

386 

AGPN40 KWNM 060335

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

835 PM PDT FRI AUG 5 2016



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

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



STNRY 1035 MB HIGH PRES PERSISTS THIS EVENING AND PER 00Z SFC

ANALYSIS WAS LOCATED NEAR 45N147W. A SFC TROF WAS JUST N OF THE

WATERS AND EXTENDING NW FM VANCOUVER ISL AND WAS CAUSING A WIND

MAX W AND NW OF VANCOUVER ISL WHERE SHIPS WERE RPTG 30 KT W OF

QUEEN CHARLOTTE ISL. SFC TROF PREVAILS FM CENTRAL CA TO THE N CA

COAST. IN THE NLY FLOW BETWEEN RIDGE AND TROF...BASED ON 00Z SFC

REPORTS N TO NW WINDS 15-25 KT PREVAIL ACROSS THE CENTRAL AND NRN

PZ6 WTRS AND FAR SE PZ5 WTRS BETWEEN THESE FEATURES...AND AS

INDICATED BY EARLIER HIGH RES ASCAT PASSES PSBL HIGHER WINDS IN

ADK NRN CA AND SRN OREGON CATL WTRS. FOR THE EVENING UPDATE

ADJUSTED THE WIND GRIDS UPWARD 5 TO 10 PCT CLOSER TO A 50/50 BLEND

BETWEEN 12Z GFS 10M AND 30M WINDS BUT OTRW NO SIGNIFICANT CHANGES

ARE NECESSARY AS GFS 10M WINDS IN THE NEAR TERM APPEAR TO BE MOST

REPRESENTATIVE ATTM. AS EPAC RDG REBUILDS EARLY NEXT WEEK WHILE CA

TROF DEEPENS...THERE REMAINS MDT SPRT AMONG MDLS FOR AN AREA OF

GALES CENTERED ARND PT ARENA MOST LKLY ON TUE WHEN A GFS 10M/30M

BLEND SIMILAR TO START OF FCST LOOKS REPRESENTATIVE.



SEAS...FOR START OF FCST THE 12Z ECMWF WAM IS SLGTLY PREFERRED OVR

ENP WW3 BUT OTRW THE LATTER MDL LOOKS RSNBL FOR FCST FM LATER

TONIGHT AND AFTERWARDS.

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

PREVIOUS DISCUSSION...



THE 18Z NCEP SFC ANALYSIS SHOWS A 1035 MB HIGH NEAR 45N147W WITH N

TO NW FLOW PREVAILING ACROSS THE PZ5/6 WTRS THIS AFTN. AN ASCAT-B

PASS AT 1726Z CAPTURED 15-20 KT WINDS OVER THE SRN PZ6 WTRS...AND

A LATER ASCAT-A PASS FROM 1810Z REVEALED 15-20 KT WINDS OVER THE

OUTER PZ6 WTRS AS WELL. BASED ON THESE PASSES...THE 12Z GFS 10M

WINDS APPEAR TO HAVE INITIALIZED WELL AND ARE A GOOD CHOICE TO

START WITH TODAY.



THE 12Z GFS/ECMWF REMAIN IN VERY GOOD AGREEMENT THRU THE FCST

PERIOD. CURRENT WV IMAGERY OVER THE E PAC REVEALS A MID/UPR LOW

OVER VANCOUVER ISLAND...AS WELL AS A SHORTWAVE TROF APPROACHING

THE NRN CA WTRS FROM THE W. THE MODELS AGREE THESE FEATURES WILL 

WEAKEN THE OFFSHORE RIDGE AND RELAX THE PRES GRADIENT THRU THE

WEEKEND...DIMINISHING WIND SPEEDS TO 15-20 KT OVER THE CA WTRS

WITH EVEN WEAKER WINDS OVER THE INNER OR/WA WTRS. AS THE UPR LOW

MOVES INLAND OVER WA SUN NIGHT INTO MON...THE UPR RIDGE W OF THE

OFFSHORE WTRS STRENGTHENS...ALLOWING THE SFC HIGH TO MOVE SE WITH

A SFC RIDGE AXIS BUILDING ACROSS THE PZ5 WTRS BY MON NIGHT. THUS

WIND SPEEDS OVER THE NRN/CENTRAL CA WTRS WILL INCREASE MON INTO

TUE AS THE GRADIENT TIGHTENS YET AGAIN ALONG THE W COAST.



GALES REMAIN A THREAT ON TUE AS THE 12Z MODELS LED BY THE GFS 

STILL DEPICT 30-35 KT OVER THE NRN CA COASTAL AND POSSIBLY INNER

OFFSHORE WTRS. WITH BUILDING HIGH PRES OFFSHORE ON TUE MAKING ITS

CLOSEST APPROACH TO THE COAST...WILL CONTINUE TO USE A 30M/10M

GFS BLEND FOR TUE. THIS YIELDS A SMALL AREA OF GALES OVER INNER

PORTIONS OF PZZ820/825. OTHERWISE...THE 12Z GFS 10M WINDS WERE

THE PREFERRED MODEL CHOICE TODAY. WINDS DIMINISH FAIRLY QUICKLY

LATE TUE THRU WED AS HIGH PRES MOVES NW AND THE GRADIENT RELAXES.



.SEAS...USED THE 12Z ECMWF WAM THRU TONIGHT AS THIS MATCHED UP

WELL WITH THE LATEST OBS AND SEA STATE ANALYSIS. THEN TRANSITIONED

TO THE 12Z NWW3 SAT THRU WED NIGHT...WHICH OVERALL WAS FAIRLY

CONSISTENT WITH THE WAM BUT GENERATED HIGHER SEAS WITH THE GALES

ON TUE.



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



.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

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

     GALE POSSIBLE TUE.

.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...

     GALE POSSIBLE TUE.



$$



.FORECASTER BANCROFT/REINHART. OCEAN PREDICTION CENTER.

