

042 

AGPN40 KWNM 031453

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

753 AM PDT WED AUG 3 2016



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

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



A FAMILIAR PATTERN PERSISTS OVER THE FCST WTRS THIS MORNING WITH

A 1038 MB HIGH CENTERED NEAR 44N147W AND A 1012 MB LOW ANALYZED

OVER NRN CA PER THE 12Z SFC ANALYSIS. THE RESULTING PRES GRADIENT

IS PRODUCING ENHANCED NLY FLOW OVER THE NRN CA/SRN OR WATERS. THE 

808Z RSCAT PASS CAPTURED 15-25 KT WINDS OVER THE SRN OR OFFSHORE

ZONES WITH 20-30 KT OVER THE NE CA WTRS...AND EVEN A SMALL POCKET

OF 30-35 KT WITHIN THE NRN CA COASTAL WTRS. A LATER PASS AROUND

0945Z SHOWED A BROAD SWATH OF 15-25 KT WINDS OVER THE CENTRAL CA

WATERS. THE MODELS CONTINUE TO INDICATE MARGINAL GALES ARE

POSSIBLE OVER THE FAR NE PORTION OF OUR INNER NRN CA OFFSHORE

ZONE LATER TODAY INTO TONIGHT. HAVE MAINTAINED THE GALE WARNING

FOR THIS ZONE BUT PUSHED BACK THE ONSET OF GALES UNTIL 00Z THU

BASED ON THE 06Z GFS/00Z ECMWF GUIDANCE. OTHERWISE...NO NOTABLE

CHANGES WITH THIS MORNING UPDATE.



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

PREVIOUS DISCUSSION...



A NRLY STNRY HIGH PRES AREA REMAINS CENTERED NEAR 45N 144W W OF

OREGON OFSHR WTRS PER THE 06Z SFC ANALYSIS. STRONG NLY FLOW

PERISTS BETWEEN A THERMAL OR INVERTED SFC TROF OVER INLAND CA AND

THE RIDGING FM THE HIGH EXTENDING INTO THE NRN WATERS...STRONGEST

OFF NRN CA AND SRN OREGON. 05Z HIGH RES ASCAT-A PASS INDICATED 30

TO 35 KT BETWEEN CAPE BLANCO AND PT ARENA WITH GALES CONFINED TO

CSTL WTRS...WHILE ADJ NRN CA ZONE PZZ820 SHOWED SOLID 25-30 KT.

WINDS DIMINISH TO 15 TO 20 KT NRN OREGON WTRS NWD AND TO THE

S...LIGHT OVR SRN CA WTRS CLOSER TO INVERTED TROF. 



LATEST 00Z MDLS REMAIN IN GOOD AGRMT WITH THIS SLOWLY EVOLVING

TYPICAL SUMMERTIME PATTERN OF PERSISTENT NLY FLOW BETWEEN THE EPAC

HIGH AND THE LOWER PRES INLAND. MDLS SHOW THE HIGH PRES DRIFTING W

AND STRENGTHENING THRU WED NIGHT WITH PRES GRADIENT TIGHTENING IN

RESPONSE TO A DEEPENING INLAND TROF OVR NRN/CENTRAL CA. GALES ARE

MOST LKLY IN NRN CA/SRN OREGON CSTL WTRS BUT HAVE BEST CHANCE TO

EXPAND INTO ADJ NRN CA INNER ZONE 820 WED INTO WED NIGHT. MDLS

THEN BRING ANOTHER MID/UPR LVL LOW SE FM GLF OF AK TO VANCOUVER

ISL LATE THU AND THU NIGHT AND INTO WA LATE FRI AND INTO WEEKEND 

WHICH WILL DEEPEN THE UPR TROF NR THE WEST COAST AND TEND TO WKN

THE RIDGE IN THE OFSHR WTRS. THIS WILL TEND TO RELAX THE GRADIENT

OVR THE OFSHR WTRS TO KEEP WINDS SUBGALE IN OFSHR WTRS AFTER WED

NIGHT. FOR THE NEW FCST GRIDS WILL POPULATE WITH THE

REPRESENTATIVE 00Z GFS 30M OR FIRST SIGMA LAYER WINDS FOR TODAY

AND TONIGHT WHEN GALES ARE MOST LKLY...AS THESE MORE CLOSELY MATCH

OBSVD CONDS. AFTER 12Z THU AND THRU THE RMNDR OF THE PERIOD WILL

USE A 50/50 BLEND OF GFS 10M AND 30M WINDS WHICH WILL YIELD GALES

AT TIMES CONFINED TO NRN CA/SRN OREGON CSTL WTRS.



.SEAS...WITH THE 00Z ECMWF WAM MATCHING UP BEST WITH OBS WILL

POPULATE WITH THAT GUIDANCE THRU WED NIGHT WHICH APPRS TO HAVE

BETTER HNDL ON MAX SEAS AND THEN SHIFT PREFERENCE TO A 50/50

BLEND OF THE 00Z NWW3/ECMWF WAM OUTPUT THU THROUGH SUN NIGHT WHEN

DIFFERENCES ARE SMALL. BOOSTED SEAS BY 10 PCT FOR FIRST TWO

PERIODS WITH GALES IN THE FCST.



.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 TONIGHT.



$$



.FORECASTER REINHART/BANCROFT. OCEAN PREDICTION CENTER.

