marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 1246 PM PDT Mon Sep 1 2014
.Forecast discussion: major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Over the short term...the new 12z mdls remain consistent and in rsnbly good agrmt. To the N...after a weak ridge maintains lite winds tonite the mdls all fcst a wkng cold front and/or sfc trof to push se into the pz5 wtrs with an ascd strenthening nwly gradient. A compromise of the 12z GFS/UKMET/ECMWF for this gradient looks rsnbl and as a result stil expect Max ascd winds up to 25-30 kt as prevly fcstd (tho again...smlr to their prev respective runs...per the 12z GFS/UKMET wuld not be surprised to see sm gale force gusts off cp flattery early Tue nite). Further S as the inland trof and high pres to the NW both strengthen slightly the mdls all fcst the nnwly gradient to also strengthen with again every mdl except the usually conservative 12z ECMWF fcstg gale force ascd bl winds to dvlp acrs the NE most pz6 and far se pz5 wtrs late Tue/Tue nite...then persist into early Thu. With the 12z NAM/GFS/Gem fcstg the strongest gradients vs the slightly weaker 12z UKMET/navgem/ECMWF solutions...as a compromise wl use a 80/20 blend of the 12z GFS 30m and 12z ECMWF bl winds thru early Thu (mainly just to tap down the 12z GFS bl winds slightly). So since a smlr blend was used for the prev ofshr fcst package...anticipate making only minor short term chngs to the prev ofshr fcsts.
In the long range...the consensus of the 12z mdls bcms smlr as they all fcst the strong high pres ridge W of the pz5 wtrs to slightly weaken Thu thru Fri nite...whl the low pres trof expands slowly nwd up the Oregon/Washington coasts and gradly weakens. As a result the mdls all fcst the mod strong nnwly gradient to expand nwd and slowly weaken...with a compromise 12z GFS/0z ECMWF solution looking best. Therefore plan on contg to use an 80/20 12z GFS 30m/12z ECMWF bl wind blend for later Thu/Thu nite...then as their diffs bcm minimal wl transition to a 50/50 blend of the 12z GFS 30m/12z ECMWF bl winds for Fri/Fri nite. Then Sat/Sat nite wl populate with all 12z ECMWF bl winds as prefer its less progressive solution for the next aprchg cold front...since its supported better by the 12z UKMET and the latest wpc medium range guidance. So wl be making gnrly small long range chngs in the next ofshr fcst package.
.Seas...With the differences btwn the two mdls being minimal... plan on using a 50/50 blend of the 12z wavewatch iii and 12z ECMWF wam mdls thru Fri nite...with sm slight upward enhancements in the area of gales late Tue into early Thu. Then since the 12z ECMWF solution wl be used wl transition to all 12z ECMWF wam fcst seas Sat and beyond.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... .pzz815...inner waters from Florence or to point St. George... gale Tue night into Wed. Gale possible Wed night into Thu.
.Pz6 California waters... .pzz820...inner waters from point St. George to Point Arena... gale Tue night into Wed. Gale possible Wed night into Thu.
.Forecaster vukits. Ocean prediction center.