

176 

AGPN40 KWNM 240314

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

814 PM PDT TUE AUG 23 2016



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

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



ONLY MINOR TWEAKS TO ONGOING GRIDS TO BETTER MATCH COASTAL OFFICE 

GRIDS...BUT STRESS THESE ARE VERY MINOR. IN REALITY GRID EDITS

WILL NOT AFFECT OVERALL ONGOING GBRIDS THAT ARE BASED ON THE 23/12Z

GFS. NO WIND WARNING HEADLINES WILL BE NEEDED THROUGH SUN NIGHT.

BRIEF SYNOPSIS FOLLOWS.



SIMPLE AND STRAIGHT FORWARD FORECAST IN STORE FOR THE ENTIRE

PERIOD. HIGH PRES W AND NW OF THE NRN WATERS WILL REMAIN NEARLY

STNRY INTO WED...SLOWLY DRIFT SW WHILE STRENGTHENING INTO

FRI...THEN PARK ITSELF ALONG 150W THRU THE WEEKEND. LOW PRES TROFS

ALONG THE CA COAST WILL REMAIN STNRY TONIGHT...BEFORE EXPANDING N

ACROSS THE OR/WA COASTS WED AND WED NIGHT. THE TROF WILL SLOWLY

DRIFT W AND OFFSHORE THU INTO FRI NIGHT...WITH A WEAK SURFACE LOW

FORMING IN THE NRN CA WATERS SAT THRU SUN NIGHT. MODELS SUGGEST AN

UPPER TROF CRESTING THE BLOCKING RIDGE SAT...DIGGING TOWARDS THE

PAC NW SUN AND SUN NIGHT. SURFACE REFLECTION AMONG GUIDANCE IS A

VERY WEAK PASSING TROF AND CIRCULATION WITH WINDS GENERALLY 15 KT

OR LESS. 



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PREVIOUS DISCUSSION...



THE 18Z SFC ANALYSIS INDICATED HIGH PRES CENTERED NEAR 48N135W

WITH RIDGE EXTENDING N ALONG SE COAST OF ALASKA AND SE ACROSS W

PORTION OF CA OFFSHORE WATERS. AN ASCAT PASS FROM 1752Z INDICATED

SEVERAL SMALL AREAS OF 25 KT OVER THE N CA OFFSHORE WATERS...AS

WELL AS THE SRN OREGON COASTAL WATERS. OTHERWISE...WINDS WERE 20

KT OR LESS. 



THE 12Z MODELS REMAIN IN VERY GOOD AGREEMENT DURING THE FCST

PERIOD WITH ONLY SUBTLE DIFFERENCES NOTED WITH THE SFC PRES

PATTERN. THE HIGH PRES MENTIONED ABOVE WILL MOVE N TONIGHT INTO

WED MORNING WHILE STRENGTHENING...THEN MOVE W THROUGH THE END OF

THE WEED AND INTO SAT WHILE CONTINUING TO STRENGTHEN SLIGHTLY

BEFORE WEAKENING LATE FRI. MEANWHILE TROUGH ALONG THE CA COAST

WILL EXPAND N ACROSS THE OREGON/WASHINGTON COASTS THROUGH EARLY

FRI BEFORE WEAKENING. GRADIENTS WILL BE SUCH THAT WINDS WILL

REMAIN BELOW WARNING CRITERIA THROUGH THE PERIOD...WITH THE

STRONGEST WINDS LIKELY TOPPING OUT NEAR 30 KT LATE FRI OVER THE

INNER PORTION OF WA WATERS. OTHERWISE...EXPECT 20 TO 25 KT WINDS

OVER THE WA/OR WATERS ESPECIALLY THE OUTER WATERS WITH WINDS OVER

THE CA WATERS MOSTLY 20 KT OR LESS. 



.SEAS...THE 18Z SEA STATE ANALYSIS INDICATED THAT OBSERVED SEAS

COTNINUE TO MATCH UP WELL WITH THE MWW3. WILL POPULATE WAVE GRIDS

USING THE MWW3 THROUGH THE PERIOD AS THERE ARE NO MAJOR

DIFFERENCES COMPARED TO THE ECMWF WAM. 



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

     NONE.



$$



.FORECASTER COLLINS/KOSIER. OCEAN PREDICTION CENTER.

