

347 

AGPN40 KWNM 211527

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

827 AM PDT SUN AUG 21 2016



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

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



AT 12Z A COLD FRONT WAS OVER THE NRN WA WATERS W/A HIGH PRES RIDGE

OVER THE REST OF THE OPC OFFSHORE WATERS. W/00Z GUIDANCE IN GOOD

AGREEMENT SEE NO REASON TO MAKE CHANGES TO THE ONGOING FORECAST

IN THIS INTERMEDIATE UPDATE.



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PREVIOUS DISCUSSION...



THE ASCAT PASSES FROM 04-06Z INDICATES MAINLY WINDS 20 KT OR LESS

ACROSS MUCH OF THE OFFSHORE WATERS WITH THE MAX WINDS 25 KT

OCCURRINGOVER NERN WA WATERS. THE OVERALL WEATHER PATTERN HAS

REMAINED VERY STABLE THE PAST SEVERAL DAYS WITH LITTLE CHANGE IN

THE FCST. THE 00Z GLOBAL MODELS ARE ALL IN VERY GOOD AGREEMENT

THROUGHOUT THE UPCOMING WEEK...WITH ONLY SMALL DIFFERENCES LATER

IN THE PERIOD...MAINLY DUE TO THE POSITION OF THE STRONGEST PRES

GRADIENT BETWEEN HIGH PRES W OF THE AREA AND A LOW PRES TROUGH

ALONG THE PACIFIC CST. DURING THE FIRST COUPLE OF DAYS HIGH PRES

WILL BUILD TOWARDS THE WA/OR WATERS...WHILE A TROF AXIS EXTENDS

ALONG THE NRN CA AND SW OREGON CSTS. THE RESULTING PRES GRADIENT

WILL PRODUCE MAX WINDS OF 25 KT...WITH OCCASIONAL 30 KT POSS. THE

STRONGEST WINDS WILL OCCUR IN THE COASTAL WATERS AND ALONG THE

BORDER WITH THE INNER OFFSHORE WATERS IN THE GENERAL VCNTY OF

POINT ST. GEORGE. LIGHT WINDS WILL PREVAIL DURING THAT TIME ACROSS

THE CENTRAL AND SRN CA WATERS. DURING DAYS 3-5 HIGH PRES WILL

SHIFT WESTWARD AS THE LOW PRES TROF EXPANDS N ALONG THE WA/OR

CSTS. THIS WILL ALLOW WINDS TO INCREASE TO 20-30 KT THROUGHOUT

MUCH OF THE WA/OR AND NRN CA WATERS. WILL POP THE WIND GRIDS

USING THE 10M GFS THROUGHOUT THE PERIOD.



SEAS...BOTH THE WAM AND ENP INITIALIZED WELL ACROSS THE REGION.

LATEST OBS INDICATE SEAS OVR THE WATERS GENERALLY 5-9 FT. WILL

POP THE WAVE GRIDS USING A 50/50 BLEND OF THE WAM AND ENP DURING

THE ENTIRE FCST PERIOD.



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

     NONE.



$$



.FORECASTER HOLLEY/SHAW. OCEAN PREDICTION CENTER.

