marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 1225 am PST Thu Jan 17 2019
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
The 06z surface analysis indicated strong low pressure just west of the southern Oregon offshore waters, with occluded front extending across the Washington waters then inland across western Oregon. The trailing cold front then extended southwest across the central California waters. The latest available ascat passes from around 0450z and 0520z indicated widespread gales across the northern Washington offshore and coastal waters, with another area across the southern Oregon and northern California waters. These were embedded in a larger area of 25 to 30 kt winds covering most of the area except the Southern California waters. GOES satellite imagery and lightning data continue to indicate some strikes in the colder air over the northern and central California waters.
The 00z models continue to be in very good agreement during the immediate short term period today and tonight. There are some differences however with the next strong low which will impact the Washington and Oregon waters later Friday into Saturday. For today and tonight, the models agree moving the strong low west of the southern Oregon waters northeast, passing across the western Washington waters Thursday morning and afternoon. Expect the gale area to lift north through tonight, with winds diminishing to below gale later tonight as the low moves north of the area and gradually weakens. Then the focus turns to the next strong low Friday into Saturday. The 00z GFS and CMC are in very good agreement with the timing and track of the low passing just west of the Washington waters Friday night. The 00z ECMWF and UKMET meanwhile are more progressive compared to the GFS/CMC, and take the low a bit further northwest. The 00z navgem is in between the GFS/CMC and ECMWF/UKMET, and seems to be a decent compromise. With that said, using a 60/40 GFS/ECMWF blend is also close to this, and also maintains decent continuity with previous wind grids with only minor changes to existing warning headlines. Overall, confidence is above average with gales today and tonight, and about average later Friday into Saturday considering the model differences. Then looking ahead to Saturday night and beyond, the 00z GFS is a significant outier as it develops a strong low near the western portion of the Oregon offshore waters late Saturday night, then moves southeast Sunday and Sunday night and inland Monday. Since none of the other models indicate this strong low will lean more toward the non-GFS models during the extended period. In summary, will use 60/40 GFS/ECMWF blend through 21z Saturday, then 00z ECMWF for remainder.
.Seas...The 06z sea state indicated that the observed seas continued to match up better with the ECMWF wam compared to the enp values. Based on observed buoy and ship reports, the enp values are about 3 to 6 ft too high. As of 08z buoy 46059 was reporting 34 ft, while the enp was forecasting about 40 ft. Plan on using the ECMWF wam through today, then will use a 60/40 blend tonight through Saturday similar to wind grids. Then will transition back to ECMWF wam for remainder.
.Extratropical storm surge guidance...Estofs and etss continue to indicate positive storm surge values greater than 1 ft along the Washington and Oregon coasts today. Interested parties should monitor the coastal forecast offices for the specific storm surge information.
.Pz5 Washington/Oregon waters... .pzz800...inner waters from Cape Flattery to Cape Shoalwater... gale today. Gale possible Friday night into Saturday. .Pzz900...Outer waters from Cape Flattery to Cape Shoalwater... gale today. Storm possible Friday night into Saturday. .Pzz805...Inner waters from Cape Shoalwater to Cape Lookout... gale today. Gale possible Friday into Saturday. .Pzz905...Outer waters from Cape Shoalwater to Cape Lookout... gale today. Gale possible Friday. Storm possible Friday night. Gale possible Saturday. .Pzz810...Inner waters from Cape Lookout to Florence or... gale today. Gale possible Friday. .Pzz910...Outer waters from Cape Lookout to Florence or... gale today. Gale possible Friday into Friday night. .Pzz815...Inner waters from Florence or to point St. George... gale today. Gale possible Friday. .Pzz915...Outer waters from Florence or to point St. George... gale today. Gale possible Friday night.
.Pz6 California waters... .pzz820...inner waters from point St. George to Point Arena... gale today. .Pzz920...Outer waters from point St. George to Point Arena... gale today. .Pzz925...Outer waters from Point Arena to Pigeon Point... gale today.
.Forecaster kosier. Ocean prediction center.