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

                   
                     
381 
AGPN40 KWNM 140225
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN 
NWS OCEAN PREDICTION CENTER WASHINGTON DC
625 PM PST MON 13 FEB 2012 

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

IN THE STRONG NNWLY GRADIENT ALONG THE CA COAST GALE FORCE WINDS 
ARE PRESENT BTWN PT CONCEP AND CP MENDOCINA PRETTY MUCH AS 
PREVLY EXPECTED. MAX SEAS OVER THESE WTRS ARE UP TO 18-21 FT 
WHICH ARE SIGLY HIGHER THAN FCST BY THE 18Z WAVEWATCH III AND 
CLOSER TO THE HIGHER SEAS FCST BY THE 12Z ECMWF WAM.

OVER THE SHORT TERM...THE LATEST MDLS RMN IN GOOD AGRMT THAT THE 
NNWLY GRADIENT WL WEAKEN TO SUBGALE FORCE BY TUE MORNING. THEN 
LATER TUE THE FOCUS SHIFTS FURTHER N WHR THE MDLS GNRLY AGREE 
THAT IN REPONSE TO A CLOSED UPR LOW PASSING SE INTO THE PAC NW 
COAST AN ASCD WKNG SFC LOW WL TRACK SE ACRS THE PZ5 WTRS. VS ITS 
PREV 12Z RUN...THE 18Z GFS FCSTS A SMWHT WEAKER SFC LOW. BUT THE 
18Z GEFS INDICATES THAT THE 18Z GFS IS TOO WEAK. THEREFORE WL 
INSTEAD FAVOR A BLENDED 12Z GFS/UKMET/ECMWF SOLUTION FOR THIS 
SYSTEM. SO SINCE THESE MDLS WERE PREVLY PREVLY FAVORED DO NOT 
PLAN ON MAKING ANY SIG CHNGS TO THE PREVLY FCSTD ASCD GALE WRNGS 
OR ASCD CONDS.

THEN LATE IN THE SHORT TERM...LATE WED/WED NITE...AGAIN VS ITS 
PREV 12Z RUN THE 18Z GFS FCSTS A WEAKER SFC LOW TO PASS NW OF    
 THE PZ5 WTRS. AGAIN THE 18Z GEFS INDICATES THAT THE 18Z GFS IS 
TOO WEAK. THEREFORE PLAN ON USING A BLENDED 12Z GFS/ECMWF 
SOLUTION FOR THIS SYSTEM. PER THIS BLEND IT LOOKS CLOSE AS TO 
WHETHER GALES WL DVLP ACRS THE OUTER CP FLATTERY TO CP LOOKOUT 
WTRS WED NITE. BUT AS NOTED BELOW DUE TO LOW LVL STABILITY FOR 
NOW WL HOLD OFF ON FCSTG ANY GALE WRNGS AND WL SEE LATER WHAT 
THE 00Z MDLS SHOW. SO NO MAJOR CHNGS ARE PLANNED TO THE PREV PZ5 
FCST RGRDG THIS SYSTEM.

IN THE LONG RANGE...THE MOST SIG WX FEATURE IS A NRN STREAM SFC 
LOW FCST TO IMPACT THE NRN WTRS LATE FRI/SAT. THE 18Z GFS FCSTS 
A WEAKER SFC LOW THAN ITS PREV 12Z RUN...WHICH IS SPRTD BY THE 
18Z GEFS...BUT STIL FCSTS SM STORM FORCE ASCD BL WINDS ACRS THE 
PZ5 WTRS FRI NITE INTO SAT. FOR NOW WITH AT BEST A MODERATE 
LEVEL OF CONFIDENCE...WL USE A BLENDED 12Z/18Z GFS AND 12Z 
UKMET/ECMWF SOLUTION FOR THIS SYSTEM AND AS WAS DONE PREVLY WL 
HOLD OFF ON FCSTG ANY PSBL STORM WRNGS.



-----------------------------------------------------------------
PREVIOUS DISCUSSION...

THE 18Z OPC SFC ANALYSIS INDICATED LOW PRES OVER THE OREGON 
COASTAL WATERS...WITH A COLD FRONT TRAILING SW EXTENDING ACROSS 
THE CENTRAL CA WATERS. AN EARLIER OSCAT PASS FROM AROUND 0830Z 
INDICATED AREA OF GALES OVER THE OREGON AND N CA OFFSHORE AND 
COASTAL WATERS. THIS WAS EMBEDDED IN A LARGER AREA OF 20 TO 30 
KT WINDS COVERING ALL OF THE AREA N OF THE S CA WATERS. 

THE 12Z MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH MOST OF 
THE PERIOD ROUGHLY FROM CURRENT TIME THROUGH ABOUT 12Z FRI. WILL 
MAINTAIN THE GALES FOR THE CENTRAL CA WATERS TONIGHT AS STRONG 
CAA CONTINUES TO MOVE S WITH TIGHT PRES GRADIENT PERSISTING. 
WILL ALLOW THE GALES FOR THE OR AND N CA WATERS TO EXPIRE AS 
SCHEDULED. ANOTHER LOW IS FCST TO MOVE ACROSS THE WA WATERS 
TONIGHT WHICH WILL PRODUCE A PERIOD OF GALES. ALL OF THE MODELS 
NOW SEEM TO BE ON THE SAME PAGE WITH THE TRACK AND 
INTENSITY...SO WILL RAISE CONFDC LVL TO HIGH. HIGH PRES WILL 
THEN BUILD ACROSS AREA LATE TUE NIGHT INTO WED. ANOTHER FRONT 
WILL MOVE THROUGH THE WA/OR/N CA WATERS WED NIGHT INTO EARLY 
THU. THE MODELS DIFFER SOMEWHAT WITH THE INTENSITY OF THE LOW 
WHICH PASSES NW OF THE PZ5 WATERS...HOWEVER THEY ARE ALL SIMILAR 
WITH THE GRADIENT. THE GFS DOES INDICATE A BRIEF PERIOD OF GALES 
WED NIGHT OVER THE FAR NW WA WATERS...HOWEVER STABILITY PROGS 
KEEP WINDS BELOW GALE SO WILL HAVE WINDS MAXING OUT AT 30 KT. 
LOOKING FURTHER AHEAD TO FRI AND SAT...THE MODELS HAVE COME INTO 
SLIGHTLY BETTER AGREEMENT THAN THE PAST FEW DAYS...BUT STILL 
DIFFER ON THE EXACT TRACK AND INTENSITY OF LOW. THE GFS SEEMS 
LIKE A DECENT COMPROMISE BETWEEN THE FURTHER N TRACK OF THE 
ECMWF AND THE FURTHER S UKMET TRACK. WILL NOT INDICATE STORM 
FORCE WINDS OVER THE OREGON WATERS HOWEVER AS THE GFS INDICATES 
AND KEEP THE STRONGEST WINDS AT 40 KT. 

SEAS...THE 12Z MULTI-GRID WW3 APPEARED TO BE INITIALIZED WELL 
WITH OBSERVED SEAS MATCHING UP WELL WITH THE FCST VALUES. WILL 
ALSO GO CLOSE TO ITS VALUES THROUGH THE PERIOD SINCE WILL BE 
GOING CLOSE TO THE GFS. THE EXCEPTION WILL BE LATE FRI AND SAT 
WILL TRIM A FEW FT OFF THE WW3 SINCE WILL NOT BE GOING QUITE AS 
STRONG AS THE GFS WINDS. 

EXTRATROPICAL STORM SURGE GUIDANCE...N/A. 

.WARNINGS/FORECAST CONFIDENCE...PRELIMINARY. ANY CHANGES WILL BE 
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: 

.PZ5 WASHINGTON/OREGON WATERS... 
.CAPE FLATTERY TO CAPE LOOKOUT...GALE OVERNIGHT INTO TUE...HIGH 
CONFDC. GALE FRI INTO SAT...LOW CONFDC.
.CAPE LOOKOUT TO POINT ST GEORGE...GALE FRI INTO SAT...LOW 
CONFDC.

.PZ6 CALIFORNIA WATERS... 
.PT ST GEORGE TO PT ARENA...GALE OVERNIGHT...HIGH CONFDC. GALE 
FRI INTO SAT...LOW CONFDC. 
.PT ARENA TO PT CONCEPTION...GALE OVERNIGHT INTO TUE...HIGH 
CONFDC. 
.PT CONCEPTION TO GUADALUPE ISLAND...NONE. 

.FORECASTER VUKITS/KOSIER. OCEAN FORECAST BRANCH.