000
AGPN40 KWNM 061447
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
747 AM PDT Sat Jun 6 2020

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

Inland trough along the California coast will strengthen while
high pressure will remain anchored to the west of the region as
low pressure moves east to pass just northwest of the Washington
waters with the associated front moving east over the northern
waters in the short term. High pressure will remain to the west
of the southern waters and will extend its ridge northeast as
inland trough weakens in the extended period. Latest NCEP weather
map has high pressure 1027 Mb near 40N145W with its ridge
extending into the southern waters while a trough stretches from
northeast Washington waters through inner Organ waters into
northeast California waters. A cold front lies across the far
southern waters. Seas range between 6 and 9 ft over most of the
region except the northeast Oregon and Washington waters where
seas are just under 6 ft. NWW3 and ECMWFWAVE models have
initialized well the observed seas. The global models are still
in a good agreement in the short term and so will not deviate
from the previous forecast and will retain the warnings over the
central California following GFS guidance for winds and NWW3 for
seas.

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PREVIOUS DISCUSSION...

At 06Z weak low pressure was over the N central CA waters with a
cold front extending SW over the outer central CA waters.
Another low pressure was NW of the WA waters. An ASCAT pass at
around 06Z had winds to 25 kt within about 420 nm of the SW
quadrant of the low. A trof extended SE from the low into outer
WA/OR waters. A broad area of high pressure was W of the outer CA
waters and building E into the CA waters. There was a ASCAT
across the offshore waters at around 04Z which was close to model
guidance with the stronger winds located over the S CA waters
where winds were up to 20 kt. For today low pressure moves into
the WA waters and dissipates into a trof later today into a trof
that moves inland by tonight. The low pressure over the CA waters
moves inland later this morning. A coastal trof develops along
central and S CA later this afternoon with intensification
through tonight into Sun night. Plan to have gales developing
over the inner S CA later Sun afternoon into Sun night with model
guidance similar with strong area of high pressure building in
across the N and central CA waters. For Mon and Mon night a warm
front moves NE over the WA/OR waters. Confidence for gales
developing with the front is low at the moment over the WA
waters. Will have winds to 30 kt with the warm front as it moves
NE and is followed by a cold front that crosses into the outer
WA/OR waters late Mon night into Tue. A weak area of high
pressure builds E over the waters Tue night into Wed. Another
cold front approaches the WA/OR waters later Wed and enters the
waters Wed night. The GFS/ECMWF are in fairly close agreement
with the passage of the front into the waters.

For the grids will use the GFS through about 12Z Mon, then favor
the ECMWF after 12Z Mon.

Seas...For the seas plan to use the Wave watch through 12Z Mon,
then favor the ECMWF wam after 12Z Mon. The model guidance is in
fairly close agreement through the forecast period. The Wave
watch is somewhat higher with the seas over the S CA waters on
Sun into Sun night with the gales anticipated, although not
significantly different.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A.


.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
None.

.PZ6 California Waters...
.PZZ840...Inner Waters from Santa Cruz Island, CA to San Clemente Island, CA...
Gale tonight into Sunday night.

$$

.Forecaster Musonda/Rowland. Ocean Prediction Center.