marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 849 PM PDT Mon Jul 28 2014
.Forecast discussion: major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Slow changing pattern expected ovr epac ovr next 5 days as an upr low in ern glf of AK overnight into Tue night rptates back twd SW Wed into Sat allowing an upr rdg ovr wrn U.S. Into SW Canada to strengthen...and as a result the inverted trof ovr CA into SW Oregon after initl wkng strengthens Wed into Sat...and wnds incrs off nrn CA/srn Oregon to 25-30 kt by Thu and spread N and S into Sat. One wrinkle is that 18z GFS dvlps gale frc bl wnds in nrn CA ofshr nr cstl area late Fri but other mdls are not on board...with 12z UKMET showing gales off nrn CA Fri night but only in cstl area and the usually robust CMC global only shows Max 1000 mb wnds of 35 kt. Will use 12z GFS for fcst on which grids are based.
Seas...12z/18z wave watch iii appr well initialized and will use for fcst with 12z ECMWF wam only showing minor differences by Wed mainly in cstl wtrs with slgtly higher seas. ----------------------------------------------------------------- Previous discussion...
There is still no indc of conv clds over the region. The radar does not hav any tstms cells ovr most of the region except the far srn region where some lightng is slowly diminshing. Ts Hernan is still moving twd NW and getting closer to the srn wtrs but will not be close enough to pose any mjr threat to the fcst wtrs in the short term and the NHC has more info under tcmep3. At 1800z hgh pres 1026 mb W of the cntrl region nr near 38n136w is still the main synop feature that has maintained a weak ridge NE acrs the nrn wtrs and also se acrs the srn wtrs. Low pres 1014 mb now 120 nm NW of The Wash wtrs is part of a broad low pres area that spans into the Gulf of AK. Inland low pres ovr AZ still has a trof stretching NW acrs cal state into oreg. The Max obs winds are 15 kt. The latst ascat pass at 1804z had Max winds ovr the oreg and nrn cal wtrs at 20 kt.
The glbl mdls hv initialized fairly well and they are initially in decent agrmnt espcly ovr the short. Upperlevel synop features support the sfc features fairly well. Most of the enrgy will remain NW of the region as the ridge persists nr the coast. As such the pres grdnt will contne to be weak and there should be no mjr chgs to the curr fcst.
In the short term the low pres W of the nrn region will move NE into the coast of Canada while the hgh pres will remain nrly stnry W of cntrl region. The pres grdnt will continue to build slowly as hgh pres strengthens but winds will stil remain below gale force.
.Seas...The seas range btwn 4 and 9 ft with hghst seas ovr the cntrl region. The nww3 multi grid WV mdl fits well with the obs seas pattern and S quite close to the ecmwfwave in the short term but mnr diffs in the xtndd prd where the Euro has slightly hgr seas than nww3. Will keep it simple and just use enpwave.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Bancroft/musonda. Ocean prediction center.