000
AGPN40 KWNM 212133
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
133 PM PST Thu Jan 21 2021

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

.At 20Z,latest available satellite imagery, marine and land
surface observations and analysis detect the center of a large
1032 mb anticyclone situated over the E Pacific near about
44N143W. The closest significant cyclone is a developing 982 mb
cyclone out at about 48N172W, well south of the East Central
Aleutian Island Chain. Across the Pacific Regional waters, a
small near 1011 mb low is situated in the Outer PZ5 waters
between PZZ910, with a stationary frontal boundary extending
Eward along the Snake River Valley towards Idaho and a cold
front extending south into the Outer Central PZ6 waters thence
SWward into the open E Pacific. And SE of that, a coastal trough
is in place in the immediate nearshore waters adjoining the
Central and Southern CA coastline down to the Nearshore waters W
of Central Baja MX.

Given an available afternoon 1910Z ASCAT-HI pass detailed 27-33
kt winds well away from the center W of the low and the Offshore
Pacific waters, it is likely that low end gales are in place just
W of the center across the Central and Southern PZ5 Outer waters
attm. South of that, well sampled areas across the Southern and
Central PZ6 that are beneath the weaker and broad ridging are
experiencing winds between 5 and 20 kt.

In the short term, (tonight thru Sat night), the 1011 mb low
that is in the Central Outer PZ5 waters will continue to slowly
move ESEward and into the Inner Southern PZ5/Northern PZ6 waters
during the evening. As was stated on the am update, both the
GFS/ECMWF and the non-Ncep Ukmet/CMC continue with indications of
low-end gales after 21Z continuing until at least 06Z this
evening in all of the models except the ECMWF but continuing with
gales until at least 15Z Fri am, before the system degrades in
the Nearshore Central CA waters in the afternoon. Thereafter, a
near 1035 mb anticyclone out near 40N144W will hold in place for
Fri night and settle to near 37N145W by 18Z Sat. This will result
in strong subgale north and northwesterlies (30 knotters)
encompassing much of the Pacific Regional waters Fri afternoon
and night, with winds lightening across the PZ5 waters on
Saturday and the strong subgales being confined to the PZ6
waters on Saturday. Given all that for the winds will be using a
50/50 blend of the GFS/ECMWF as they have been close with the
solutions for a several runs for tonight thru Sun 12Z.

For Sat night thru Monday, On Saturday night the ridging will
rebuild to the north intensifying to between 1040-1045 mb aoa
45N154W by 06Z Sun. But ahead of this system a sharp fast moving
cold front will race towards the PZ5 waters reaching the PZ5
Outer waters by 00Z Sunday. By about 0900Z both the 12Z GFS and
ECMWF are developing a near 1005 mb system near the Juan De Fuca
Straits, then moving it only slowly SEwards into the WA State
Nearshore waters throughout the day. The system should begin to
move inland between 00-06Z Monday but will pull the associated
cold front down into the Southern PZ6 waters by 12Z Monday.
Between Saturday night and Sunday night, gales will spread from
north to south behind this front across portions of the PZ5 and
PZ6 waters. Also on Sunday night all of the models once again are
moving the large 1040 mb high southwards to set up shop near
38N143W by Mon 12Z. Given this pattern, gales are indicated
across portion of the PZ6 waters with the exception again of the
ECMWF. The ridge will weaken slightly Mon afternoon and night,
but strong subgale NW winds will continue across much of the PZ6
waters for this period. For this period will not include the
ECMWF but continue with the GFS and a 50/50 combo of the
Ukmet/CMC for SUN 12Z till Tue 12Z.

.Extended, for Monday night thru Thu the pattern will continue
to be quite active thru this period with a series of disturbances
and stronger low pressure ares diving SEward across the Regional
waters, with the GFS indicating a 980 mb low moving NW to SE
while the other 12Z models depict a near 990 mb system moving SE
across the waters Tue thru Wed followed by hints of another
system behind it for Wed into Thu. For this period will return
with a 50/50 blend of the ECMWF with the GFS and cap the winds at
32 knots because there are typically huge differences in timing
and intensity with these solutions.

.SEAS...The 18Z waveheight analysis continued to be well
representative of the 18Z grids that are using the wavewatch 3
models for all points in the Pacific Regional waters. Will use a
50/50 blend of the wavewatch 3 with the ECMWFwave for tonight
thru Sun 12Z, with just the wavewatch utilized for Sun 12Z till
Tue 12Z, then utilizing a 50/50 blends of the aforementioned wave
model grids from Tue 12Z till the end of the FP.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A

.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
.PZZ800...Inner Waters from Cape Flattery to Cape Shoalwater...
Gale Possible Saturday night into Sunday.
.PZZ900...Outer Waters from Cape Flattery to Cape Shoalwater...
Gale Possible Saturday night into Sunday night.
.PZZ805...Inner Waters from Cape Shoalwater to Cape Lookout...
Gale Possible Sunday.
.PZZ905...Outer Waters from Cape Shoalwater to Cape Lookout...
Gale Possible Saturday night into Sunday night.
.PZZ810...Inner Waters from Cape Lookout to Florence OR...
Gale Possible Sunday.
.PZZ910...Outer Waters from Cape Lookout to Florence OR...
Gale tonight.
Gale Possible Sunday into Sunday night.
.PZZ815...Inner Waters from Florence OR to Point St. George...
Gale Possible Sunday.
.PZZ915...Outer Waters from Florence OR to Point St. George...
Gale tonight.
Gale Possible Sunday into Sunday night.

.PZ6 California Waters...
.PZZ820...Inner Waters from Point St. George to Point Arena...
Gale Possible Sunday into Sunday night.
.PZZ920...Outer Waters from Point St. George to Point Arena...
Gale tonight.
Gale Possible Sunday into Monday.
.PZZ825...Inner Waters from Point Arena to Pigeon Point...
Gale Possible Sunday into Monday.
.PZZ925...Outer Waters from Point Arena to Pigeon Point...
Gale Possible Sunday into Sunday night.
.PZZ830...Inner Waters from Pigeon Point to Point Piedras Blancas...
Gale Possible Sunday into Monday.
.PZZ930...Outer Waters from Pigeon Point to Point Piedras Blancas...
Gale Possible Sunday into Monday.
.PZZ835...Inner Waters from Point Piedras Blancas to Santa Cruz Island, CA...
Gale Possible Sunday night into Monday night.
.PZZ935...Outer Waters from Point Piedras Blancas to Santa Cruz Island, CA...
Gale Possible Sunday night.
.PZZ840...Inner Waters from Santa Cruz Island, CA to San Clemente Island, CA...
Gale Possible Monday night.

$$

.Forecaster Futterman. Ocean Prediction Center.