Marine Interpretation Message
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
AGPN40 KWNM 210803
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
1203 AM PST SUN DEC 21 2014

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

THE LTST IR IMGRY INDC A LOW PRES SYS CTRD OVR THE GULFAK...WITH A
WKNG FRONT EXTENDING SE ALONG THE COAST AND INTO THE PZ5 OFSHR
WTRS. ASCAT FM 0420 UTC INDC A FEW GALES STILL ALNG THE
FRNT JUST W OF CAPE FLATTERY...AND CRNT SFC RPRTS SHOW ABT THE
SAME. THE WV IMGRY INDC A MID LVL TROF MOVG INTO THE NRN
COAST...WITH A NEG TILT...AS A SLOWLY AMPLIFYING RDG BUILDS JUST W
OF THE OFSHR WATERS. THE 00Z GFS WINDS ARE INIT WELL WHEN
COMPARED WITH THE DATA...AND INDC THE WNDS WL CONT TO WKN OVR THE
NEXT FEW HOURS AS THE BNDRY MOVES INLAND AND TO THE SE. GALES IN
THE PREV FCST FROM LAST NGT HAVE ENDED IN THE OFSHR WTRS...AND
ATTM PLANNING ON STARTING OFF WITH 25 KT. IN ADDITION...ANTHR WK
IMPULSE WL PASS TO THE N OF THE AREA TDA...AND INCRS THE WNDS TO
THE NW OF THE OFSHR WTRS. THIS SHUD KEEP WNDS OVR THE FAR NW
WATERS TO 25 KT THRUT THE DAY. FURTHERMORE...HIGH PRES BLDG TO THE
W OF THE OFSHR WTRS WL INTERACT WITH A DVLPG TROF ALNG THE CAL
COAST...AND INCRS THE WNDS OVR THE SRN CAL WTRS. PLANNING ON GOING
TO 30 KT W OF THE CHANNEL ISLANDS TDA INTO TNGT...THEN EXPANDING
THEM TO THE N WITH THE THE TROF AS IT EXTENDS.

THE BIGGEST FCST PRBLM CONT TO OCCUR ON MON INTO TUE...WITH LOW
PRES PASSING TO THE NW OF THE OFSHR WTRS. THE GFS HAS BEEN VRY
CONSISTENT WITH THE MERGING OF 2 SHRTWVS SUN NGT INTO MON...THEN
DVLPG A VRY STG SFC LOW WITH HURCN FRC WNDS BY 12Z TUE OVR THE ERN
GULFAK. THE ECMWF HAD BEEN SPLITTING THE ENERGY IN TWO...AND
KEEPING THE SYSTEM MUCH WKR. THE GFS HAS BEEN VRY CONSISTENT WITH
THE CONSOLIDATED SYSTEM OVER THE PAST FEW DAYS...AND THE OOZ RUN
HAS NOT CHANGED MUCH FROM PREV RUNS. THE 00Z ECMWF/UKMET/GEM HAVE
ALL TRENDED STGLY TWD THE GFS...ALTHO NOT QUITE AS STG. ALL BUT
THE GEM IS SHOWING A STG UPR LOW AND SHRTWV AT 12Z TUE...BEFORE
PART OF THE ENERGY SPLTS OFF AND HEADS INLAND. AS A
RESULT...PLANNING ON FLWG GFS SOLN WITH THIS SYS...WHICH GRAZES
THE NW CRNR OF THE WAS WTRS WITH GALES MON NGT. CONFDC IS
MDT...BUT CONFDC IS HIGH WITH GFS SO WL ADD WRNG TO FCST.

IN THE EXTENDED...THE MDLS ALL AMPLIFY THE RDG AS THE UPSTREAM
TROF IS CARVED OUT BY THE ENERGY ASSOC WITH THE CRNT SYS OVR THE
AREA. THE 00Z MDLS AGREE FAIRLY WELL ON THE PTTN...AND ALL ALSO
SHOW AN AMPLIFYING PRES GRAD ALNG THE COAST AS THE HIGH BUILDS TO
THE W AS THE CSTL TROF EXTENDS N AND STRENGTHENS. CONFDC IS MDT
WITH THE MDL GALES SHOWN ON THU INTO THU NGT NEAR CAPE
MENDOCINO DUE TO THE OVERALL GUD MDL AGRMT...AS A WK CD SURGE IS
XPCTD TO DESTABILIZE THE ENVRNMT...ALLOWING STGR MXG. THE ONLY
OUTLIER IS THE GEM...WHICH WKNS THE RDG IN THE E PAC DUE TO THE
DIIF IN HANDLG OF A CUTOFF LOW NR HAWAII. THE GEM HAS BEEN VRY
ERRATIC...SO NO CONFDC IS PLACED WITH IT. ATTM PLANNING ON ADDING
GALES IN THE NRN CAL WTRS FOR THU INTO THU NGT AS A RESULT OF GUD
MDL AGRMT AND A SYNOP SITUATION THAT WOULD SUPPORT THEM. OTRW
PLANNING ON FLWG 00Z GFS FOR THE RMNDR OF THE FCST PD.

SEAS...THE 00Z NWW3 AND ECMWF WAM ARE INIT OK...BUT DVRG A BIT
IN THE WAS WTRS MON INTO TUE. THE DIFF IN WIND INTNSTY BTWN THE
ECWMF AND GFS CAUSED DIFFS IN THE ASSOC WAV MDLS. SIMLR TO THE WX
MDLS...THE 00Z ECWMF WAM TRENDED SHARPLY TWD THE NWW3. THE NWW3
HAS BEEN SHOWING GUD RUN TO RUN CONSISTENCY WITH THE WAVE HTS...SO
ATTM PLANNING ON FLWG NWW3 FOR THE FCST.

GRIDS...00Z GFS 30M WINDS WL BE USED THRUT THE FCST PD...AND 00Z
NWW3 WL BE USED FOR THE SEAS.

.EXTRATROPICAL STORM SURGE GUIDANCE...

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ900...OUTER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
     GALE MON.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE POSSIBLE WED NIGHT INTO THU NIGHT.
.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...
     GALE POSSIBLE THU.

$$

.FORECASTER KELLS. OCEAN PREDICTION CENTER.



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.