Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 060344
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
744 PM PST THU MAR 5 2015

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

THE IR SAT IMG HAS ALMOST CLR SKIES OVR MOST OF THE SRN AND CNTRL
REGION WITH JUST A FEW CLDY AREAS OVR THE FAR NW PORTIONS OF THE
NRN WTRS. THERE IS NO INDC OF ANY LIGHTNG AND THE RADAR HAS NO
TSTMS CELLS OVR THE REGION AND EVEN WITHIN ITS VCNTY. AT 0000Z HGH
PRES 1026 MB OVR THE SRN WTRS HAS A RIDGE ACRS THE SRN AND CNTRL
FCST WTRS. ANOTHER HGH PRES 1029 MB JUST E OF THE FAR NRN WTRS HAS
ITS RIDGE ACRS THE REST OF THE NRN WTRS. INLAND TROF ALONG THE
COAST STRETCHES FROM SRN CAL AND ENDS NR THE NRN CAL STATE. JUST W
OF THE HGH PRES IS A LOW 997 MB WITH ITS CLD FRNT STRCHNG SW AND A
WRM FRNT STRCHNG NE AND LINKS WITH A CLD FRNT...W OF THE WASH
WTRS...THAT STRETCHES SW FROM A LOW PRES 1012 MB NR 55N130W.
FARTHER UPSTREAM IS STRNG HIGH PRES 1040 MB OVR THE CNTRL PAC. THE
PRES GRDNT IS VERY RELAXED OVR THE REGION AND THE MAX WINDS ARE
ONLY REACHING 15 KT. THE LAST R-SCAT PASS AT 1850Z HAD NO WINDS
ABOVE 10 KT OVR THE CNTRL REGION. BUOY 46005 W WA ABOUT 300 NM W
OF ABERDEEN HAS BEEN REPORTING 10 KT WINDS AND 5 FT SEAS IN THE
PREVIOUS 6 HRS. BUOY 46047 TANNER BANK ABOUT 120 NM W OF SAN DIEGO
HAD LESS THAN 10 KT WINDS AND 5 FT SEAS. THE SEAS PATTERN IS
EQUALLY MEDIOCORE OVR THE REGION RANGNG BTWN 3 AND 6 FT. THE LAST
JASON PASS OVR THE REGION WAS AT 05/1130Z AND HAD SEAS BTWN 4 AND
6 FT ACRS THE REGION. THE NWW3 MULTI GRID WV MDLS FITS WELL WITH
THE SEAS PATTERN OVR THE REGION BUT IS SLIGHTLY UNDERDONE IN THE
HGH SEAS WTRS BY ALMOST 3 FT. OTHERWISE NW3 HAS BEEN QUITE
CONSSTNT AND IN GUD AGRMNT WITH THE ECMWFAWVE

UPPRLVL CUTOFF HGH OVR THE CNTRL WTRS WITH RIDGE XNTDNG OVR THE
NRN WTRS. S OF THE UPPRLVL HGH IS SOME ENRGY THAT IS PART OF THE
BAND OF ENRGY THAT STRETCHES FROM A BACK HANGING TROF ALL THE WAY
FROM NRN ATLC ACRS THE NE US THRU THE MID ATLC STATES INTO THE SRN
MISS VALLEY AND EXITS THE S-WRN STATES INTO THE SRN WTRS. THE
ENERGY OVR THE SRN WTRS WILL BE CUT OFF AND SHIFT FARTHER S TO
LINGER OVR S OF CA LEAVING THE UPPRLVL HGH TO DOMINATE THE ENTIRE
FCST REGION. THE UPPRLVL RIDGE WILL PERSIST INTO THE XTNDD PRD
WITH NO ENERGY OVR THE REGION OR NR THE COAST. AS SUCH THE INLAND
TROF SHUD CONTNE TO WKN AND FRNTL SYS WILL BE BLOCKED FROM
REACHING THE FCST WTRS FROM THE W. THE UPPRLRVL HGH WILL
EVENTUALLY WEAKEN AND JUST LEAVE A RIDGE THAT WILL SLIGHTLY SHIFT
E TO ORIENT ITS AXIS ALONG THE COASTAL AREAS. THAT WILL ALLOW SOME
ENERGY AT THE END TO SHIFT E TWD THE REGION AND WILL ONLY IMPACT
THE WTRS IN THE LAST FCST PRD. THERFORE A MDL CHOICE SHUD BE ONE
THAT SUPPORTS A RELAXED PRES GRDNT THAT WILL KEEP WINDS BELOW GALE
FORCE THRU MOST OF THE PRD BUT LAST. THE LOCALLY WIND DRIVEN SEAS
SHUD REMAIN BELOW 10 FT WITH HGHR SEAS TO BE CONFINED TO THE WRN
WTRS DUE TO SWELLS THAT WILL BE GENERATED BY LOW PRES TO THE W OF
THE HGH PRES.

THE GLBL MDLS HV GENERALLY INTIALIZED WELL WITH THE CURR OBS AND
THEY ARE IN DECENT AGRMNT ESPCLY IN THE SHORT TERM. WITH LITTLE OR
NO MJR WX VARNS OVR THE REGION MDLS JUST HAVE TO AGREE ON THE
STRNGTH OF THE HGH PRES THAT WILL DOMINATE THE WX OVR WTRS. DIFFS
ARE VIVID TWD THE END OF FCST PRD AS MDLS DIFFER WITHIN 3 MB
MARGIN AND ONLY WITHIN 240 NM BTWN THE NRN MOST AND SRN MOST
CNTRS. THE CMC HAS THE SRN MOST CNTR AND IS ALSO THE WEAKEST WHILE
GFS THO BEING THE NRN MOST IS VERY CLOSE TO THE UKMETHR AND THE
ECMWFHR. THESE VRNS AS SO MINIMAL THAT THEY WILL HAVE ALMOST NO
IMPACT ON THE GENRAL FCST FOR EACH REGION AND SO WILL CONTINUE
WITH GFS AND NWW3 FOR SEAS. IN THE SHORT TERM HGH PRES OVR THE
CNTRL CAL WTRS WILL SHIFT INTO THE NRN CAL WTRS AND STILL KEEP ITS
RIDGE DOMINANCE OVR THE ENTIRE REGION AND THIS SENARIO WILL
PERSIST INTO THE XTNDD PRD. THE PRES GRDNT WILL REMAIN SLACK MOST
OF THE FCST PRD.

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

GRIDS THIS AFTN WL BE SMLR TO THE MORN PKG AND LAST SVRL SHIFTS.
WL USE 12Z GFS INTO 06Z MON...THEN SHIFT FCST TWD 12Z ECMWF
THEREAFTER. BLOCKING UPR RIDGE WL RMN STNRY ACRS THE ERN PAC THRU
LATE MON RESULTING IN MOSTLY LT/MOD WINDS AND SEAS THRUT THIS TIME
FRAME. NOTHING REMOTELY APRCHG GALE FORCE WIND CRITERIA IS XPCTD.

PATTERN FINALLY BEGINS TO SHIFT AT THE TAIL END OF FCST AND BYND
NXT WK AS DEEP H5 CUTOFF LOW BGNS TO FINALLY PROGRESS EWARD AS THE
UPR RIDGE SHIFTS INLAND. ECMWF IS PREFERRED HERE TO KEEP A SLIGHTY
WKR SOLN AS COMPARED TO THE GFS/GEM...WHICH INDC GRAD WINDS TO
30KT+ LATE TUE NGT AS THE SFC LOW MVS E-WARD TO A PSN ALNG 135W.
WHILE CONFDC IS HIGH THAT A PATTERN SHIFT / BROAD CUTOFF LOW WILL
APRCH THE RGN TUE NGT AND BYND...THERE IS NO CONFDC ON WHERE SVRL
LOW CENTERS EMBEDDED WITHININ THE LARGER CIRCULATION WL BE
LOCATED. BEING SO LATE IN THE FCST PERIOD NO NEED TO BE CONCERNED
WITH THESE DETAILS ATTM...AND USING 12Z ECMWF WL BRING ONE WEAK
LOW THRU THE WTRS WITH WINDS WELL BLO WIND WARNING CRITERIA.

SEAS...SIG WVHT GRIDS WILL BE BASED ON THE ABV. WL USE THE 12Z ENP
THRU 06Z MON THEN 12Z ECMWF WAM THEREAFTER.

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


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE POSSIBLE TUE NIGHT INTO WED.
.PZZ915...OUTER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE POSSIBLE TUE NIGHT INTO WED.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE POSSIBLE TUE NIGHT INTO WED.
.PZZ920...OUTER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE POSSIBLE TUE NIGHT INTO WED.
.PZZ925...OUTER WATERS FROM POINT ARENA TO PIGEON POINT...
     GALE POSSIBLE TUE NIGHT INTO WED.

$$

.FORECASTER MUSONDA/COLLINS. OCEAN PREDICTION CENTER.


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