137 
AGPN40 KWNM 152130
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN 
NWS OCEAN PREDICTION CENTER WASHINGTON DC
130 PM PST WED 15 FEB 2012 

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

LTST VIS IMGRY ACRS EPAC SHOWS ROPE CLOUD FEATURE ACRS THE SRN 
CAL WTRS WHICH LINES UP WELL WITH 12Z BL MOISTURE CONVERGENCE 
AND THETA GRAD GUID. 18Z OPC/NCEP SFC MAP CONFIRMS THIS FEATURE 
AS A COLD FRONT...AND THE BOUNDARY IS XPCTD TO CONT MVG TO THE S 
TNGT. STG WINDS NOTED BEHIND THE FRONT...HOWEVER REG GUID CONTS 
TO KEEP WINDS BELOW GALE CRITERIA...AND IF ANY SFC WINDS WERE TO 
REACH OR ECLIPSE 34 KT WARNING LEVEL FEEL CONFIDENT THAT THIS 
WOULD BE CONFINED WITHIN THE COASTAL ZNS. BACK TO VIS SAT 
IMGRY...NEXT MAJOR SYSTEM TO AFFECT THE NRN ZNS CLEARLY SEEN ABT 
300 NM TO THE W OF THE OUTER PORTIONS OF THE WASH/OREG WTRS. 
STILL EXPECT A TRIPLE POINT LOW TO DEVELOP ALONG THIS FRONT AND 
LIFT NE TO THE QUEEN CHARLOTTES BY LATER TNGT...AND AS THE FRONT 
MOVES ACRS THE AREA XPCT WINDS TO INCR TO GALE CRITERIA OVER THE 
WASH WTRS. 

FOR THE AFTN FORECAST PACKAGE WILL USE A BLENDED ECMWF/GFS GUID 
FOR BOTH THE TIMING AND INTENSITY OF A STRONG SHORTWAVE TROF AND 
QUICKLY DEVELOPING...AND RATHER INTENSE SFC LOPRES FRI NIGHT 
INTO SAT ACRS THE PAC NW. BOTH THE 12Z GFS AND ECWMF HAVE 
TRENDED SLOWER AND FARTHER N THAN THEIR RESPECTIVE 06Z AND 00Z 
RUNS...SO FEEL A COMPROMISE IS A GOOD SOLUTION WHICH MATCHES 
WELL WITH ENSEMBLE MEANS. FORECAST SFC WINDS ARE ALSO SOMEWHAT 
PROBLEMATIC FOR THIS LOW PRES. GFS/ECWMF GUID SUGGEST GOOD UPPER 
SUPPORT AND STRONG JET STREAK/STRUCTURE ACCOMPANYING THE 
LOPRES...HOWEVER WITH SINCE SOME ASPECTS OF THE FCST ARE STILL 
UNCERTAIN...WILL ONLY FCST STRONG GALES TO 45 KT FOR NOW. BOTH 
MODELS MENTIONED ABOVE INDC WINDS COULD REACH STORM FORCE FOR 
THE WASH WTRS...HOWEVER WILL AWAIT FUTURE MODEL 
CYCLES/CONSISTENCY TO SEE IF UPGRADE IN WARNING CATEGORY IS 
NEEDED. FARTHER TO THE S AND LATER IN FCST PD...ALSO FOR 
SAT...12Z GFS/GEM INDC WINDS INCRSNG TO GALE FRC ACROSS THE SRN 
CAL WTRS AS PRES GRADIENT INCRS B/W COASTAL TROF AND BUILDING 
HIPRES BEHIND A PASSING CDFNT. WITH OTHER 12Z SOLUTIONS ECMWF 
AND UKMET KEEPING WINDS SUB GALE...AND SINCE GENERALLY TRENDING 
FCST TOWARDS ECMWF ANYWAYS...WILL CONT WITH WINDS TO ONLY 30 KT 
FOR AFTN PKG. 

SEAS...BASED ON CURRENT OBS THE 12Z MWW3 SEEMS TO BE ABT 1 TO 2 
FT ON THE HIGH SIDE OF SIG WAVE HEIGHTS. WILL MAKE DOWNWARD 
ADJUSTMENTS IN THE INITIAL PDS ACCORDINGLY. THEREAFTER SINCE 
FOLLOWING MORE OF A BLENDED SOLUTION WILL TREND WAVE HEIGHTS 
CLOSER TOWARDS ECMWF WAM GUID...HOWEVER WITH POTENT PAC NW LOW 
STILL EXPECT SIG WAVE HEIGHTS TO 32 FT (CURRENT 12Z MWW3 OUTPUT 
IS 37 FT MAX FOR 12Z SAT ACRS WASH WTRS).  

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 TNGT...MDT TO HI CONFDC. 
GALE FRI INTO SAT...MDT CONFDC. 
.CAPE LOOKOUT TO POINT ST GEORGE...GALE FRI NIGHT INTO SAT...MDT 
CONFDC. 

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

.FORECASTER COLLINS. OCEAN FORECAST BRANCH.