marine weather discussion for N Pacific Ocean

NWS ocean prediction center Washington DC

630 PM PST Fri 20 Nov 2009

.Forecast discussion: major features/winds/seas/significant

.Weather for the North Pacific N of 30n and E of 150w.

00z NCEP prelim surface analysis shows high pres ridging over

most of the offshore waters...except the se central...srn CA

waters where a cold front is located. Available 00z ship/buoy

obs indicated winds have come down across the region as high

pres ridging has moved overhead.

18z GFS/NAM remain in good agreement with prior 12z global model

runs into Mon. So will not make any significant changes in the

near term and allow current warnings to remain in place for

gales in the pz5 waters Sat/Sat night and again Sun night into

Mon. Tue into Wed next frontal system approaches and while again

some timing differences arise risk remains for pre-frontal gales

so will continue with low confdc gales Wed in WA waters.

-----------------------------------------------------------------

Previous discussion...

The qkscat pass from 1325z indicated a small area of 35 kt winds

over the Washington waters...which were embedded in a larger

area of 20 to 30 kt winds over most of the pz5 waters. Over the

CA waters winds were mostly 10 to 15 kt...except over the

central CA waters ahead of front where winds ranged from 15 to

25 kt. The 18z opc sfc analysis indicates that the cold front

continues to advance se across the central CA waters and nearing

the N tip of S CA waters.

For the period tonight through Sat night...the models are in

decent agreement for the most part...though the 12z GFS is now

stronger with the low that is forcast to N Oregon and se WA

waters Sat evening. Also...the GFS is lower than any of the

other global models so will lean toward consensus of ECMWF...CMC

and UKMET. Even with the stonger low...the warnings will

essentially remain unchanged. The GFS does indicate a brief

period of gales for the N CA waters Sat night...but dont believe

this warrents adding gales and will continue to mention for the

WA/OR waters only. The next system approaces late sun and Mon.

The last few GFS runs have indicated onset of gales earlier...so

will add for the Sun night period for the Sun night period and

continue into Tue. Yet another system will appraoch late Tue and

move through the pz45 waters Wed. Will mention low confdc gales

for the WA waters Wed...mainly early.

The 18z sea state analysis indicated that seas over the offshore

and coastal waters were running about 2 to 4 ft higher than

indicated by the ww3. Over the remainder of the area E of

150w...the ww3 values matched up better with the observed

values. Will indicate seas a few ft lower than the model for

tonight...then plan to go close to the ww3 for the remainder of

the period.

.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 Sat into Sat night...MDT

confdc. Gale Sun night into Mon...low to MDT confdc. Gale Tue

into Wed...low confdc.

.Cape Lookout to point St George...Gale Sat into Sat night...MDT

confdc. Gale Sun night into Mon...low confdc.

.Pz6 California waters...

.Pt St George to pt Arena...none.

.Pt Arena to pt Conception...None.

.Pt Conception to Guadalupe island...None.

.Forecaster Holley/kosier. Ocean forecast branch.