

688 

AGNT40 KWNM 160128

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

928 PM EDT MON AUG 15 2016



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

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



A COLD FRONT IS SHOWING SIGNS OF BCMG NEARLY STATIONARY OVR NRN

NT2 WTRS THIS EVE PER THE LATEST OBS AND SATELLITE IMAGERY. THE

FRONT EXTENDS FROM WEST TO EAST ALONG 39N OR SO...OR EASTWARD

FROM THE SRN JERSEY SHORE. A HIGH PRES RIDGE DOMINATES AREAS TO

THE S FROM SRN NT2 WTRS EASTWARD THROUGH BERMUDA. WEAK HIGH PRES

IS BUILDING E TOWARD NRN NT1 WTRS FROM NEW ENGLAND THIS EVE PER

THE 00Z PRELIM OPC-NCEP SFC ANALYSIS. THE LATEST SATELLITE...

RADAR...AND LIGHTNING DENSITY IMAGERY INDICATES A FEW STRONG

TSTMS NR THE FRONT WELL OFF THE MID ATLC COAST OR NEAR ZONE

ANZ910...WITH ADTL STRONG TSTMS OVR MARYLAND AND VIRGINIA. THE

LATEST SREF TSTM GUIDANCE SUGGESTS THAT THE ACTIVITY WILL

DIMINISH PRIOR TO REACHING THE OFF WTRS OVERNITE. WE WILL KEEP

A CHANCE FOR TSTMS IN THE WTRS OFF THE NRN MID ATLC COAST FOR

TONITE...AND CONT TO MONITOR THE SITUATION. LOCALLY VERY GUSTY

WINDS AND ROUGH SEAS CAN BE EXPECTED IN OR NEAR ANY OF THE

STRONGER TSTMS. OVERALL...WE WILL NOT MAKE MAJOR CHANGES TO THE

PREV OPC FCST FOR THE EVE UPDATE. WE WILL TWEAK WIND GRIDS

SOMEWHAT TO FIT CURRENT CONDITIONS...AND ALSO NEARBY TAFB AND

COASTAL WFO FCSTS A LITTLE BETTER...AND ALTER WEATHER GRIDS TO FIT

CONDITIONS NOTED JUST PRIOR TO FCST ISSUANCE.



SEAS...SEAS HEIGHTS APPEAR TO BE RUNNING VERY CLOSE TO THE PREV

FCST PER THE LATEST OBS...ALTIMETER DATA...AND RA1 SEA STATE

ANALYSIS. FOR THE EVE UPDATE WE WILL ONLY TWEAK THE PREV GRIDS

SLIGHTLY TO FIT NEARBY WFO AND TAFB FCSTS A LITTLE BETTER. OVERALL

NO SIGNIFICANT CHANGES APPEAR NEEDED TO THE ONGOING FCST THIS

EVE.



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

PREVIOUS DISCUSSION...



THE MOST RECENT ASCAT PASS SHOWS MAINLY LIGHT WINDS ACROSS THE

OFFSHORE WATERS...LESS THAN 15 KT. THE RIDGE AXIS EXTENDS E/W

ALONG 33N OVER THE WATERS. SEAS ARE GENERALLY 2-4 FT ACROSS THE

ENTIRE AREA. THE PROGRESSIVE UPR LEVEL PATTERN WILL CONTINUE OVER

THE NRN WATERS DURING THE NEXT 3 DAYS AS THE RIDGE AXIS PERSISTS

ACROSS THE SRN REGION. ON DAYS 3-5 A S/WV WILL MOVE E OVER THE

WATERS WHILE WEAKENING THE UPR RIDGE. DAYS 5 AND 6 WILL BRING A

BUILDING RIDGE TO THE NRN AND CENTRAL WATERS.



THE 12Z GLOBAL MODELS ARE IN VERY GOOD AGREEMENT THROUGH 00Z

THU...THEN BEGIN TO DIVERGE SLIGHTLY...MAINLY DUE THE THE

POSITION OF A FRONTAL BNDRY AND ASSOCIATE WAVE THAT MOVES OFF THE

CST. THE UKMET AND THE GFS ARE IN THE BEST AGREEMENT THROUGH 18Z

FRI...THEREFOR WILL POP THE WIND GRIDS USING THE 10M GFS THROUGH

THEN. AFTER 18Z FRI...THE ECMWF AND UKMET ARE MORE SIMILAR...WHILE

THE GFS IS THE OUTLIER. WILL POP THE WIND GIRDS USING THE ECMWF

FROM 21Z FRI THROUGH THE REMAINDER OF THE 7 DAY PERIOD.



SEAS...THE WW3 AND WAM WERE BOTH INITALIZED WELL. WILL POP THE

WAVE GRIDS USING THE CORRESPONDING WIND GRIDS TO MATCH.



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





.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER MILLS/SHAW. OCEAN PREDICTION CENTER.

