

759 

AGPN40 KWNM 310751

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

1251 AM PDT SUN JUL 31 2016



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

.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.



THE LTST GOES WV IMGRY INDC A SOMEWHAT FLAT RDG OVER THE OFSHR

WTRS ATTM...AND AN UPR LOW IN THE GULFAK. THE LTST NCEP SFC ANALYS

INDC A WKNG HIGH PRES RDG ACRS PZ5...AND A PAIR OF LOW PRES TROFS

INTERACTING WITH IT ALONG THE COAST. THE 0420Z RSCAT WINDS INDC

GALES IN THE STG PRES GRAD BTWN CAPE BLANCO AND PT ARENA...AND 30

KT OVR THE NE WAS WTRS NR THE OTHER TROF OVER VANCOUVER ISLE. THE

FCST FM LAST NGT HAD GALES IN THE NE WAS WTRS...AND INDC THEY

WOULD END EARLY THIS MORNING AS THE TROF WEAKENED. CRNT SFC RPRTS

INDC WINDS UP TO 30 KT...AND THE 00Z GFS WINDS ARE INIT OK WHEN

COMPARED WITH THE CRNT DATA. THE GFS INDC 30 KT BY 06Z...WHICH

MATCHES THE CRNT DATA...SO PLANNING ON ENDING THE GALES IN ZONE

PZZ800. HOWEVER...THE DATA STILL INDC GALES ALONG THE NRN CAL 

COAST...AS THE TROF OVER THE CAL INTERIOR IS STILL FAIRLY STG. THE

00Z GFS INDC THE GALES WL CONT THRU TNGT...AND THE 00Z

ECMWF/NAM/UKMET/GEM AGREE FAIRLY WELL ON THE STRENGTH OF THE PRES

GRAD...AND WEAKENING IT BY MON MORNING AS THE HIGH SHIFTS W AND

WEAKENS. THE PREV FCST HAD GALES CONSISTENT WITH THE GFS...THRU

SUN NGT. CONFDC IS STILL HIGH AS THE MDLS AGREE WELL...SO PLANNING

ON KEEPING THE GALE WARNING CLOSE TO THE PREV FCST.



OTRW...THE 00Z MODELS ALL INDC THAT THE AFOREMENTIONED UPPER LOW

IN THE GULFAK WL MOVE SE OVER THE NEXT CPL OF DAYS...AND PASS THRU

THE NRN PZ5 WATERS MON NGT. THE 00Z GFS/ECMWF/UKMET/GEM/NAM STAY

IN GUD AGRMT ON THE SYNOP PTTN THRUT THE RMNDR OF THE FCST

PD...AND ALL INDC A PAIR OF WK CDFNTS WL PASS OVR THE OFSHR WTRS

AND DSIPT TNGT INTO MON NGT. THIS WL ACT TO LOWER STATIC

STABILITY. THE 00Z GFS INDC THAT THE 925 MB WINDS WL INCRS TO 45

KT JUST W OF CAPE MENDOCINO BY LATE WED AS THE WK CD SURGE MOVES

DN THE COAST...AND THE 00Z ECMWF/UKMET INDC ABT THE SAME. THE

VERTICAL SHEAR SHUD INDUCE MIXING...AND WITH THE LOWER

STABILITY.....STGR WINDS ALOFTARE XPCTD TO MIX DN TWD THE SFC. THE

PREV FCST HAD GALES TUE NGT INTO THU. CONFDC IS MDT TO HIGH WITH

THEM...SO PLANNING ON KEEPING PREV WRNG. HOWEVER...ALSO PLANNING

ON EXTENDING THEM INTO THU NGT...AS THE 00Z MDLS INDC THAT THE 925

MB WINDS WL CONT TO BE STG INTO 12Z FRI...SO XPCTG MXG TO MAINTAIN

GALES TO THAT TIME...WITH MDT TO HIGH CONFDC. 



FOR THE FCST...PLANNING ON USING THE 00Z GFS 10M WINDS THRUT THE

FCST...AS THE GFS IS WELL SUPPORTED BY THE REST OF THE 00Z

MODELS...AND HAS BEEN VRY CONSISTENT. HOWEVER...PLANNING ON USING

30M WINDS IN ZONE PZZ820...TO REFLECT THE STGR MIXING XPCTD IN

THAT ZONE.



.SEAS...CRNT SFC RPRTS AND RECENT ALTIMETER PASSES INDC THAT THE

00Z WAVEWATCH-III AND ECMWF WAM MODELS ARE INIT UP TO 3 FT LOW OFF

THE NRN CAL COAST...INVOF THE GALES OFF THE COAST...WHERE SEAS ARE

CRNTLY UP TO 17 FT. OTRW...THE MODELS ARE INIT WELL OVER THE REST

OF THE OFSHR WTRS. THE 00Z MODELS AGREE WELL THRUT THE FCST

PD...SO PLANNING ON FAVORING THE 00Z NWW3 SOLN...AS IT BEST

REFLECTS THE PREFERRED GFS WINDS. HOWEVER...WL BE MAKING MANUAL

EDITS TO THE WAVE HTS OFF THE NRN CAL COAST TO ACCT FOR THE LOW

INITIALIZATION.



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



.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...

     GALE EARLY TODAY INTO TODAY. 



.PZ6 CALIFORNIA WATERS...

.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...

     GALE EARLY TODAY INTO TONIGHT. 

     GALE POSSIBLE TUE NIGHT INTO THU NIGHT. 



$$



.FORECASTER KELLS. OCEAN PREDICTION CENTER.

