marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 722 am PDT Fri Jun 23 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Coastal low pressure trough has continued overnight weakening trend and northward shift, and now lies along the far northern CA and Oregon and Washington coasts. The coastal trough has also shed a weak surface low centered near 34n126w / 1008 hpa along the outer fringes of zone 935.
Buoy and ship obs are sparse in the vicinity of the strongest pressure gradients, but as expected, the few in the area have reported a steady decline in surface winds and gusts overnight into this early morning. Most notably buoy 46015 just off cape blano was reporting 23g29 at 12z. Recent 12z hrrr and 12z 4km NAM guidance both initialized winds 30 kt or below, and overnight guidance from the UKMET and ECMWF both suggested similar below- gale winds at 12z this morning.
Based on current observations, forecast trends, and recent model guidance, feel comfortable scrubbing the ongoing Gale Warning and removing all headlines from the grids. The previous forecasts ended the headline at 18z later this morning, so this does not represent a major forecast change in the update. Otherwise, no problems with the ongoing grids through the end of the period Tue night. Will re-evaluate entire forecast with upcoming 12z global suite.
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The ascat pass from 05z indicates gale conditions across the northern California waters, extending to the far se portion of the Oregon waters. South of Point Reyes the winds are variable 15 kt or less. An altimeter pass from 04z shows seas to 18 ft across the California waters. The 00z global models are all in very good agreement during the upcoming week across the offshore waters. The forecast philosophy hasn't changed in the past several days. The pressure gradient across the northern California waters that has been producing gales has started to relax overnight. The areal extent of the gales have diminished somewhat, an will continue to do so over the next couple of days. I expect gale winds to linger into this morning before diminishing to 30 kt this afternoon. Seas will continue to slowly subside across the region as well. Much of the region will diminish to winds less than 15 kt, the exception being across the pz5 waters which will maintain a northern gradient 15-25 kt throughout the remainder of the week. Late in the week the coastal trough will begin to strengthen once again, increasing winds to 25-30 kt over the inner waters late in the period. I will continue the trend of populating the wind grids using the 10m GFS throughout the period.
Seas...both the enp and wam initialized well across the region for the most part, and am expecting the models to perform well this upcoming week. I am populating the wave grids using the enp throughout the forecast period.
Extratropical storm surge guidance: N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Collins/Shaw. Ocean prediction center.