marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 830 am PDT Mon Oct 22 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
A weak high pressure ridge was across the northern and central areas of the offshore waters this morning. A trof was across CA and extended into or. A cold front was about 400 nm W of the northern and central offshore waters. Strongest winds this morning were along the inner waters of the southern central into the southern CA waters with winds to 20 kt. By tonight the cold front weakens as it approaches the central and northern offshore waters and moves E over the waters. Will continue with gales over the outer WA waters for tonight in advance of the front. The front weakens as it moves into the inner waters of the WA/OR waters later tonight into Tue.
For the update will not be making any changes for now with prior grids looking good through tonight and the remainder of the forecast period.
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The 06z surface analysis indicated a high pressure ridge across the Washington and Oregon offshore waters and the western portion of California waters. A weak trough extended along the central and Southern California coast. A cold front extended from low pressure near 54n138w south along 140w. The latest available ascat passes from around 0445z and 0525z indicated several small areas of 20 kt over the central and Southern California coastal waters southwest of Monterey Bay and near The Channel islands. Otherwise winds were 15 kt or less.
No significant changes from previous forecast reasoning as the 00z models are in very good agreement through most of the forecast period. The main focus is over the Washington and Oregon waters as several fronts will impact the area. The cold front mentioned above will move east today and tonight, and will maintain the marginal gales for the outer northern Washington waters as hireswarw and hireswnmn both indicate gales tonight. High pressure ridge will then build across area briefly Tuesday and Tuesday night before next strong front moves into the Washington and Oregon waters Wednesday and Wednesday night. Most of the models, including the GFS continue to indicate gales ahead of the front over the outer Washington waters and plan to maintain these gales. Looking ahead to the end of the forecast period, the GFS indicates another low passing just northwest of the Washington waters Friday night while the other models do not. Will continue to lean more to the ECMWF here. In summary, will populate wind grids using the 00z GFS through 12z Friday, except will use previous grids 00z to 12z tonight, then will use 00z ECMWF from 12z Friday and beyond. Overall, condidence in gales is above average.
.Seas...The 06z sea state analysis indicated that observed seas continue to be within a foot of the enp forecast values. Similar to winds, will use enp through 12z Friday, then ECMWF wam for remainder.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... .pzz900...outer waters from Cape Flattery to Cape Shoalwater... gale tonight. Gale possible Wednesday into Wednesday night. .Pzz905...Outer waters from Cape Shoalwater to Cape Lookout... gale possible Wednesday.
.Pz6 California waters... None.
.Forecaster Rowland/kosier. Ocean prediction center.