Marine Interpretation Message
Issued by NWS

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000
AGPN40 KWNM 190312
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
712 PM PST THU DEC 18 2014

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

CRNT GOES IR IMGRY AND THE LTST NCEP SFC ANALYS INDC A STG LOW
PRES SYS IN THE E PAC...AND RSCAT FM 2345 UTC INDC GL FRC WINDS
ALNG THE COAST E OF THE OFSHR WTRS. THE EARLIER ASCAT FM 1930 UTC
INDC A LRG AREA OF 45 KT WNDS IN THE STGR CHANNELING BTWN THE FRNT
AND THE CANADIAN COAST...AND CRNT SFC RPRTS STILL INDC GALES ALNG
THE COAST. THE 18Z GFS WINDS ARE INIT OK WHEN COMPARED WITH THE
DATA...AND INDC THE WINDS WL DCRS TNGT AS THE BNDRY MOVES INLAND.
MOST OF THE GALE FRC WINDS HAVE CLEARED THE OFSHR WTRS...WITH ONLY
A FEW REMAINING AT 00Z OVR THE FAR ERN NRN CAL AND ORE WTRS...SO
WL START OFF AT SUB GALE.

THE 12Z/18Z MDLS AGREE ON THE ASSOC STG LOW CTR PASSING TO THE NW
OF THE OFSHR WTRS TNGT INTO FRI...WITH STG CAA S OF THE LOW INCRSG
WINDS TO GL FRC JUST NW OF THE WAS WTRS. THE MDLS MOSTLY CAP WNDS
AT 30 KT IN THE OFSHR WTRS IN THIS FLOW...WHICH WAS GENLY FLWD IN
THE PREV FCST...SO WL CONT IN THE UPDATE PKG.

OTRW...THE MDLS AGREE FAIRLY WELL IN THE SHORT TERM...WITH THE
BIGGEST FCST PRBLM IN THE EXTENDED WITH THE GFS REMAINING AN
OUTLIER AFTER SUN NGT. THE 18Z GFS DID NOT TREND TWD THE MDL
CONSENSUS...AND CONT TO HANDLE THE SHRTWV ENERGY MOVG OVR THE TOP
A BLDG E PAC RDG DIFFERENTLY. THE PREV FCST FAVRED THE 12Z ECMWF
AFTER SUN NGT...WHICH LOOKS RSNBL GIVEN THE OUTLIER 18Z GFS
SOLN...SO NOT PLANNING ON MKG ANY SIG CHANGES IN THE UPDATE PKG
ATTM.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

18Z NCEP FINAL ANAL HAS A CDFNT AND WRMFNT OVR PZ5 WTRS AND AN
OCFNT N OF AREA EXTENDING NW AND W INTO A STORM CNTR 51N148W
ENTERING SRN GLF OF AK. 18Z AND 1930Z ASCAT-B PASSES INDC GALES FM
FLORENCE OR AREA IN OUTER WTRS NE AHD OF FNT THRU ERN WA WTRS AND
N OF AREA WHERE 45 KT RETRIEVALS NW VANCOUVER ISL AREA WOULD
SUGGEST STORM FRC WNDS. IN THE MORE UNSTABLE W TO SW CYC FLOW BHND
FNT AROUND SE SIDE OF STORM CNTR RERIEVALS UP TO 35 KT APPEAR W OF
OREGON AND NRN CA WTRS. CONVECTION BHND FNT ASCD WITH DEEP UPR
TROF ASCD WITH STORM HAS CONTAINED SOME LTNG IN LTNG IMAGERY ASCD
WITH THIS CONVECTION. MDLS INDICATING A FEW TSTMS IN INSTABLE FLOW
MOVG INTO WTRS TONIGHT INTO FRI...SO WILL CONT TO MENTION IN SOME
OF PZ5 ZONES. THE 12Z GFS 30M WNDS APPR REPRESENTATIVE. CURRENT
FCST APPRS ON TARGET.

FOR THE FCST THE CURRENT FNTL SYSTEM APCHS CST EARLY TONIGHT AND
DID MINOR EDITING OF WND GRIDS TO EXTEND PREFNTL GALES INTO FAR NE
NRN CA WTRS...NOT TAKING THEM OUT OF INNER WTRS ZONE AS THEY WILL
BE BRIEF. GALES SHOULD END EARLY TONIGHT AS FNT MOVS INLAND AND
TRAILING PORTION WKNS OVR NRN AND CNTRL CA WTRS. CURRENT LOW PRES
IS EXPECTED TO WKN IN GLF OF AK TONIGHT AND FRI AND BE REPLACED BY
ANOTHER UPSTRM DVLPMT...AS LOW PRES AREAS S OF ALUTNS CONT TO TROW
OFF TRPL PT LOWS MOVG RPDLY TWD GLF OF AK AS STRONG WRN AND
CENTRAL PAC JET NOSES ENE. SOME MDL DIFFERENCES DVLP SAT AND BYND AS
12Z UKMET MOVS A STG LOW NEAR WA WTRS SAT WHILE ECMWF HAS BACKED
OFF AND 12Z GEM SPRTS GFS. CONT TO FAVOR 12Z GFS WHICH TAKES MAIN
LOW FARTHER NW FRI NIGHT AND SAT SENDING ANOTHER FNTL SYSTEM OF
SIMILAR STRENGTH TO PREVIOUS INTO OFSHR WTRS FRI NIGHT INTO
SAT...WITH ANOTHER ROUND OF GALES IN PZ5 WTRS. THE ASCD CDFNT MOVS
INTO PZ5 AREA AND SLOWS AS AN E PAC BROAD UPR RDG BUILDS SAT NIGHT
INTO MON BEFORE BGNG TO WKN BY TUE NIGHT. GFS DVLPS A STRONG LOW
MOVG ALG FNTL BNDRY TO NEAR THE WA WTRS LATER MON INTO EARLY TUE
WHILE 12Z GEM TAKES SUCH A LOW FARTHER NW AND UKMET IS WEAKER. 12Z
GEFS ENSEMBLE SHOWS NO MEMBERS NR WA WTRS...SO PREFER WEAKER ECMWF
FOR MON AFTERNOON AND BYND. OTRW USING 12Z GFS 30M WNDS FOR FCST
THRU SAT NIGHT AND TRANSITION TO 10M WNDS SUN INTO MON AS MORE
STABLE SW FLOW OR WK RIDGING DVLPS. WNDS TO 25 KT PSBL W OF A
DVLPG CSTL TROF SRN/CENTRAL CA WTRS LATE SAT INTO TUE AS HIGH PRES
BLDS TO N. POPULATED WITH 12Z ECMWF LATE MON AND BYND.
MEMBERS SL

SEAS...12Z NWW3 AND ECMWF WAM ARE INIT OK AND ARE IN GUD AGRMT IN
THE SHORT TERM...BUT DIFFER UP TO 3-4 FT WITH WLY SWELL MOVG INTO
WTRS FM BIG STORM TO NW BEGINNING TONIGHT...SO TOOK 50/50 BLEND OF
MDLS TONIGHT INTO MON BEFORE TRANSITIONING TO 12Z ECMWF WAM.

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

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ800...INNER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
     GALE FRI NIGHT INTO SAT.
.PZZ900...OUTER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
     GALE FRI INTO FRI NIGHT.
.PZZ805...INNER WATERS FROM CAPE SHOALWATER TO CAPE LOOKOUT...
     GALE FRI NIGHT INTO SAT.
.PZZ905...OUTER WATERS FROM CAPE SHOALWATER TO CAPE LOOKOUT...
     GALE FRI NIGHT INTO SAT.
.PZZ810...INNER WATERS FROM CAPE LOOKOUT TO FLORENCE OR...
     GALE FRI NIGHT INTO SAT.
.PZZ910...OUTER WATERS FROM CAPE LOOKOUT TO FLORENCE OR...
     GALE FRI NIGHT INTO SAT.
.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE FRI NIGHT INTO SAT.
.PZZ915...OUTER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE FRI NIGHT INTO SAT.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER KELLS/BANCROFT. OCEAN PREDICTION CENTER.



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