marine weather discussion for N Pacific Ocean NWS ocean prediction center Washington DC 805 PM PDT Mon Apr 23 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Pacific N of 30n and E of 150w.
Ascat data is still unavailable, but the latest available surface observations are close to model forecast fields. An altimeter pass from 19z or about 5 hours old indicated a swath of seas 5 to 9.5 ft from the Washington coastal waters SSW through pzz925 highest in the latter zone, matching up well with the grids based on the 12z enp wavewatch iii.
The overall pattern over the eastern Pacific is expected to remain weak during the forecast period. At this time I am not expecting to make any changes to the current grids or associated text forecasts. ----------------------------------------------------------------- Previous discussion...
The current satellite pictures show a nearly stationary front W of the waters. The front will continue to weaken over the next 24 hours while a weak low center forms along the front. The low will gradually sink southward as the frontal boundary dissipates. A second low center will form in the low pressure trough over central California and move W offshore on day 2. The weak low center is expected to remain nearly stationary W of the waters for a couple more days before tracking NE across the region. A NW flow will gradually envelop the region toward the end of the period. The 12z global models are in pretty good agreement, especially the GFS and ECMWF. The UKMET is the outlier, especially later in the period. I will use the same model blend as the past couple of days. I will populate the wind grids using the 10m GFS through 12z Wed, then transition to the ECMWF for the remainder of the week.
Seas...both the enp and wam appear to forecast reasonably well during the upcoming week, depending the their associated wind forecast. I will populate the wave grids using the corresponding model to match the winds.
.Extratropical storm surge guidance...N/A.
.Pz5 Washington/Oregon waters... None.
.Pz6 California waters... None.
.Forecaster Bancroft/Shaw. Ocean prediction center.