HS 102

marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 710 am PDT Wed 19 Jun 2013

.Forecast discussion: major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.

Weak low pres currently over the Washington offshore waters will move NE and inland later today and tonight. One weak cold front will then move across the pz5 waters Sat...followed by another weak front sun. Farther S...a low pres trof along the srn California coast is currently combining with high pres centered W of the pz6 waters to produce NW winds up to 35 kt across portions of the central and srn California offshore waters with the strongest conditions W of Point Conception. Minimal gales will continue into late Thu and then weaken. Strongest winds across the srn and central pz6 waters will then remain near 30 kt through sun. Current warnings look reasonable and few changes should be needed on the next offshore forecast.

The multigrid nww3 looks reasonable with the seas and will be followed fairly closely during the forecast period.

Extratropical storm surge guidance...N/A.

----------------------------------------------------------------- Previous discussion

At 19/0600z the main synop features affecting the region are the low pres 1013 mb ovr wash wtrs that has a trof strchng SW acrs the oreg and nrn CA wtrs. Hgh pres 1029 mb cntrd apprx 780 nm W of the cntrl CA wtrs has a ridge into most of the CA wtrs. Inland low pres 998 mb ovr AZ has a trof xtndg NW acrs CA state and that has maintained a tight pres grdnt ovr the ern parts of the srn CA wtrs where the obsvd winds are reachng gale force. The latst ascat pass at 0500z and even the previous pass at 1741z both showed gale force winds ovr the same area.

The glb mdls agree on movng the low pres ovr the nrn wtrs inland while the hgh pres will drift E and still maintain a ridge acrs the region. The inland low pres trof will persist and that will keep the pres grdnt tight ovr the srn wtrs. So the gales wil persist into Thu nght ovr the far ern parts of the se wtrs. Will add gales to pt Arena to pt Conception region starting tonight ovr the far se parts. Hghst winds will be E of the wtrs. In the xtndd period the hgh pres will pesrsist W of the region but the pres grdnt will become slack and keep winds below gale force. Will stay with GFS for this fcst pckge.

Seas...the seas are hgst ovr the ern parts of the srn ac wtrs peaking at 10 ft. The nww3 multi grid wave mdl has a very close seas pattern to the obsvd one and is close to the ecmwfwave. So will stay close to it. The seas will remain hgst ovr the srn wtrs peaking at 12 ft.

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...none. .Cape Lookout to Pt St George...None.

.Pz6 California waters... .Pt St George to pt Arena...none. .Pt Arena to pt Conception...Gale tonight into Thu..hi cnfdnc. .Pt Conception to Guadalupe island...Gale today into Thu...MDT to hi cnfdnc. $$

.Forecaster nolt/musonda. Ocean prediction center.