Marine Interpretation Message
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000
AGPN40 KWNM 220246
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
746 PM PDT Sat Sep 21 2019

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

No significant changes to the forecast or headlines are planned
at this time.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

High pressure will persist to the west of the region and its
ridge will remain across the forecast waters with a relaxed
pressure gradient in the short term. High pressure will shift
slightly south while weakening and that will let a cold front
move east over the northern waters. High pressure will rebuild
just west of the southern waters as inland trough strengthen
along the California coast forcing pressure gradient to tighten
over the eastern portion of the central California waters and
elevate winds to gale force range. Current NCEP weather map now
has elongated high pressure with one center 1027 MB near 38N145W
with a ridge extending east into the northern waters. Inland low
pressure 1011 MB over southern California extends trough along
California coast. Meanwhile, Low pressure 985 MB in the Gulf of
Alaska has a cold front that stretches south and now lies 120 NM
west of the washington waters.

Models GFS/NAM/CMC/UKMETHR/ECMWFHR have initialized fairly well
the latest observed synoptic surface features with just small
differences over the high seas. Otherwise, models have a good
agreement on keeping high pressure to the west of the region in
the short term. There are still some differences in the extended
period mainly on the wind speed over the central waters. GFS and
CMC still have winds reaching gale force threshold while UKMETHR
now has winds to 30 KT and ECMWF is still the weakest. Will
maintain continuity and use GFS and will retain the warnings in
the forecast.

.SEAS...are still relatively large over the southern waters where
they range between 6 and 9 ft with a peak at 10 ft near Point
Arena and Point Reyes. NWW3 wave model fits well the observed
seas and has been quite consistent in previous runs. ECMWFWAVE is
also close to the the observations and is in a good agreement
with NWW3 in the short term on keep subsiding seas over the
southern waters and then build seas from the northwest Tuesday
onwards. Will use ENP for seas.


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



.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
.PZZ800...Inner Waters from Cape Flattery to Cape Shoalwater...
     Gale Possible Wednesday night into Thursday night.
.PZZ900...Outer Waters from Cape Flattery to Cape Shoalwater...
     Gale Possible Wednesday night into Thursday night.
.PZZ805...Inner Waters from Cape Shoalwater to Cape Lookout...
     Gale Possible Wednesday night.
     Gale Possible Thursday night.
.PZZ905...Outer Waters from Cape Shoalwater to Cape Lookout...
     Gale Possible Wednesday night into Thursday night.
.PZZ910...Outer Waters from Cape Lookout to Florence OR...
     Gale Possible Thursday night.
.PZZ815...Inner Waters from Florence OR to Point St. George...
     Gale Possible Tuesday night into Wednesday.
.PZZ915...Outer Waters from Florence OR to Point St. George...
     Gale Possible Thursday night.

.PZ6 California Waters...
.PZZ820...Inner Waters from Point St. George to Point Arena...
     Gale Possible Monday night into Thursday night.
.PZZ920...Outer Waters from Point St. George to Point Arena...
     Gale Possible Tuesday night into Wednesday night.
.PZZ825...Inner Waters from Point Arena to Pigeon Point...
     Gale Possible Tuesday into Thursday night.
.PZZ925...Outer Waters from Point Arena to Pigeon Point...
     Gale Possible Tuesday night into Wednesday night.

$$

.Forecaster Achorn/Musonda. Ocean Prediction Center.


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