000
AGPN40 KWNM 021406
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
706 AM PDT TUE SEP 2 2014

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

AS THE LOW PRES TROF INLAND CALIFORNIA CONTS TO EVER SO SLOWLY
STRENGTHEN THE NNWLY GRADIENT OFSHR ACRS THE NRN PZ6 AND SE MOST
PZ5 WTRS CONTS TO FOLLOW SUIT WITH MAX ASCD WINDS NOW LIKELY IN
THE 25-30 KT RANGE. FURTHER N A WEAK COLD FRONT IS NOW MOVG SE
INTO THE NW MOST PZ5 WTRS BUT ASCD WINDS HV YET TO INCRS. MAX SEAS
THRUT THE WTRS ARE IN THE NRN PZ6 WTRS WITH THE NNWLY GRADIENT AND
ARE IN THE 8-10 FT RANGE WHICH OVERALL ARE BEING HANDLED FINE BY
THE 00Z/06Z WAVEWATCH III AND 00Z ECMWF WAM MDLS AT THE MOMENT.

OVER THE SHORT TERM...THE NEW 06Z MDLS REMAIN CONSISTENT VS THEIR
PREV RESPECTIVE RUNS. FOR THE PZ5 WTRS IN THE WAKE OF THE PASSING
COLD FRONT...MAINLY PER THE 00Z/06Z GFS 30M BL WINDS...WL CONT
WITH THE PREVLY FCSTD MARGINAL GALE WRNG FOR THE NE MOST PZ5 WTRS
FOR EARLY TONITE. FURTHER S AS THE INLAND TROF CONTS TO SLOWLY
STRENTHEN AND STRONGER HIGH PRES BUILDS IN FROM THE NW BEHIND THE
NRN COLD FROPA THE LATEST MDLS ALL FCST THE NNWLY GRADIENT TO
STRENGTHEN WITH WINDS REACHING GALE FORCE BY LATE TODAY/TONITE...
THEN PERSISTING INTO EARLY THU. THE LATEST GFS/NAM/GEM CONT TO
FCST THE STRONGEST GRADIENT WHL THE NAVGEM/UKMET/ECMWF FCST
SLIGHTLY WEAKER GRADIENTS. BLV A BLEND OF THE 00Z/06Z GFS 30M AND
00Z ECMWF BL WINDS WULD BE A RSNBL COMPROMISE FOR THIS GRADIENT.
BUT FOR NOW DO NOT WANT TO FLIP-FLOP VS THE PREV FCST PACKAGE SO
WL NOT REPOPULATE THE PREVLY USED 00Z GFS 30M BL WINDS THRU THE
SHORT TERM...BUT WL MAKE SM MINOR EDITS IN DEFERENCE TO THE 00Z
UKMET/ECMWF WHICH WL RESULT IN SM SMALL CHANGES.

IN THE LONG RANGE...BY LATE THU INTO SAT THE LATEST GLOBAL MDLS
REMAIN IN RSNBLY GOOD AGRMT THAT THE INLAND TROF WL BEGIN TO
SLOWLY WEAKEN AS IT EXPANDS SLOWLY NWD UP THE PAC NW COAST AND THE
AREA OF HIGH PRES W OF THE PZ5 WTRS WL ALSO WEAKEN. AS A RESULT
THE MDLS TO VARYING DEGREES ALL FCST THE NNWLY GRADIENT TO GRADLY
WEAKEN. AGAIN MY INCLINATION WULD BE TO USE A 00Z/06Z GFS 30M AND
00Z ECMWF BLEND FOR THIS GRADIENT...BUT SINCE THE DIFFS BTWN THEIR
GRADIENTS NARROW (AND THE 00Z/06Z GFS VS THEIR RUNS OF YESTERDAY
ARE SLOWER WITH THE NEXT APRCHG FRONT SAT/SAT NITE WHICH IS MR IN
LINE WITH THE ECMWF)...FOW NOW WL CONT TO USE THE PREVLY
POPULATED 00Z GFS 30M BL WINDS THRUT THE LONG RANGE. SO NO SIG
LONG RANGE CHNGS ARE PLANNED FOR THE NEXT OFSHR FCST PACKAGE.


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

THE MAIN CONCERN OVR THE NEXT FEW DAYS WILL BE THE GALES EXPECTED
TO DEVELOP BY LTR TDA OVR NE PZ5 OFF WTRS AND OFF THE NOCAL
COAST...AND THEN OFF THE SW OREG COAST TNGT. A COLD FRONT WILL
SWEEP SE OVR PZ5 WTRS TDA WITH STRONG UPR LVL SUPPORT...ALLOWING
GALES TO DVLP OVR NE WASH OFF WTRS OR ZONE 800 BY LTR TDA. THE
PRES GRAD BETWEEN A COASTAL LOW PRES TROF AND HIGH PRES BUILDING
W AND NW OF THE CALIF WTRS WILL ALSO ALLOW GALES TO FORM OVR THE
FAR ERN NOCAL WTRS...OR ZONE 820 BY LTR TDA AND TNGT...WITH THE
GALES SPREADING N INTO S OREG OFF WTRS...OR ZONE 815 FOR TNGT.
THE GALES WILL END OVR THE NE WASH OFF WTRS LTR TNGT...AND
PERSIST OVR NOCAL AND SE OREG OFF WTRS WED AND WED NGT...FINALLY
ENDING THU. WINDS MAY REACH 40 KT FOR A TIME OVR FAR ERN NOCAL
OFF WTRS WED INTO WED NGT WITH GUSTS POTENTIALLY REACHING STORM
FORCE PER THE GUSTS INDICATED BY THE GFS AND 4NM NAM MDL GUID. WE
WILL BUMP WINDS TO 30-40 KTS FOR TIME OVR THE NOCAL WTRS WED INTO
WED NGT AS A RESULT. OTW...THE PRES GRAD IS FCST TO SLOWLY WEAKEN
THU INTO THE WKND AS THE HIGH TO THE NW OF THE WTRS DRIFTS S AND
WEAKENS...ALONG WITH A WEAKENING COASTAL LOW PRES TROF. THE NEXT
COLD FRONT WILL APPROACH PZ5 WTRS SUN.

MODELS...THE 00Z MDLS REMAIN IN EXCELLENT AGREEMENT OVR THE OFF
WTRS FOR THE NEXT SEVERAL DAYS. WE PREFER THE HIGHER 30M GFS
WINDS FOR THE FCST RIGHT INTO THE WKND AS A STRONG UPR LVL VORT
MAX SWINGS SE OVR PZ5 WTRS TDA FOLLOWED BY AN UPR LVL RIDGE
BUILDING TO THE W OF THE PZ5 WTRS WED THRU THE END OF THE WK. WE
WILL TRANSITION TO A 50-50 BLEND OF THE GFS/ECMWF WINDS BY SUN
INTO EARLY NEXT WK. OVRALL...CONFDC IN THE FCST IS NR TO ABV
AVERAGE.

.SEAS...INITIALLY BOTH THE ENP WV WATCH III AND ECMWF WAM WV MDLS
ARE RUNNING MOSTLY WITHIN A FT OR TWO OF THE OBS NOTED NR AND OVR
THE OFF WTRS. THE 00Z ECMWF WAM APPEARS TO BUILD SEAS A LITTLE
FASTER THAN THE WV WATCH IN AND NR THE GALE AREAS BY TNGT THRU
WED NGT. IT ALSO BUILDS SEAS A LITTLE HIGHER AND OVR A SOMEWHAT
WIDER AREA THAT THE WW3 MDL. WE PREFER THIS IDEA SO WE WILL BE
USING THE 00Z ECMWF WAM FOR WV HTS OVR THE OFF WTRS FOR THE NEXT
FEW DAYS...INTO SAT NGT. WE WILL ALSO TWEAK GRIDS CLOSER TO THE
COASTAL WTRS TO FIT THE LATEST CWF. OTW...BY SUN WE WILL BLEND
THE WV WATCH III WITH THE ECMWF WAM.

.EXTRATROPICAL STORM SURGE GUIDANCE...NA


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ800...INNER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
GALE TONIGHT.
.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
GALE TONIGHT INTO WED NIGHT.
GALE POSSIBLE THU.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
GALE TONIGHT INTO WED NIGHT.
GALE POSSIBLE THU.

$$

.FORECASTER VUKITS/MILLS. OCEAN PREDICTION CENTER.