NOAA>NWS>NCEP>OPC>N Pacific Marine Discussion

                   
                     
989 
AGPN40 KWNM 272158 AAA
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN 
NWS OCEAN PREDICTION CENTER WASHINGTON DC
725 AM PDT THU 27 AUG 2009 

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT 
.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W. 

UPDATE:

06Z NAM/GFS AND 00Z ECMWF/GEM/UKMET SOLNS ARE IN GUD AGREEMNT 
THRU THE FCST PRD. THE 06Z GFS IS IN CLOSER AGREEMNT WITH THE 
00Z ECMWF THAN THE 00Z GFS IN THE GLF OF AK. AM PLANNING TO 
FAVOR THE 06Z GFS FOR THE OFSHR WTRS FCST PACKAGE THIS 
MRNG...WITH NO SIGNIF CHANGES PLANNED TO THE CURRENT FCST TREND.

SEAS...06Z WAVEWATCH III MDL APRS TO BE INITIALIZING WELL OVER 
THE OFSHR WTRS...AND LOOKS REASONABLE THRU THE FCST PRD...SO AM 
GOING TO FOLLOW THE WAVEWATCH III GUIDANCE FAIRLY CLOSELY.

PREV DISCUSSION:

MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGHOUT THE FORECAST 
PERIOD. WILL CONTINUE WARNINGS FOR THE W PORTION OF THE 
WASHINGTON WATERS FOR EARLY THU. AS DEEP LOW INVOF 49N143W ON 
THE 06Z SURFACE ANALYSIS RETROGRADES TWD THE GULF OF AK INTO 
FRI...ANY GALES BRUSHING THE W PORTIONS OF THE WASHINGTON WATERS 
WILL SHIFT W AND N OUT OF THE WATERS BY EARLY THU. HAVE 
DECREASED CONFDC TO LOW IN THIS PACKAGE HOWEVER...AS IT WILL BE 
A CLOSE CALL WHETHER GALES WILL TOUCH FAR W PORTION OF NRN PZ5 
ZONE OR REMAIN JUST TO THE W OF THE OFFSHORE WATERS. 

NEXT LOW DOWNSTREAM WILL REMAIN FAR ENOUGH N AND W OF THE WATERS 
AS IT TRACKS TWD THE GULF OF AK THAT THE ONLY EFFECTS ON THE PZ5 
WATERS WILL BE A WEAKENING FRONT REACHING THE REGION LATE SAT 
INTO SUN. THE 00Z GFS AND 00Z ECMWF SHOW THE PARENT LOW THEN 
TRACKING SE FROM THE GULF OF AK..REACHING A POSITION NW OF THE 
WATERS BY THE END OF THE PERIOD. THE GFS IS A BIT DEEPER AND W 
OF THE ECMWF WITH THIS LOW BY 12Z TUE. 

FURTHER S...A COASTAL TROUGH WILL DEVELOP ALONG THE CALIFORNIA 
COAST FRI AND PERSIST THROUGH SUN. GRADIENT IS NOT EXPECTED TO 
BE STRONG ENOUGH THE SUPPORT GALES OVER THE OFFSHORE WATERS...SO 
WILL KEEP WARNINGS AS IN THE PREVIOUS FORECAST. 

SEAS...THE WW3 LOOKED REASONABLE COMPARED TO THE 00Z SEA STATE 
ANALYSIS. SOUTHERLY SWELL FROM T.S. IGNACIO WILL AFFECT THE SRN 
WATERS THU BEFORE NW SWELL FROM THE DEEP GULF OF AK LOWS TAKES 
OVER. WILL GENERALLY FOLLOW THE WW3 OUTPUT. 

.WARNINGS/FORECAST CONFIDENCE...WARNINGS ARE PRELIMINARY AND ARE 
SUBJECT TO CHANGE. ANY CHANGES WILL BE COORDINATED THROUGH AWIPS 
12 PLANET CHAT OR BY TELEPHONE. 

.PZ5 WASHINGTON/OREGON WATERS... 
.CAPE FLATTERY TO CAPE LOOKOUT....GALE EARLY THU...LOW CONFDC. 
.CAPE LOOKOUT TO POINT ST GEORGE...NONE. 

.PZ6 CALIFORNIA WATERS... 
.PT ST GEORGE TO PT ARENA...NONE. 
.PT ARENA TO PT CONCEPTION...NONE. 
.PT CONCEPTION TO GUADALUPE ISLAND...NONE. 

.FORECASTER SCOVIL/BELL. OCEAN FORECAST BRANCH.