Marine Interpretation Message
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000
AGPN40 KWNM 171454
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
754 AM PDT Thu Aug 17 2017

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

Northerly winds prevail off the northern California and southern
Oregon coast this morning between an inland trough and high
pressure analyzed near 40N141W at 12Z. Earlier ASCAT passes from
05Z/06Z showed 20 to 25 kt winds over our outer waters with 25 to
30 kt winds near the coast extending into our inner zones west
and southwest of Point Saint George.

The biggest change with this forecast update was dropping the
gale warning for PZZ820 on Friday night. While gales are still
expected over the adjacent coastal waters, the latest model
trends indicate winds should remain below warning criteria over
our inner offshore zone. Otherwise, will stick with the inherited
grids as they remain consistent with the 00Z/06Z GFS and 00Z
ECMWF winds. Still have above average confidence for an extended
gale event from Saturday night into Sunday night in PZZ820. The
00Z/06Z guidance remains in excellent agreement regarding the
timing and extent of the gales. Strong high pressure will persist
west of the southern PZ5/northern PZ6 waters through Sunday before
weakening and moving southwest Sunday night into Monday, finally
relaxing the offshore gradient.


.SEAS...Overall, the 06Z NWW3 ENP and 00Z ECMWF WAM appear to have
initialized well over most of the area. Applied a slight boost to
the ENP waves through tomorrow to boost seas off the coast of
northern California and match up better with the adjacent coastal
waters. Otherwise, will stick with the inherited ENP grids at
this time. The models continue to produce similar results with
the anticipated gales this weekend, with the ENP/WAM both showing
seas peaking around 16 ft on Sunday.


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


.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
     None.

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

$$

.Forecaster Reinhart. Ocean Prediction Center.



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