLY UNDERDONE FOR

TUE NITE INTO THU OVER THE NT1 AND NRN NT2 WTRS. IN ORDER TO BE

CONSISTENT WITH THE PREFERRED 12Z ECMWF...THE 12Z ECMWF WAM WILL

BE USED FOR THE WAVE HT GRIDS FOR THE ENTIRE FCST PERIOD.



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



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER SCOVIL. OCEAN PREDICTION CENTER.

