

318 

AGPN40 KWNM 151457

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

757 AM PDT MON AUG 15 2016



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

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



A 1026 MB HIGH PRES CENTER IS ANALYZED W OF THE WTRS NEAR 38N140W

THIS MORNING ACCORDING TO THE 12Z NCEP SFC ANALYSIS. A 1009 MB LOW

IS LOCATED OVER CENTRAL CA WITH A SFC TROF EXTENDING N ACROSS NRN

CA INTO SRN OR. AN EARLIER ASCAT PASS DEPICTED 20-30 KT NLY WINDS

OFF THE NRN CA COAST...HIGHEST OVER THE COASTAL WTRS...WHICH

MATCHED UP WELL WITH THE INHERITED FCST GRIDS. WITH NO SIGNIFICANT

CHANGES NOTED IN THE 06Z GFS...WILL ONLY MAKE MINOR ADJUSTMENTS TO

THE NEAR TERM GRIDS WITH THIS MORNING UPDATE. ANY GALES THAT

DEVELOP THIS AFTN SHOULD REMAIN CONFINED TO THE COASTAL WTRS.



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

PREVIOUS DISCUSSION...



THE 06Z SFC ANALYSIS INDICATED HIGH PRES CENTERED NEAR 37N142W

WITH RIDGE EXTENDING NE TO THE WA/OR OFFSHORE WATERS AND TROUGH

ALONG THE CA COAST. AN ASCAT PASS FROM AROUND 0547Z INDICATED A

COUPLE AREA OF 25 TO 30 KT WINDS OVER THE SRN OREGON AND NRN CA

COASTAL WATERS AND EXTENDING INTO THE FAR E PORTION OF N CA

OFFSHORE WATERS. 



THE 00Z MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT DURING THE

ENTIRE FCST PERIOD. THE MAIN FOCUS CONTINUES TO BE DURING THE

SHORT TERM PERIOD ROUGHLY FROM LATER THIS EVENING THROUGH WED

NIGHT AS LOW PRES STRENGTHENS OVER N CA AT THE SAME TIME HIGH PRES

ALSO STRENGTHENS W OF THE AREA. THIS WILL LEAD TO A PROLONGED GALE

EVENT OVER THE N CA COASTAL/OFFSHORE WATERS AS WELL AS THE FAR SRN

OREGON WATERS. EXPECT GALES INITIALLY OVER THE N CA COASTAL WATERS

LATER IN THE AFTERNOON THROUGH TONIGHT...THEN EXPANDING W INTO

OFFSHORE ZONES TUE. CONSIDERING THE VERY GOOD MODEL

AGREEMENT...CONFDC REMAINS HIGH WITH THIS EVENT. WILL CONTINUE TO

POPULATE WIND GRIDS WITH THE GFS 10M WINDS FOR THE MOST

PART...HOWEVER WILL USE A 50/50 BLEND OF 10M/30M FROM TUE MORNING

THROUGH WED NIGHT AS BELIEVE COVERAGE WILL BE MORE THAN INDICATED

BY 10M WINDS. LOOKING AHEAD TO THU AND BEYOND...THE LOW OVER N CA

WILL WEAKEN AS HIGH PRES W OF AREA ALSO WEAKENS WITH WINDS

DROPPING BELOW GALE. 



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

CONTINUED TO MATCH UP WELL WITH MODEL FCST VALUES. THE MWW3 LOOKS

GOOD OVERALL...HOWEVER SIMILAR TO PREVIOUS PACKAGE WILL USE ECMWF

WAM TUE AFTERNOON AND NIGHT AS IT BRINGS SEAS UP FASTER OVER GALE

AREAS COMPARED TO MWW3 WHICH SEEMS REASONABLE.



.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.

.PZZ900...OUTER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...

     GALE POSSIBLE WED NIGHT.

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

     GALE TUE NIGHT.

     GALE POSSIBLE WED INTO WED NIGHT. 



.PZ6 CALIFORNIA WATERS...

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

     GALE TUE NIGHT.

     GALE POSSIBLE WED INTO WED NIGHT. 



$$



.FORECASTER REINHART/KOSIER. OCEAN PREDICTION CENTER.

