Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 210345
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
845 PM PDT WED AUG 20 2014

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

00Z NCEP SFC ANAL SHOWS A WRM FNT ENTERING PZ5 AREA FOLLOWED
CLOSELY BY A CDFNT...WITH LOW PRES CNTRD TO NW NEAR 52N140W. WITH
SYSTEM WKNG AS IT PASSES OVR UPR RDG THE LOW IS EXPECTED TO DSIPT
AS IT ENTERS WA WTRS BY THU AFTN WHILE CDFNT MOVS THRU PZ5 AREA
AND DSIPTS LATER THU. AFTER TEMP WKNG THE HIGH PRES TO THE W
REBLDS EWD LATER THU INTO FRI NIGHT AND PERSISTS W OF WTRS THRU
MON NIGHT. LATEST MDLS REMAIN IN GOOD AGRMT AND 18Z GFS IS
CONSISTENT WITH ITS PREVIOUS RUN. CHOSE TO POPULATE WND GRIDS AS
BLEND OF TWO THIRDS 18Z GFS 30M WNDS AND ONE THIRD GFS 10M WNDS
WHICH APPRS TO BE CLOSE MATCH TO OBSVD CONDS AT 00Z AND EARLIER
19Z ASCAT WNDS.

SEAS...INITIALIZING 7 TO 8 FT OR LESS ACRS AREA IN 00Z SEA STATE
ANAL WHICH IS CLOSE TO 18Z ENP WW3 AND 12Z ECMWF WAM. POPULATED
WITH 18Z ENP WW3 FOR EVENING UPDATE.
-----------------------------------------------------------------
PREVIOUS DISCUSSION...

SUMMARY...THE 12Z SFC ANALYSIS SHOWS LOW PRES CNTRD NW OF THE
WASH/ORE WTRS...WITH A WARM FRONT EXTENDING SE. A HI PRES RDG
PREVAILS JUST W OF THE OFSHR AREAS...WITH A LOW PRES TROF NEAR THE
CALIF CST. THE LOW NW OF THE WASH/ORE WTRS WILL MOVE SE THIS EVNG INTO
THU WITH A WKNG COLD FRONT PASSING ACROSS THE WATERS...THEN STALL
AND DSIPT OVER THE SRN ORE WATERS THU NIGHT. THE RDG WILL THEN
BUILD E AND NE FRI INTO MON AS THE COASTAL TROF STRENGTHENS.

MODELS...THE 12Z MED RNG MDLS ARE ALL VRY GUD AGREEMNT THRU THE
FCST PRD...AND THE MDLS KEEP THE WINDS SUB-GALE OVER ALL OF THE
ZONES DURING THE FCST PRD. WILL USE THE REPRESENTATIVE GFS 10M TO
POPULATE THE WIND GRIDS THRU THE PRD. AM NOT PLANNING TO MAKE ANY
SIGNIF CHANGES TO THE CURRENT FCST TREND.

.SEAS...18Z RP1 SEA STATE ANALYSIS SHOWS THAT OBSERVED SHIP AND
BUOY OBS ARE GENERALLY WITHIN A FOOT OF THE MULTIGRID WW3 AND ECMWF
WAM WAVE HT VALUES. SINCE THE 12Z GFS IS BEING USED FOR THE WIND
GRIDS...WILL USE THE ENP VERSION OF THE 12Z MWW3 MDL FOR THE WAVE
HT GRIDS. LONGER PERIOD SWELL FROM T.S. LOWELL IS EXPCTD TO ENTER
THE SRN PZ6 ZONES DURING THE THU THRU SUN NITE TIMEFRAME.

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

.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
     NONE.

$$

.FORECASTER BANCROFT/SCOVIL. OCEAN PREDICTION CENTER.



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