marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 102 PM PDT Thu Aug 16 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Per the 18z NCEP surface analysis a high pressure ridge continued over the opc offshore pz5 and pz6 waters while a low pressure trough was present over inland northern California, extending into southwestern Oregon. The latest ascat high resolution data, where available, revealed 5-15 kt winds over the central pz6 waters.
No change in the forecast thinking as the latest 12z model guidance continues the good agreement that's been seen over the last several days. Hence populated the grids with the 12z GFS winds over the forecast period given the continued model agreement. High pressure ridging continues to be the dominate feature over the offshore waters with low pressure troughing expected to strengthen later Friday and maintain that strength into Monday before weakening late Monday. Continue to expect winds to remain below gale force over the offshore waters through the period, though winds will remain increased over the pz5 and northern pz6 waters late Friday into Monday in response to the tightening pressure gradient due to the interaction of the high pressure ridge with the strengthening low pressure trough.
.Seas...Populated the wave grids with the 12z nww3 over the forecast period given the choice to use the 12z GFS winds over the forecast period.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Holley. Ocean prediction center.