

624 

AGNT40 KWNM 061915

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

315 PM EDT SAT AUG 6 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 WARM FRONT ARCING ROUGHLY

E TO W ACROSS THE CENTRAL AND SRN NT2 WTRS...WITH A COLD FRONT

APPROACHING THE NEW ENGLAND STATES. LATEST AVAILABLE ASCAT AND

ASCAT HI-RES PASSES FROM THIS MORNING SHOW WINDS OF 20 TO 25 KT IN

SW FLOW OVER THE CENTRAL AND SRN NT2 WTRS AND WINDS TO 20 KT IN SW

FLOW IN THE GULF OF MAINE...BUT OTHERWISE INDICATE WINDS OF 15 KT

OR LESS OVER THE OFSHR WTRS. LIGHTNING DENSITY PRODUCT DATA AT

1840Z SHOW SCATTERED SHOWERS AND TSTMS OVER THE CENTRAL AND SRN

NT2 WTRS.



MAIN WEATHER FEATURES...A COLD FRONT WILL MOVE OFFSHORE THIS EVNG

AND TONITE...CONTINUE SE OVER THE OFSHR WTRS SUN AND SUN

NITE...THEN STALL AND WEAKEN ACROSS THE SRN NT2 WTRS MON INTO TUE.

ANOTHER COLD FRONT WILL APPROACH THE COAST FROM THE NW LATE WED

AND WED NITE...THEN MOVE OFFSHORE THU AND THU NITE. A WEAK LOW

COULD MOVE N THEN NW OVER THE SRN NT2 WTRS WED THRU THU.



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

FOR TONITE THRU TUE...SO THE REPRESENTATIVE 12Z GFS 10M SOLN WILL

BE USED FOR THE WIND GRIDS OVER THIS TIMEFRAME. DURING THE TUE

NITE THRU THU NITE PERIOD THE 12Z ECMWF/UKMET LIFT A LOW N INTO

THE NT2 WTRS...ALTHO THE 12Z UKMET BECOMES MUCH STRONGER WITH THE

LOW BY THU NITE. HOWEVER THE 12Z GEM/GFS DO NOT CARRY THE LOW

COMING UP FROM THE S FOR TUE NITE THRU THU NITE...SO FOR NOW WILL

NOT BE MENTIONING THIS LOW IN THE OFSHR WTRS FCST BECAUSE IT IS

NEAR THE END OF THE FCST PERIOD AND THE OVERALL MDL AGREEMNT IS

POOR ATTM. WILL USE THE 12Z ECMWF FOR TUE NITE THRU THU NITE SINCE

IT APPEARS TO BE THE BEST MEDIAN MDL SOLN ATTM.



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

INITIALIZED WELL OVER THE OFSHR WTRS. THE MDLS ARE IN VRY GUD

AGREEMNT FOR TONITE THRU TUE...SO WILL JUST USE THE 12Z WNA

WAVEWATCH III MDL FOR THIS TIMEFRAME. WILL BE USING A 25/75 BLEND

OF THE 12Z WNA WAVEWATCH III/ECMWF WAM FOR TUE NITE THRU THU

NITE...DUE TO THE POSSIBILITY THAT THE GFS DRIVEN 12Z WNA

WAVEWATCH III IS UNDER FCSTG THE WAVE HTS IN THE SRN NT2 WTRS FOR

THAT PERIOD.



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



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER SCOVIL. OCEAN PREDICTION CENTER.

