000
AGPN40 KWNM 220932
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
232 AM PDT Tue Oct 22 2019

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

At 06z strong high pressure was in place west of the CA waters
with a cold front pushing through the OR waters. Winds across
the OR/WA waters were 10 to 20 kts. Between the strong high and
a coastal trough in CA winds were 15 to 25 kts across much of the
central CA waters. Elsewhere winds were generally 5 to 15 kts.
Seas were 6 to 9 ft from the OR waters to central CA waters. Seas
across the southern CA waters were 7 to 10 ft and seas across
the WA waters were 10 to 14 ft.

The 00z models are in above average agreement across the eastern
Pacific through the forecast period. Gale hazards will be
possible tomorrow night and again on Sat over the
central/northern CA offshore zones. With strong high pressure in
place west of the waters a cold front will slide southward
through the northern waters today and into the CA waters on Wed.
With a CA coastal trough in place and building high pressure
behind the front winds will be increasing in wake of the front
across the central/northern CA waters. Global models have backed
off on the winds with this event compared to the last several
days leading to a decision to drop warning headlines for this
period. Gales remain possible but much less likely with the only
model support coming from the 00z GFS and rather limited at that.
For the short term period through 00Z Fri we leaned a bit more
toward the 00z ECMWF which removed the gale conditions for the
Wed night/Thu morning period.

High pressure weaken on Thu with improving conditions before
another cold front reaches the WA waters by Fri morning. Strong
high pressure will build to the NW of the waters and drive a cold
front southward across the northern waters on Fri and the
southern waters on Sat. The strength of the high...1040
mb...combined with a CA coastal trough will generate a strong
pressure gradient and winds will increase in response from the OR
waters to the central CA waters. Gale conditions will be possible
beginning 12z Sat and continue into late Sat night across the
northern CA and inner southern OR offshore waters. There is above
average confidence in these gales given the strong model
agreement even at such long lead time. Conditions will improve
Sun through Tue as strong high pressure slowly weakens. For the
longer range period we used a blend of the 00z ECMWF/GFS with
good support from the rest of the global models for the gale
conditions on Sat.

Seas...No recent altimeter passes over the waters but both wave
models matching up well with marine observations at this time. We
used the wavewatch through 00z Sat then used a blend of the
wavewatch and EC wave for the rest of the period. Wavewatch was a
bit too aggressive with wave heights late Wed into Thu because
of the higher wind speed forecast for that period so blending in
the ec wave brought that down to a reasonable level.

.EXTRATROPICAL STORM SURGE GUIDANCE...n/a.

.WARNINGS...Preliminary.

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

.PZ6 California Waters...
.PZZ820...Inner Waters from Point St. George to Point Arena...
Gale Possible Saturday into Saturday night.
.PZZ920...Outer Waters from Point St. George to Point Arena...
Gale Possible Saturday night.

$$

.Forecaster Krekeler. Ocean Prediction Center.