Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 262200
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
300 PM PDT THU MAR 26 2015

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.

A SLOW MOVG AND WKNG CDFNT IS APCHG PZ5 AND NRN CA WTRS FM W AS
OF 18Z NCEP SFC ANAL WHILE A WK HIGH PRES RDG EXTENDS ACRS SE
OREGON AND NRN AND CENTRAL CA WTRS TO A HIGH CNTR 34N130W. ASCAT-A
AND B PASSES FM ARND 18Z AND REGULAR SFC OBS SHOW MOSTLY LIGHT
WINDS EXCP OUTER PZ5 WTRS NR FNT WHERE S WINDS ARE UP TO 20 KT.
THESE WNDS ARE CLOSE TO 12Z GFS 10M WNDS.

SYNOPSIS...APCHG NEUTRALLY TILTED H5 UPR TROF IS FCST BY 12Z MDLS
TO TRIGGER A WAVE ON THE AFOREMENTIONED WK CDFNT W OF OREGON WTRS
EARLY TONIGHT AND MOV IT NE PAST NW WA WTRS EARLY FRI. WITH UPR
SHRTWV MOVG THRU A L/W RDG PSN NR W CST LOW PRES AND FNT ARE FCST
TO REMAIN WK WITH WNDS LKLY NOT EXCEEDING 20 KT WITH FNT AND ALSO
WITH BLDG RDG FM W BHND FNT ON FRI. FNT LOSING DEFINITION AS IT
APCHS CST LATE FRI. RDG REBLDG OVR WTRS LATER FRI INTO SAT AHD OF
A STRONGER APCHG FNT...WITH THE RDG AND HIGH PRES TO SW PRESSING
AGAINST INLAND TROF OVR CA. MDLS HAVE BEEN CONSISTENT SHOWING FOR
OFSHR WTRS WNDS MAXIMIZING AT 30 KT PT PIEDRAS BLANCAS TO NR CAPE
MENDOCINO IN INNER WTRS WITH GALES ALSO PSBL BUT FOR NOW LEAVE
BEST CHC FOR ADJ CSTL WTRS PT REYES TO PT ARENA AREA. THE MDLS
SHOW THE SECOND FNT SLOWING DOWN AS IT APCHS NW WTRS LATE SAT AND
HAS GALES AHD OF IT EVEN IN MDL 10M WNDS BUT WITH PARENT LOW PRES
MOVG N INTO GLF OF AK AND FNT LOSING SPRT AS UPR FLOW GOES SW MDL
AGRMT SPRTS ONLY MAX WNDS 30 KT FOR NW PZ5 WTRS SAT INTO SAT NIGHT
BEFORE FNT WKNS. BY SUN MRNG 12Z MDLS ARE IN AGRMT FRMG A WAVE ON
FNT WELL W OF CA OFSHR WTRS WITH A MORE POTENT NEG TILT H5 S/W
TROF PROVIDING SPRT AS IT MOVS NE ALG STALLED FNT. DISCOUNTING
MORE AMPLIFIED 12Z GLOBAL GEM...PREFER 12Z GFS FOR SUN INTO MON
FOR FCST OF DVLPG LOW TRACKING NW AND PASSING JUST NW OF WTRS
EARLY MON BUT TIME SHIFTED 3 HR FASTER AND TWD A BIT FASTER AND
DEEPER 12Z UKMET/ECMWF SOLNS...WITH WNDS BOOSTED BY 5 PCT. WILL
CARRY MRGL GALES WITH LOW TO MOD CONFDC BUT FOR MAINLY OUTER
PORTIONS OF PZ5 N OF CAPE LOOKOUT. AS LOW AND ASCD SHRTWV IMPACT
WTRS SFC RDG TO E AND SE IS SUPPRESSED S AND THE MDT TO STG WNDS
OFF CA SHOULD WKN TEMPORARILY TO 25 KT OR LESS ON MON.

EXTENDED...MON NIGHT THRU TUE NIGHT...AS AFOREMENTIONED STRONG LOW
LIFTS RPDLY N AWAY FM AREA BROAD RIDGING BLDS BACK INTO WTRS. 12Z
GFS BRINGS GALES INTO PZ5 WTRS WITH A LOW TRACKING FM W ON
TUE...BUT OTHER 12Z GUIDANCE AND 12Z GEFS/00Z ECMWF ENSEMBLE
GUIDANCE SUGGEST LOW TRACKING FARTHER N OR NW...AS ALSO PREFERRED
BY WPC DAY 5 GUIDANCE. PREFER WEAKER 12Z ECMWF SOLN TRAKING LOW
FARTHER N MAINLY AS A TROF...WITH UPR SPRT AMONG MDLS APPEARING
FRAGMENTED. WNDS MAXING OUT AT 30 KT NRN WTRS WITH PASSING LOW
AND FNT TUE. RDG BLDG AHD OF LOW AND EVEN MORE STRONGLY AS LOW
PASSES TUE NIGHT...RESULTING IN REBLDG OF GRADIENT OFF CA AND WNDS
APCHG GALE FORCE OFF CENTRAL CA TUE NIGHT. CARRYING GALES IN
GRIDS CENTRAL CA INNER WTRS BEYOND DAY 5.

.SEAS...THE 12Z ENP WW3 APPRS TO INITIALIZE WELL AGAINST 18Z SEA
STATE ANALYSIS. FOLLOWED CLOSE TO ITS GUIDANCE THRU 15Z SAT AND
THEN USED A 50/50 BLEND WITH 12Z ECMWF WAM TO 06Z MON AND BRFLY 75
PCT ENP/25 PCT EC WAM LATE SUN NIGHT AND MON BEFORE TRANSITIONING
TO 12Z ECMWF WAM MON NIGHT AND BYND.

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

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ900...OUTER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
     GALE POSSIBLE SUN NIGHT INTO MON.
.PZZ905...OUTER WATERS FROM CAPE SHOALWATER TO CAPE LOOKOUT...
     GALE POSSIBLE SUN NIGHT.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER BANCROFT. OCEAN PREDICTION CENTER.



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