Marine Interpretation Message
Issued by NWS

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000
AGPN40 KWNM 041422
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
722 AM PDT TUE AUG 4 2015

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

12Z OPC SFC ANALYSIS SHOWS A LOW PRES TROUGH EXTENDING NE TO SW
OVER THE NRN CA WATERS...W/A HIGH PRES RIDGE OVER THE REMAINDER OF
THE PZ5/PZ6 WATERS. WILL NOT MAKE SIGNIFICANT CHANGES TO THE
ONGOING FORECAST IN THIS INTERMEDIATE UPDATE GIVEN CLOSENESS OF
THE 06Z GFS TO ITS 00Z GFS RUN.

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

THERE WAS AN ASCAT PASS AT 0550Z WITH A SWATH ACRS MUCH OF THE ERN
AREAS OF THE OFFSHR WTRS. WINDS WERE TO 25 KT OVR THE ERN EDGE OF
THE SWATH OVR THE SRN CA WTRS WHICH FIT WELL WITH BUOY OBS OVR
THIS REGION. ALSO OVR THE FAR NERN AREAS OF THE NRN WA WTRS WINDS
WERE TO 25 KT. SEAS ACRS THE OFFSHR WTRS WERE CLOSE TO BOTH THE
WWIII ENP AND ECMWF WAM...ALTHO OVR AND NR THE WA WTRS SEAS WERE
SVRL FT HIGHER THAN GUID. AT 09Z JUST N OF THE WA WTRS BUOY OBS
HAD 9 FT WHILE GUID HAD 7 FT.

A BROAD AREA OF HIGH PRES RMNS W OF THE WA/OR/NRN CA OFFSHR WTRS
AND WL BE BUILDING EWD OVR THE WTRS TDA THRU THU NGT...WHILE
GRADUALLY DRIFTING EWD AND SHIFTING SWD TO THE W OF THE OR/NRN CA
WTRS. AS MENTIONED ABV STGST WINDS EARLY THIS MRNG WERE OVR THE
NERN WA AND ERN AREAS OF THE SRN CA WHERE WINDS WERE TO 25 KT.
WINDS GRADUALLY DMNSH OVR THESE AREAS...AND BEGIN TO STRENGTHEN
OVR THE ERN OR/NRN CA WTRS LATER THIS AFTN INTO TNGT AS COASTAL
TROF DVLPS. MDL GUID LOOKS SMLR TO EARLIER GUID WITH UKMET NOT AS
STG WITH PRES GRAD AS THE GFS/ECMWF WHICH ARE SMLR WITH GALES
DVLPG OVR NRN CA AND INTO THE SERN OR WTRS LATER THU INTO THU NGT.
WL MAINTAIN MARGINAL GALES OVR THIS REGION INTO THU NGT. WL USE
THE GFS WITH SUPPORT FM THE ECMWF THRU THE FCST PD. THERE ARE SOME
DIFFS BY SAT NGT WITH LOW PRES THAT APPROACHES FM THE N WITH THE
UKMET/ECMWF SMLR WITH TRACK OF LOW WHILE THE GFS IS LESS WELL
DEFINED. DIFFS ARE NOT GREAT...SO WL NOT MAKE ANY ADJSTMTS FM GFS
OUTPUT.

SEAS...BOTH THE MULTIGRID WWIII AND ECMWF WAM LOOK SMLR WITH SEAS
THRU THE FCST PD. AS MENTIONED EARLIER SEAS INIT ARE SVRL FT
HIGHER THAN GUID AT 06Z INVOF WA WTRS AND WL MAKE SLGT ADJSTMTS
TO ACCOUNT FOR THIS TDA. OTW WL USE A 50/50 BLEND OF THE WWIII AND
ECMWF WAM THRU THE FCST PD.


EXTRATROPICAL STORM SURGE GUIDANCE...N/A.


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE POSSIBLE THU INTO THU NIGHT.

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

$$

.FORECASTER HOLLEY/ROWLAND. OCEAN PREDICTION CENTER.



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