marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 1252 PM PDT Thu Jul 30 2015
.Forecast discussion: major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
GOES WV imgry indc a wk upr low just W of the pz6 ofshr wtrs...and a rdg ovr the wtrs alng the coast. Rscat FM 1245z indc a lrg area of N to NE winds to 20 kt ovr the N ptn with a few sml areas up to 25 kt...in the pres grad btwn sfc high pres W of the area and a trof ovr the c wtrs. Crnt sfc rprts indc abt 20 kt as well...mainly ovr the N ptn N of the trof. The 12z GFS winds are init OK when compared with the crnt data...and indc 20 to 25 kt ovr the ofshr wtrs in the 30m bl wnds...and 20 kt in the 10m wnds. The 10m wnds seem init a ltl better...and the 30m wnds look slgtly overdone...esp considering mdl stability indices which indc a stable envrmt...so preferring the more shallow 10m wnds attm. The 12z ECMWF/UKMET are slgtly wkr...and agree somewhat well with the 10m GFS wnds. The 12z Gem/NAM are a ltl stgr...tho not unexpected with their typical high bias. For now planning on using the 12z GFS 10m wnds in the short term...as the GFS is in rsnbly gud agrmt with the rest of the guid.
For the rmndr of the pd...the 12z mdls all indc the wk upr low W of pz5 wl persist thru the pd...and maintain a wk sfc low. However...the mdls indc the low wl drift E twd the rgn in the later part of the pd...tho wl stay W of the pz6 wtrs. The biggest fcst prblm cont to revolve abt anthr upr low movg into the epac FM the gulfak. The GFS has been consistent with it passing just N of the pz5 wtrs by Tue ngt...but the rest of the mdls do not stgly agree with the track of this feature. The 12z ecwmf takes it further SW...and the 12z UKMET is much further N. In fact...the only stg agrmt is with the Gem...and prev runs of the GFS. The biggest impact at the sfc is the intnsty of the wnds alng the coast...as the loc of the sfc rdg acrs pz5 differs in contrast with the ecwmf and UKMET. A sfc low does pass N of the area...with wk caa movg into the N ptn of the was wtrs. This wl lower static stability...allowing a ltl deeper mxg. Attm preferring to stay with the GFS...which has the best sprt...but confdc is low.
.Seas...The 12z mww3 and ecwmf wam are init OK...and agree well into Mon. The ecwmf wam dvrgs FM the nww3 in conjunction with the diff in wx mdls. As a result preferring to stay with the 12z mww3 mdl...which reflects preferred GFS wx mdl trends.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Kells. Ocean prediction center.