Storm Warning 160, NWS Anchorage, AK

224 
FZAK62 PAFC 100015
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
315 PM AKST Fri Dec 9 2022

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-101415-
315 PM AKST Fri Dec 9 2022
.SYNOPSIS FOR CENTRAL BERING SEA...

A 975 mb low at 55N 176E moves over the Chukotsk Peninsula into 
the Chukchi Sea for Sun afternoon. Its front moves across the 
Aleutians and Bering into the Gulf of Alaska by Sun morning. A 
1007 mb North Pacific low moves along the front to 56N 156W at 986
mb by Sun afternoon.

$$

PKZ411-101415-
Bering Sea Offshore West of 180 and East of the International
Dateline-
315 PM AKST Fri Dec 9 2022

...GALE WARNING THROUGH SATURDAY NIGHT...

.TONIGHT...W wind 20 to 35 kt. Seas 12 to 20 ft.
.SAT...W wind 20 to 35 kt. Seas 12 to 19 ft.
.SAT NIGHT...W wind 20 to 35 kt. Seas 10 to 18 ft.
.SUN...SW wind 10 to 25 kt. Seas 7 to 12 ft.
.SUN NIGHT...SE wind 30 to 45 kt. Seas 8 to 13 ft.
.MON...W wind 30 to 45 kt. Seas 14 to 22 ft.
.TUE...NW wind 30 to 45 kt. Seas 20 to 28 ft.
.WED...S wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ412-101415-
Bering Sea Offshore 171W to 180 and North of 56N-
315 PM AKST Fri Dec 9 2022

...GALE WARNING THROUGH SATURDAY NIGHT...

.TONIGHT...S wind 30 to 45 kt. Seas 15 to 21 ft. Rain.
.SAT...W wind 25 to 35 kt. Seas 16 to 20 ft.
.SAT NIGHT...W wind 20 to 35 kt. Seas 12 to 17 ft.
.SUN...W wind 15 to 25 kt. Seas 10 to 16 ft.
.SUN NIGHT...SW wind 25 to 40 kt. Seas 8 to 12 ft.
.MON...S wind 30 to 45 kt. Seas 9 to 16 ft.
.TUE THROUGH WED...NW wind 25 to 40 kt. Seas 13 to 21 ft.

$$

PKZ413-101415-
Bering Sea Offshore 171W to 180 and South of 56N-
315 PM AKST Fri Dec 9 2022

...STORM WARNING TONIGHT...

.TONIGHT...SW wind 35 to 50 kt. Seas 15 to 23 ft.
.SAT...W wind 20 to 35 kt. Seas 12 to 20 ft.
.SAT NIGHT...NW wind 20 kt. Seas 9 to 13 ft.
.SUN...W wind 10 to 25 kt. Seas 8 to 12 ft.
.SUN NIGHT...S wind 30 to 45 kt. Seas 8 to 13 ft.
.MON...S wind 30 to 45 kt. Seas 11 to 19 ft.
.TUE THROUGH WED...W wind 25 to 40 kt. Seas 13 to 27 ft.

$$

PKZ414-101415-
Bering Sea Offshore East of 171W-
315 PM AKST Fri Dec 9 2022

...GALE WARNING TONIGHT...

.TONIGHT...S wind 30 to 45 kt. Seas 10 to 18 ft. Rain and snow.
.SAT...SW wind 15 to 30 kt. Seas 9 to 16 ft.
.SAT NIGHT...W wind 15 to 25 kt. Seas 9 to 14 ft.
.SUN...NW wind 15 to 25 kt. Seas 8 to 12 ft.
.SUN NIGHT...NW wind 15 to 30 kt. Seas 9 to 12 ft.
.MON THROUGH TUE...S wind 25 to 40 kt. Seas 10 to 18 ft.
.WED...W wind 20 to 35 kt. Seas 11 to 19 ft.

$$

738 
FZAK62 PAFC 101257
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
357 AM AKST Sat Dec 10 2022

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-110145-
357 AM AKST Sat Dec 10 2022
.SYNOPSIS FOR CENTRAL BERING SEA....

A 975 mb low at 60N 179W exits towards the Chukotsk Peninsula
by Sat night. A 1002 mb low at 48N 169W on Sat morning moves into
the Western Gulf at 987 mb by Sun afternoon. A 997 mb low at 50N 
168E Sun morning moves to 55N 177E at 990 mb by Mon morning.

$$

PKZ411-110145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
357 AM AKST Sat Dec 10 2022

...GALE WARNING TODAY...

.TODAY...W wind 20 to 35 kt. Seas 12 to 18 ft.
.TONIGHT...W wind 15 to 30 kt. Seas 9 to 15 ft.
.SUN...SW wind 10 to 25 kt. Seas 6 to 11 ft.
.SUN NIGHT...E wind 15 to 30 kt. Seas 6 to 11 ft.
.MON THROUGH TUE...NW wind 20 to 35 kt. Seas 10 to 18 ft.
.WED...N wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ412-110145-
Bering Sea Offshore 171W to 180 and North of 56N-
357 AM AKST Sat Dec 10 2022

...GALE WARNING TODAY...

.TODAY...W wind 25 to 35 kt. Seas 16 to 20 ft.
.TONIGHT...W wind 20 to 30 kt. Seas 12 to 17 ft.
.SUN...W wind 15 to 30 kt. Seas 10 to 16 ft.
.SUN NIGHT...SW wind 15 to 30 kt. Seas 5 to 10 ft.
.MON...S wind 20 to 35 kt. Seas 8 to 16 ft.
.TUE...N wind 10 to 25 kt. Seas 11 to 18 ft.
.WED...NW wind 25 to 40 kt. Seas 8 to 16 ft.

$$

PKZ413-110145-
Bering Sea Offshore 171W to 180 and South of 56N-
357 AM AKST Sat Dec 10 2022

...GALE WARNING TODAY...

.TODAY...W wind 25 to 35 kt diminishing to 15 to 25 kt in the
afternoon. Seas 12 to 20 ft.
.TONIGHT...W wind 20 kt. Seas 8 to 13 ft.
.SUN...W wind 10 to 25 kt. Seas 7 to 11 ft.
.SUN NIGHT...S wind 20 to 35 kt. Seas 8 to 13 ft.
.MON...SW wind 20 to 35 kt. Seas 10 to 18 ft.
.TUE...W wind 15 to 30 kt. Seas 9 to 15 ft.
.WED...NW wind 30 to 45 kt. Seas 11 to 19 ft.

$$

PKZ414-110145-
Bering Sea Offshore East of 171W-
357 AM AKST Sat Dec 10 2022

...GALE WARNING TODAY...

.TODAY...S wind 20 to 35 kt in the morning becoming SW 15 to 30 kt. 
Seas 10 to 16 ft.
.TONIGHT...W wind 15 to 25 kt. Seas 9 to 14 ft.
.SUN...NW wind 15 to 25 kt. Seas 8 to 12 ft.
.SUN NIGHT...W wind 15 to 30 kt. Seas 7 to 12 ft.
.MON...SW wind 15 to 30 kt. Seas 8 to 16 ft.
.TUE...SE wind 10 to 25 kt. Seas 10 to 18 ft.
.WED...NE wind 15 to 30 kt. Seas 9 to 17 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
339 PM AKST Thu Dec 8 2022

.ANALYSIS AND UPPER LEVELS...

A negatively tilted upper-level trough extends from the Chukchi
Sea to the Alaska Panhandle. A surface low at the base of this
trough has now exited the region and continues to move over the
eastern Gulf. The cyclonic flow and moisture advection resulting
in areas of light snow over the Copper River Basin this morning
are also both weakening, allowing for snow to taper off across
most locations over the eastern half of Southcentral. Elsewhere
across Southcentral, a developing northerly flow aloft, cold air
advection, and southward track of various vorticity maxima, are
all combining to produce stout offshore winds through favored gap
locations. Winds today have routinely gusted between 35 and 45
mph for Seward and Whittier, with 25 to 35 mph for Valdez.

Out west, conditions are a bit more tranquil, with broad
northwesterly flow and occasional snow showers across the AKPen
and eastern Aleutian Chain in the wake of an elongated surface
low moving southeast away from the AKPen. An upper-level ridge is
building across the central Bering with the next storm system
spinning up well southwest of Attu.

&&

.MODEL DISCUSSION...

Latest operational runs are in good agreement with the placement
of synoptic-scale features through the first half of the weekend.
Divergence in the models begins Sunday as a potent upper-level
wave moves from the North Pacific into the western Gulf and its
potential interaction with a weakening wave and associated
surface front moving across Southwest Alaska. Models are all
indicating that this feature will likely tap into a deep moisture
source as it begins to move toward the Southern Mainland. The
biggest challenge will be placement of the synoptic surface
features and where the more significant areas of precipitation
(likely snow) develops moving into the latter half of the weekend.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist. There is the
potential for an increase in northeasterly winds with occasional
gusts 15 to 20 kt early Friday morning.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Cold air advection (CAA) will impact the region at the onset of
the forecast period. Anchorage, the Mat-Su valleys and the Copper
River Basin will be brutally cold and dry tonight, Friday and
Saturday. We are monitoring a low that is currently in the North
Pacific that will push across the Bering and the leading edge of
the precipitation shield will hit Kodiak Saturday morning. By
Sunday morning the remnant moisture from this system will have
moved up Cook Inlet bringing another round of precipitation to the
Kenai Peninsula. The models are not in lock step regarding the
amount of snow that Anchorage can anticipate from this system on
Sunday. The evolution of this system is actively being monitored
with each new model run, but this is clearly a system of interest
for the Anchorage Bowl.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

Fairly quiet weather through Friday as a ridge to the west
produces northerly flow across the area. A weak shortwave will
skirt parts of the Kuskokwim Delta with a few snow flurries
possible through tonight. A frontal system will approach the area
Friday night and Saturday morning with winds increasing from the
southeast. This front will bring light snow to the Kuskokwim Delta
late Friday night into Saturday with 1 to 5 inches expected
through Friday evening. Strong winds up to 40 knots will produce
blowing snow with visibilities down to a half mile mainly from
coastal areas inland towards Bethel. Temperatures will warm into
the lower and mid 30s by Saturday afternoon ending the threat of
blowing snow for the Kuskokwim Delta. This front will also move
into Bristol Bay Saturday morning with blowing snow down to a half
mile expected from Togiak to the Dillingham area. Snowfall of 4
to 8 inches is expected through Saturday evening from Koliganek to
Dillingham and Togiak.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

High Pressure is expected across the eastern Bering through Friday
with gusty northerly winds on the south side of the AKPen
decreasing by Friday morning. A strong low pressure system will
move towards the western Aleutians and Bering Sea bringing rain
and gale force winds with storm force gusts tonight and Friday.
The front will push eastward across the Bering and Aleutians
through Saturday morning with gale force winds. The AKPen will
also see gusty southeast winds and rain Friday night and Saturday
morning. Behind the front colder air will move across the Bering
on Saturday.

&&

.LONG TERM FORECAST (Days 4 through 7: Monday through
Thursday)...

The long term begins Sunday night into Monday with a highly-
amplified pattern in place with an potent surface low and
associated upper-level wave situated over the western Gulf. These
features will be tapping into an impressive moisture plume that is
expected to lend to significant snowfall amounts across much of
Southcentral for Monday. There is still some uncertainty as to the
position of the low and its associated front, with the GFS pushing
the front right to the immediate coast. If the front does make it
onshore, there will likely be a changeover of snow to rain for
coastal locations like Seward and Whittier. However, with cold air
in place initially, if warmer air does not make over the region,
as other models are suggesting, the precipitation should remain
all snow for along the coast.

This system departs on Tuesday as another highly amplified upper-
level ridge moves from the Bering east to the western half of the
state. Both the GFS and EC show this ridge quickly moving east as
yet another upper-level trough moves across the Bering. A surface
low is expected to lift north across the eastern coast of Russia,
with its front moving into the eastern Bering by Tuesday
afternoon. As the front occludes, a shortwave lifting north from
the Pacific looks to spin up a new surface low along the front and
drive the low northward. This solution, although slightly varying
between the GFS and EC, would likely bring warmer air aloft
northward across the state, and potentially introduce
precipitation type issues across the Southern Mainland for
midweek.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 155 161.
MARINE...Gale Warning: 119-121 127-132 136 138 150 155 165 170-181
                       185 351 352 411-414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...TM
SOUTHCENTRAL ALASKA...PJS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RC
LONG TERM...TM