264
AGPN40 KWNM 250315
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
815 PM PDT Wed Apr 24 2019

.FORECAST DISCUSSION...Major features/winds/seas/significant
.weather for the North Pacific N of 30N and E of 150W.

Per the 00Z NCEP surface analysis a 1033 mb high was NW of the
Washington and Oregon waters near 49N133W, with its ridge
extending over the waters and down into the northern California
waters. A cold front was located over the central California
waters, with another separate high pressure ridge over the
southern waters. A 1009 mb low was located over California near
40N123W, with a low pressure trough extending SW from the low
center across interior California. At 00Z buoy 46089 in the
Oregon offshore waters reported 15 kt winds, while over
California waters, two ships in the central parts reported 20 kt
winds and buoy 46047 in the southern part reported 10 kt winds.

Will use a 75/25 blend of the old grids and 00Z Warw through
26/00Z just to have a bit of refreshed data in the forecast. But
otherwise, no other changes will be made to the ongoing forecast
given the 18Z GFS/NAM agreement with the 12Z model package, which
itself continued the fairly good agreement seen over the last few
runs. Hence, current warning headlines will remain as is for this
update. Please see the previous discussion below for additional
information.

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PREVIOUS DISCUSSION...

The ASCAT pass from 19Z shows winds 25-30 kt along the northern
California coast. The forecast pattern across the eastern Pacific
remains very stable, and that isn`t likely to change during the
upcoming week. An area of high pressure will persist W of the
California waters with an associate ridge axis extending N-NE. A
low pressure trough will continue to be a major influence along
the California coast. The strongest pressure gradient over the
upcoming week will occur along the northern and central
California coast, with gales first beginning in the coastal
zones, then expanding into the inner offshore waters. Gales are
likely to begin Friday night and continue through Sun night
before the gradient weakens enough to cause winds to drop below
gale force. Not much is expected to happen across the PZ5 waters
during the upcoming week. A weak series of short-waves will take
a swipe at the region, although most of the energy will be N of
the area. Enhanced winds to 30 kt over the NE portion of the
Washington waters will occur at times as a trough forms along the
coast of Vancouver island.

Seas...Not much difference among the ENP and WAM is forecast the
upcoming week and I decided to populate the wave grids using a
blend of the two wave models.

.EXTRATROPICAL STORM SURGE GUIDANCE...


.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
.PZZ815...Inner Waters from Florence OR to Point St. George...
Gale Possible Saturday night into Sunday night.

.PZ6 California Waters...
.PZZ820...Inner Waters from Point St. George to Point Arena...
Gale Possible Friday night into Sunday night.

$$

.Forecaster Holley/Shaw. Ocean Prediction Center.