marine weather discussion for N Pacific Ocean
NWS ocean prediction center Washington DC
730 PM PDT Thu 18 Mar 2010

00z NCEP prelim surface analysis shows high pres ridging across
the offshore waters while low pres trough continues along the
Pacific coastline. 00z ship/buoy obs show 15-20 kt winds in the
pz5 waters...with a ship report of 30 kt winds in the coastal
waters just E of the se or offshore zone. Strongest winds were
across the srn CA waters with generally 15-25 kt winds...though
a ship did report 30 kt winds.

Per 00z obs and latest model guidance will drop gale warnings
from nrn/central CA waters with this forecast package. Otherwise
no other major changes will be made to the ongoing package. Low
pres moves through over the weekend impacting mainly the pz5
waters...high builds in to start the week...then another low
pres trough strengthens along CA coast heading into Tue allowing
for increased NW flow mainly across central/srn CA waters.
Frontal boundary also approaches pz5 waters by late Tue.

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Prev discussion

Over the NE pac continue to be concern about the interaction of
the prevailing ridge axis currently near 133w along with a mid
lat trough W 140w as both of these features move E through the
weekend. This trough assocd with a cpl strong shrtwaves driving
ENE. In the short term going with a general blend of the mdls...
but by late Sat into sun the GFS mdl more progressive with
trough and assocd stg short wave moving into SW can. Looking at
the can glbl/UKMET/ECMWF mdls and the ensemble means going with
a blend of the ECMWF and GFS mdls. This net impact of this blend
will weaken trough and assocd shrtwave but keeping it farther
west than a pure GFS track.

At the sfc...18z analysis has a prevailing ridge axis from the
WA ofshr SW through 42n133w to 31n135w as a weakening low pres
trough noted near the calif coast. This features with the assocd
pres gradient has prevailed but latest runs of the nam12 and
ruc2 over the ofshr wtrs has been showing a weakening trend.
Therefore for the early hours tngt will briefly mentioned gales
ern ptn of the nrn calif ofshr and the NE part of the cntrl
calif ofshr. Then given the blend of the GFS and ECMWF mdls with
dcrs winds.

The next main event will be a low pres cntr assocd first with a
wrmfnt moving into the or/WA ofhrs then followed by a weak cold
front...believe the stgst gradient will be W of the WA/OR ofshr
as the low moves NE into SW can...therefore will keep winds
below gale force.

By Mon into Tue have a weakening cold front moving into the
ofshr wtrs Mon as high pres prevails by Tue. Will go with the
blend noted above.

For the wave mdls...a blend of the mdls.

.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...none
.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 Holley/mcrandal. Ocean forecast branch.

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