

794 

AGPN40 KWNM 152110

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

210 PM PDT MON AUG 15 2016



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

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



OFFSHORE HIGH PRES IS LOCATED NEAR 39N139W THIS AFTN WITH A RIDGE

AXIS EXTENDING ACROSS THE PZ5 WTRS PER THE 18Z NCEP SFC ANALYSIS.

A 1010 MB LOW IS ANALYZED OVER NRN CA WITH AN ASSOCIATED TROF

EXTENDING THRU CENTRAL CA. SEASONAL NLY WINDS PREVAIL BTWN THESE

SFC FEATURES. A 1720Z ASCAT-B PASS SHOWED N TO NW WINDS 10 TO 20

KT OVER THE SRN CA WTRS. STRONGER WINDS ARE OCCURRING OFF THE SRN

OR/NRN CA COAST...AS A 1805Z ASCAT-A PASS REVEALED 20 TO 30 KT

WINDS OVER THE OFFSHORE WTRS WITH A FEW GALE BARBS NOTED NEAR THE

COAST.



THE 12Z MODELS CONTINUE TO SUPPORT AN EXTENDED PERIOD OF GALES OFF

THE NRN CA/SRN OR COAST TUE THRU WED NIGHT. SFC HIGH PRES WILL

MOVE N ROUGHLY ALONG 140W WHILE STRENGTHENING OVER THE NEXT COUPLE

DAYS...WHILE AN INLAND SFC TROF SHARPENS OVER CA. THE RESULTING PRES

GRADIENT WILL PRODUCE GALES BEGINNING TUE AFTN OVER THE SRN OR/NRN

CA COASTAL WTRS...EXPANDING INTO OUR OFFSHORE ZONES TUE NIGHT.

GIVEN MODEL CONSISTENCY NOTED OVER THE PAST COUPLE DAYS...CONFIDENCE

IS HIGH FOR GALES ESPECIALLY OVER THE INNER WTRS FROM PT ST GEORGE

TO PT ARENA. WILL CONTINUE TO USE A BLEND OF THE 12Z GFS 10M/30M

WINDS DURING THIS TIME...WHICH EXPANDS GALE COVERAGE TO INCLUDE A

SMALL PORTION OF THE INNER OFFSHORE WTRS FROM CAPE BLANCO TO PT ST

GEORGE AS WELL. GALES ARE EXPECTED TO PERSIST THRU WED INTO WED

NIGHT BEFORE THE SFC HIGH FINALLY BEGINS TO DRIFT W AND WEAKEN

SLIGHTLY ON THU. WEAK LOW PRES DVLPG OVER THE CENTRAL PZ6 WTRS ON

FRI WILL HELP TO FURTHER DISPLACE THE SFC RIDGE W OF THE AREA.



STILL MONITORING A SECOND POTENTIAL AREA OF GALES AS WELL OVER THE

FAR NRN PZ5 WTRS WED NIGHT. AS A SFC TROF ALONG THE WA COAST

EXPANDS N ACROSS VANCOUVER ISLAND... ANOTHER POCKET OF GALES MAY

DEVELOP WITHIN THIS ENHANCED GRADIENT. USING THE 10M/30M BLEND

REFERENCED ABOVE PRODUCED A BRIEF PERIOD OF GALES THAT JUST EXTEND

INTO THE FAR NRN PZ5 WTRS WED NIGHT. THIS REMAINS CONSISTENT WITH

OUR PREVIOUS FCST AND THE ENV CANADA FCST TO THE N OF THE AREA.



AGAIN...WITH GREAT MODEL AGREEMENT OVER THE OFFSHORE WTRS...SAW

NO REASON TO DEVIATE FROM THE 12Z GFS THRU THE PERIOD. THE 10M

WINDS WERE FAVORED OVERALL...EXCEPT FOR THE 10M/30M BLEND USED

FROM 18Z TUE TO 12Z THU DURING THE PERIOD OF ANTICIPATED GALES.



.SEAS...THE 12Z NWW3 WAS PREFERRED FOR MUCH OF THE PERIOD...EXCEPT

FROM 12Z TUE TO 12Z WED WHEN THE 12Z ECMWF WAM DID A BETTER JOB OF

BUILDING SEAS FASTER WITH THE GALES. HIGHEST SEAS OF 15 TO 16 FT

ARE EXPECTED WED OFF THE NRN CA COAST.





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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

.PZZ800...INNER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...

     GALE POSSIBLE WED NIGHT.

.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...

     GALE WED.



.PZ6 CALIFORNIA WATERS...

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

     GALE TUE NIGHT INTO WED. 

     GALE POSSIBLE WED NIGHT.



$$



.FORECASTER REINHART. OCEAN PREDICTION CENTER.

