marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 202 am PDT Wed Oct 17 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Per the 06z NCEP surface analysis a high pressure ridge, associated with a 1024 mb high near 40n131w, was located across the Washington, Oregon and California offshore waters. A low pressure trough was located along the Oregon California coasts. The latest available ascat high resolution data revealed generally 5-15 kt winds across the Washington, Oregon and California offshore waters, though winds up to 20 kt were noted in parts of anz820 in the northern California waters.
The 00z guidance continues the good run-to-run consistency that's been seen over the last several days. So with that noted feel it's reasonable to continue populating the grids with the latest run of the GFS 10m winds, in this case the 00z run, for the 5 day period. Through day 4, anticipate the general low track to remain west of the offshore waters. Then by day 5 an upper level trough looks to begin breaking down the persistent upper level ridge, expected to be a major feature over the offshore waters, which could have impacts beyond the 5 day period. With that noted, the aforementioned upper level ridge, results in surface high pressure being the main feature over the forecast period. A weakening cold front is expected to move into the northwest Washington waters later Friday into Friday night before lifting north as a warm front Saturday into Saturday night. Also anticipate a low pressure trough along mainly the California coast, to persist into late in the period as well. With that noted, still don't see winds reaching warning level criteria over the period, as winds are expected to generally remain 20 kt or less through day 5.
.Seas...The 00z enp and ECMWF wam matched up well with 00z and 06z observations. Additionally given the choice to use the 00z GFS 10m winds, will favor the 00z enp wave heights over the forecast period.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Holley. Ocean prediction center.