

957 

AGPN40 KWNM 171542

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

842 AM PDT WED AUG 17 2016



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT

.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.



THE SAT IMG INDC A RIDGE TO THE W OF THE FORECAST WATERS. ALL THE

OBSERVATIONS INCLUDING THE EARLIER ASCAT PASS AT 0506Z THIS

MORNING SHOW MAX WINDS IN GALE FORCE RANGE OVER THE NRN CA AND FAR

SRN OR WATERS. AT 12Z THE NCEP MAP HAS HIGH PRES CENTER 1034 MB

NEAR 50N135W AND 1033 MB NEAR 42N140W WITH A RIDGE EXTENDING SE

INTO THE SRN AND ANOTHER INTO THE NRN WATERS. INLAND LOW PRES 1008

MB OVER CA WITH TROFS EXTNDG NW AND SE. ANOTHER INLAND LOW PRES

1012 MB OVER WA HAS ITS TROF EXTEDNING NW PASSING JUST N OF THE

WATERS. THE PRES GRADIENT IN TE VICINITY OF THE TROFS IS FAIRLY

TIGHT ESPECAILLY OVR THE CENTRAL WATERS WHERE THE WINDS ARE

ALRAEDY IN GALE FORCE RANGE. THE SEAS HAVE ALSO PEAKED AT 13 FT

OVER THE CENTRAL WATERS WITH ASECONADRY PEAK 10 FT OVER THE NE WA

WATERS. OTHERWISE SEAS RANGE BETWEEN 6 AND 9 FT ELSEWHERE. THE

NWW3 MULTI GRID FITS WELL WITY THE OBSERVED SEAS PATTERN.



THE GLOBAL MODELS HAVE INITIALIZED WELL AND THEY CONTINUE TO BE

IN GOOD AGREEMENT ESPECIALLY IN THE SHORT TERM. JUST MINOR

DIFFERENCES IN THE CENTRAL PRES VALUE FOR THE INLAND LOW WHERE

EVERY MODEL HAD A VALUE HIGHER THAN THE OBSERVATION BUT WITHIN 3

MB. OTHERWISE THE SYNOP PATTERN REMAINS VERY CLOSE TO THE

OBSERVATIONS. FOR THIS UPDATE WITH STAY WITH GFS. IN THE SHORT

TERM HIGH PRES WILL PERSIST TO THE W OF THE REGION WHILE THE

INLAND TROF WIL ALSO PERSIT AND THAT WILL KEEP GALE FORCE WINDS

OVER THE CENRAL WATERS AND WINDS WILL ALSO BE ELAVATED OVER THE

NRN WATERS BUT WITH LOW CONFDC WILL KEEP IT BELOW GALE FORCE FOR

NOW AND WILL RE-EVALUATE IN THE NEXT PACKAGE.



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PREVIOUS DISCUSSION...



THE 06Z SFC ANALYSIS INDICATED HIGH PRES CENTERED NEAR 42N141W

WITH RIDGE EXTENDING N INTO GULF OF AK ALONG 140W. TROUGH EXTENDED

ALONG THE CA COAST N TO FAR SRN OREGON COAST. ASCAT PASS FROM LATE

TUE EVENING MISSED THE S OREGON/N CA COASTAL AND E PORTION OF

OFFSHORE WATERS...HOWEVER RSCAT PASS FROM 0348Z DID INDICATE AREA

OF GALES OVER S OREGON AND N CA COASTAL WATERS EXTENDING TO BORDER

OF COASTAL/OFFSHORE WATERS...WITH LARGE AREA OF 30 KT COVER MOST

OF INNER PORTION OF N CA AND S OR WATERS.



THE 00Z MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT DURING THE

ENTIRE FCST PERIOD. THE MAIN FOCUS IS DURING THE SHORT TERM PERIOD

THROUGH LATE TONIGHT...MAINLY OVER THE N CA WATERS. THE 00Z

GFS/UKMET/ECMWF AND GEM CONTINUE TO INICATE GALES EXPANDING INTO

THE N CA OFFSHORE WATERS TODAY AND CONTINUING INTO THIS EVENING

BEFORE DIMINISHING ALL AREAS BY THU MORNING. OVERALL...THE GFS 10M

WINDS LOOK REASONABLE AND PLAN ON USING THESE TO POPULATE THE WIND

GRIDS DURING THE PERIOD. THIS WILL RESULT IN NO CHANGES TO

EXISTING WARNING HEADLINES. LOOKING AHEAD TO THU AND BEYOND...THE

LOW PRES OVER N CA INTERIOR WILL WEAKEN WHILE HIGH PRES OFFSHORE

ALSO WEAKENS. THIS WEAKER GRADIENT WILL RESULT IN WINDS REMAINING

BELOW GALE FROM THU THROUGH THE END OF PERIOD. 



.SEAS...THE 06Z SEA STATE ANALYSIS INDICATED THAT OBSERVED SEAS

CONTINUE TO MATCH UP WELL WITH THE MWW3/ECMWF WAM GUIDANCE AND

WERE WITHIN A FT OF THE OBS. BUOY 46244 NW OF EUREKA WAS REPORTING

12 FT AS OF 06Z...AND WENT WITH 13 FT MAX ON ANALYSIS. PLAN ON

USING THE MWW3 TO POPULATE THE WAVE GRIDS THROUGH THE PERIOD AS IT

IS CLOSE TO THE EMCWF WAM VALUES. 



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...

     GALE TODAY INTO TONIGHT. 



$$



.FORECASTER MUSONDA/KOSIER. OCEAN PREDICTION CENTER.

