

171 

AGPN40 KWNM 041538

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

838 AM PDT SUN SEP 4 2016



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

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



OPC FINAL 12Z SFC ANALYSIS SHOWS A MAIN SFC HIGH PRES CENTER WELL

W OF CA WTRS NEAR 39N152W WITH A RIDGE EXTENDING NE TOWARD THE PZ5

WTRS WHILE LOWER PRES PREVAILS INLAND OVER THE WRN U.S. WHICH

INCLUDES A TROF EXTENDING FM INTERIOR SRN CA NW TOWARD NRN CA

COAST. EARLIER HIGH RES ASCAT-B PASS FM 05Z WAS A GOOD MATCH WITH

WIND GRIDS NEAR THAT TIME BASED ON 00Z GFS 10M WINDS. A SHIP

REPORTING N 28 KT AT 12Z NR 39N125W AND 35 KT 6 HR EARLIER CLOSER

TO PT REYES WAS SLIGHTLY HIGHER THAN ASCAT AND GRIDDED WINDS. FOR

THE MORNING UPDATE THE NEWER 06Z GFS IS SIMILAR TO 00Z RUN AND

OTHER GLOBAL GUIDANCE AND 06Z NAM AND MDLS REMAIN IN GOOD OVERALL

AGRMT THRU THE PERIOD. THE HIGHER GFS 30M WINDS LOOK A BIT

OVERDONE AT TIMES RELATIVE TO 00Z ECMWF/UKMET AND 00Z CMC GLOBAL

MDL IS OVERDONE WITH N TO NW FLOW ESPCLY MON NIGHT THRU THU NIGHT.

HENCE WILL CONTINUE TO GO WITH MORE REPRESENTATIVE 10M GFS WINDS

THRU THE PERIOD. NO CHANGES APPEAR NEEDED AT THIS TIME.



SEAS...CURRENT WAVE GRIDS ARE BASED ON 00Z ENP NWW3 WHICH APPEAR

INITIALIZED WELL COMPARED TO 12Z SFC OBS AND ALTIMETER DATA. PLAN

TO STAY WITH CURRENT WAVE GRIDS WHICH SHOW ONLY MINOR DIFFERENCES

WITH 00Z ECMWF WAM THRU THE PERIOD.

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

PREVIOUS DISCUSSION...



SUMMARY...00Z NCEP SFC ANALYSIS SHOWS AN INLAND LOW PRES TROF

OVER CALIFORNIA...WITH A HI PRES RIDGE BUILDING E AND NE TOWARDS

THE WEST COAST OF CONUS. LATEST AVAILABLE ASCAT HI-RES PASSES FROM

EARLIER TONITE INDICATE N TO NW WINDS OF 25 TO 30 KT IN THE SRN

OREGON/NRN CALIFORNIA COASTAL WTRS...AND ALSO OVER THE ADJACENT

INNER ZONES OF THE NRN PZ6 WTRS.



MAIN WEATHER FEATURES...RELATIVELY WEAK LOWS ARE EXPECTED TO

SLIDE OVER THE TOP OF THE EPAC RIDGE AND PASS SE ACROSS THE PZ5

AREA LATE MON INTO TUE...THEN AGAIN WED INTO THU. OTHERWISE THE

CALIFORNIA TROF AND THE EPAC RIDGE WILL PREVAIL THRU THE FCST

PERIOD AND PRODUCE ROBUST N TO NW FLOW OVER THE NRN AND CENTRAL

CALIFORNIA OFSHR/COASTAL WTRS.



MODELS...THE 00Z MED RNG MDLS ARE IN VERY GOOD OVERALL AGREEMENT

ACROSS THE OFSHR/COASTL WTRS THRU THE FCST PERIOD...EXCEPT THE 00Z 

CANADIAN GEM LOOKS OVERDONE WITH THE N TO NW FLOW FOR MON NITE

INTO THU NITE. 00Z GFS 30M SOLN LOOKS A BIT OVERDONE AT TIMES

WITH THE STRENGTH OF N TO NW FLOW SO WILL USE THE REPRESENTATIVE

00Z GFS 10M SOLN FOR THE WIND GRIDS OVER THE ENTIRE FCST PERIOD. 

AM NOT PLANNING TO MAKE ANY SIGNIF CHANGES TO THE CURRENT FCST

TREND.



SEAS...THE 00Z ENP WAVEWATCH III MDL AND THE 00Z ECMWF BOTH LOOK

REASONABLE WITH THE SEA HTS THRU THU NITE...AND ARE ALSO IN VERY

GOOD OVERALL AGREEMNT. WILL USE THE 00Z ENP WAVEWATCH III MDL FOR

THE WAVE HT GRIDS THRU THE ENTIRE FCST PERIOD.



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



.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

     NONE.



$$



.FORECASTER BANCROFT/SCOVIL. OCEAN PREDICTION CENTER.

