marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 230 PM PDT Fri Sep 20 2019
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
High pressure will remain still anchored to the west of the region and will maintain its ridge across the forecast waters with a relaxed pressure gradient in the short term. High pressure will then move south slightly as it weakens and allow a cold front to move across the northern waters. High pressure will rebuild to the west of the southern waters and in combination with strengthening trough along the California coast, pressure gradient will tighten over the eastern portion of the central California waters and elevate E winds to gale force range. Latest NCEP weather map has high pressure 1027 mb near 40n140w that extends a ridge into the waters. Low pressure 981 mb in the Gulf of Alaska has a cold front that stretches south and passes just west of the high pressure.
Models GFS/NAM/CMC/ukmethr/ecmwfhr have continued to initialize fairly well the observed synoptic surface features with just small differences over the high seas. Otherwise, models have a good agreement on keeping high pressure to the west of the region in the short term. There are some differences in the extended period mainly on the wind speed over the central waters. GFS and CMC have winds reaching gale force threshold while ukmethr has winds to 30 kt and ECMWF is the weakest. Will keep continuity and stay with GFS and will retain the warnings in the extended period.
.Seas...Are relatively large over the southern waters where they range between 6 and 9 ft with a peak at 10 ft near Point Arena and Point Reyes. Nww3 wave model fits well the observed seas and has been quite consistent in previous runs. Ecmwfwave is also close to the the observations and is in a good agreement with nww3 in the short term on keep subsiding seas over the southern waters and then build seas from the northwest Tuesday onwards. Will use enp for seas.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... .pzz800...inner waters from Cape Flattery to Cape Shoalwater... gale possible Wednesday night. .Pzz815...Inner waters from Florence or to point St. George... gale possible Tuesday night into Wednesday night.
.Pz6 California waters... .pzz820...inner waters from point St. George to Point Arena... gale possible Monday night. Gale possible Tuesday night into Wednesday night. .Pzz920...Outer waters from point St. George to Point Arena... gale possible Tuesday night into Wednesday night. .Pzz825...Inner waters from Point Arena to Pigeon Point... gale possible Tuesday night into Wednesday night. .Pzz925...Outer waters from Point Arena to Pigeon Point... gale possible Tuesday night into Wednesday night. .Pzz930...Outer waters from Pigeon Point to Point Piedras Blancas... gale possible Wednesday night.
.Forecaster musonda. Ocean prediction center.