Marine Interpretation Message
Issued by NWS

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000
AGPN40 KWNM 291516
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
816 AM PDT TUE JUL 29 2014

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

THE IR SAT IMG SHOW NO THICK CONV CLDS OVR THE REGION XCPT THE FAR
SRN PART THAT HAS CLDS THAT HAV XTNDD N THAT ARE ASSCTD WITH TS
HERNAN. THE RADAR SHOW NO TSTMS CELLS OVR THE REGION AND EVEN THE
ADJC COASTAL REGIONS. AT 1200Z HGH PRES 1025 MB W OF THE CNTRL
REGION IS STILL XTNDG RIDGES INTO THE NRN AND SRN WTRS. LOW PRES
1012 MB N OF THE REGION HAS A FRNT STRCHNG SE THAT ENTERS WASH
WTRS AND THEN CURVES SW. INLAND LOW PRES 1014 MB OVR AZ HAS A TROF
XTNDG NW ACRS CA. TS HERNAN S OF THE REGION MOVING IN THE GENERAL
NW DIR AND MORE INFO CAN BE FOUND WITH THE NHC. THE PRES GRDNT IS
VERY WEAK AND THE MAX OBS WINDS ARE ONLY 15 KT. THE LAST ASCAT
PASS OVR THE REGION WAS AT 0521Z AND HAD NO WINDS ABOVE 15 KT. THE
SEAS RANGE BTWN 4 AND 7 FT WITH HGHST SEAS OVR THE ERN PARTS OF
THE NRN CAL WTRS. THE NWW3 MULTI GRID FITS FAIRLY WELL WITH THE
OBS SEAS AND IT HAS BEEN QUITE CONSSTTNT. THE GLBL MDLS HV
INITIALIZED WELL AND ONLY HV THE HGH PRES TO AGREE ON. WILL STAY
WITH GFS FOR THIS UPDATE. IN THE SHORT TERM HGH PRES WILL REMAIN
ANCHORED TO THE W AND STILL MAINTAIN A RIDGE ACRS THE REGION WITH
A QUITE SLACK PRES GRDNT. THE WINDS WILL REMAIN BELOW GALE FORCE
IN THE FRCST REGIONS.

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

06Z NCEP ANAL HAS HIGH PRES CNTR JUST W OF NRN CA OFSHR AREA WITH
WK RDG ACRS PZ5 AREA WHILE INVERTED TROF REMAINS OVR CA AND N INTO
WRN OREGON. ASCAT-B PASSES FM 0436Z AND 0618Z RETURNED WNDS 17 TO
23 KT FM CSTL WTRS OFF CAPE SHOALWATER S OVR ERN OREGON OFSHR AND
CSTL WTRS BUT PASSES MISS CENTRAL AND NRN CA INNER ZONES AND CSTL
WTRS. THESE CONDS ARE LESS THAN EARLIER PASSES AND REFLECT WKNG OF
GRADIENT AS TROF WKNS. NEW FCST STARTING WITH MAX 25 KT OVR SML
AREA OFF NRN CA OR FAR SE OREGON. 00Z GFS 30M WNDS APPR
REPRESENTATIVE.

SLOW CHANGING PATTERN EXPECTED OVR EPAC OVR NEXT 5 DAYS AS AN UPR
LOW IN ERN GLF OF AK TODAY ROTATES BACK TWD W AND SW LATER TODAY
INTO FRI AS ANOTHER SHRTWV DROPS S OUT OF AK ON ITS W SIDE. THIS
ALLOWS AN UPR RDG OVR WRN U.S. INTO SW CANADA TO STRENGTHEN...AND
AS A RESULT THE INVERTED TROF OVR CA INTO SW OREGON AFTER INITL
WKNG TODAY...STRENGTHENS WED INTO SAT...AND WNDS INCRS OFF NRN
CA/SRN OREGON TO 25-30 KT BY THU AND SPREAD N AND S INTO SAT. ONE
WRINKLE IS THAT 00Z GFS LIKE PREVEIOUS RUN DVLPS GALE FRC BL WNDS
IN NRN CA AND FAR SE OREGON MAINLY CSTL AREAS LATER FRI BUT OTHER
MDLS ARE NOT ON BOARD...WITH 00Z UKMET BACKING OFF FM ITS
PREVIOUSLY FCST GALE SAME AREA AND AND THE USUALLY ROBUST CMC
GLOBAL ONLY SHOWS MAX 1000 MB WNDS OF 35 KT. 00Z ECMWF/UKMET 10M
WNDS PEAK AT 30 KT AT TIMES LATE FRI INTO SAT. MDLS ARE OTRW IN
GOOD AGRMT AND SPRT GFS. CONTG WITH 00Z GFS 30M WNDS FOR WND
GRIDS.

SEAS...00Z WAVE WATCH III APPRS WELL INITIALIZED AND WILL USE FOR
FCST TO START FIRST PRD. BEYOND THAT MDLS SHOW MINOR DIFFERENCES
AND AGREE WI A FT FOR MAX SEAS. USED 50/50 BLEND FOR SUN AFTN TO
THU AFTN AND THEN 00Z ENP WW3 BEYOND THAT.

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


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER MUSONDA/BANCROFT. OCEAN PREDICTION CENTER.


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