marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 149 PM PDT sun Apr 23 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
The ascat pass from 18z shows winds 25-30 kt over the inner offshore waters south of Point Reyes. Further north a weak low center is moving across the Washington waters with winds to 20 kt south of the center. A ridge axis extends NE across the NW portion of the California waters. The 12z global models have come into very good agreement across the eastern Pacific during the upcoming week. The major influence on the winds and waves will be a combination coastal trough along the California coast and a persistent area of high pressure W of the California waters. Expect the gradient to slowly tightens over the next 48 hours as the trough strengthens. This pattern will persist for the entire forecast period. The strength of the gradient will fluctuate, occasionally interrupting periods of gales. Most the the gales and strongest waves will occur across the southern waters, just west and south of Point Conception. Later in the week the trough will expand north along the California coast, increasing winds to near gale force over the inner offshore waters of the central region as well. Further N, the pattern will remain progressive during the first 3 days as a series of weak lows cross the waters. After day 3 expect high pressure to build NE over much of the pz5 region. I will populate the winds grids using the GFS through 06z Wed, then transition to a 50/50 blend of the 30m GFS and the UKMET.
Seas...both the enp and wam were initialized 1-2 ft too low over portions of the mim region, although for the most part the area of the offshore waters look initialized pretty good. I will populate the wave grids using a blend the two wave models throughout the week.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... .pzz835...inner waters from Point Piedras Blancas to Santa Cruz Island, CA... gale possible Thursday night into Friday. .Pzz840...Inner waters from Santa Cruz Island, CA to San Clemente Island, CA... gale Monday night into Tuesday. Gale possible Tuesday night. Gale possible Wednesday night into Friday.
.Forecaster Shaw. Ocean prediction center.