marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 718 PM PDT Thu Oct 30 2014
.Forecast discussion: major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
No sig changes to the fcst anticipated attm.
Seas...enp version of wwiii within a ft or two over most of the cstl/offshr waters. Model a bit underdone off the srn calif coast where obs showing seas of 6 to 7 ft while model showing 5 to 6 ft.
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18z high resolution ascat-b returned Max winds to 25 kt over outer pzz900 offshore waters also over coastal waters between coast and cold front N of Cape Shoalwater. Sharp mid/upper level trof should continue to move E toward coast over next 36 hrs. 12z models are in good agreement that shrtwv at base of trof will further amplify tonight and Fri as it approaches central and srn CA coast while becoming negatively tilted Fri night. Latest lightning density product shows isolated tstms associated with trof and given depth of feature along with adequate cold air aloft as it moves through offshore waters should see some isolated to scattered tstms late tonight into Fri night. 15z spc sref based probabilities reach 50 to 60 percent over outer central CA waters Fri afternoon. As for winds 12z models all indicate that associated N to NW surge up to 25 to 30 kt should move into pz6 and srn pz5 waters Fri night and Sat. With high pres building W over pz6 waters Sat through sun and coastal trof setting up there continues to be consistency between GFS/ECMWF/ UKMET in maintaining winds up to 25 kt at least off S and central CA. Will be populating with GFS boundary layer or 30m winds through sun as are well supported by 12z ecwmwf and 12z UKMET. Then there continues to be reasonable agreement between GFS/ECMWF/UKMET with next cold front to move through the pz5 waters Mon and Mon night. 12z GFS and 12z UKMET are only slighly faster than 12z ecwmf but all models do indicate winds up to 25 or 30 kt over all pz5 zones Sun night through Mon night. 12z GFS trended somewhat weaker with these pre frontal winds.
By late in the forecast period the 12z models in above avg agreement with cold front stalling from near Cape Lookout SW across srn pz5 waters early Tue...then lifting N was warm front later Tue. Then 12z GFS and 12z ECMWF have come into very good agreement with developing low pres approaching pz5 waters midweek.
Sig WV hgts NW of Vancouver Island and W of Queen Charlottes continue to report about 4 to 5 ft higher than both multigrid wavewatch iii and ECMWF wave model. Over offshore waters models seem to have better handle with sea state and are actually in reasonable agreement through the forecast period. Will be using mww3 sig WV hgts through Mon night before transitioning to 50/50 blend of 12z mww3 and 12z ECMWF wave model Tue through Wed night.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster achorn/Clark. Ocean prediction center.