

574 

AGPN40 KWNM 260210

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

710 PM PDT THU AUG 25 2016



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

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



NO SIGNIFICANT CHANGES TO THE FORECAST EXPECTED IN THE UPCOMING

PACKAGE.



SEAS...WWIII ENP ABOUT 1 FT UNDERDONE OVER THE NW WATERS. MADE

SLIGHT MODIFICATIONS TO THE WAVE GRIDS TO REFLECT THIS.

OTHERWISE...WAVE GRIDS LOOK GOOD WHEN COMPARED TO LATEST SFC OBS.



-----------------------------------------------------------------

PREVIOUS DISCUSSION...



THE ASCAT PASS FROM 18Z SHOWS WINDS 20-25 KT ACROSS THE WA/OR AND

NRN CA WATERS WITH LIGHTER WINDS S OF CAPE MENDOCINO. MAX SEAS AS

INDICATED BY RECENT OBS ARE 10-11 FT OVR WRN WA WATERS. BUOY

46005 RPT 10 FT AT 19Z. THE CURRENT UPR LEVEL PATTERN CONSISTS OF

AN ELONGATED RIDGE AXIS EXTENDING EWRD INTO THE WA/OR WATERS WHILE

AN ARE OF TROFFINESS PERSISTS OVER THE SRN MIM AREA EXTENDING INTO

THE CENTRAL CA WATERS. ON DAYS 2-5 A SERIES OF S/WVS WILL DIG SE

FROM ALASKA AND ROTATE INTO WRN CANADA OVR THE NEXT 24 HRS S/WV

ENERGY WILL DIG SE FORM ALASKA...EVENTUALLY CARVING OUT A CLOSED

UPR LOW ALONG THE WRN CANADA CST...EVENTUALLY MOVING INTO THE WA

WATERS. THE OVERALL SFC PATTERN WILL REMAIN PRETTY WEAK AS WINDS

ARE NOT EXPECTED TO EXCEED 25 KT ACROSS THE REGION THROUGHOUT THE

FCST PERIOD. THE CURRENT NRLY WINDS TO 25 KT OVER THE WA/OR WATERS

WILL GRADUALLY DIMINISH DURING THE NEXT 48 HRS AS THE HIGH PRES

CENTER THAT HAS PERSISTED W OF THE WATERS WILL SLOWLY SHIFT

FURTHER W...WEAKENING THE GRADIENT. LATER IN THE WEEK HIGH PRES

WILL BUILD EWRD TOWARDS THE CENTRAL CA WATERS. THE COMBINATION OF

THE HIGH PRES AND INLAND CALIFORNIA TROF WILL INCREASE THE

GRADIENT OVER THE PREFERRED AREAS FROM PT CONCEPTION TO PT

REYES...WITH MAX WINDS LIKELY OCCURRING IN THE COASTAL ZONES. FOR

THE MOST PART THE 12Z GLOBAL MODELS ARE IN PRETTY GOOD AGREEMENT

THROUGHOUT THE FCST PERIOD...WITH SOME MINOR DIFFERENCES. GIVEN

HOW WEAK THE WINDS ARE EXPECTED TO BE THIS SHOULDN'T CAUSE A SIG ISSUE.

WILL MAINTAIN SIMILAR CONTINUITY AS THE ORV FCST AND POP THE WIND

GRIDS WITH THE GFS THROUGH 12Z SUN...THEN TRANSITION TO THE ECMWF

FOR THE REMAINDER OF THE PERIOD.



SEAS...BOTH THE ENP AND WAM WERE INITIALIZED PRETTY WELL ACROS THE

OFFSHORE WATERS. FURTHER W OVR THE MIM AREA THE ENP IS RUNNING

TOO HIGH...WHEREAS THE WAM IS MORE IN LINE WITH THE CURRENT OBS.

FOR THAT REASON WILL POP THE WAVE GRIDS USING THE WAM TRHOUGH THE

REMAINDER OF TODAY...THEN TRANSITION TO A 50/50 BLEND OF THE TWO

MODELS THROUGH SAT NIGHT...THEN FINISH BY POP WITH THE USING THE

WAM FOR THE REMAINDER OF THE 7 DAY PERIOD.



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

     NONE.



$$



.FORECASTER ACHORN/SHAW. OCEAN PREDICTION CENTER.

