Storm Warning 154, NWS Anchorage, AK

112 
FZAK62 PAFC 130033
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
333 PM AKST Tue Dec 12 2023

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.

PKZ499-131430-
333 PM AKST Tue Dec 12 2023
.SYNOPSIS FOR CENTRAL BERING SEA...

Several troughs move over the Eastern Bering through Thu morning.
High pressure moves across the Bering into Western Alaska through
Thu afternoon. A 971 mb North Pacific low moves across Central 
Kamchatka at 962 mb for Thu afternoon. Its front sweeps into the 
Central Aleutians and Bering through Thu afternoon.

$$

PKZ411-131430-
Bering Sea Offshore West of 180 and East of the International
Dateline-
333 PM AKST Tue Dec 12 2023

...STORM WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...E wind up to 20 kt becoming SE 15 to 30 kt after
midnight. Seas 8 ft. Rain and snow.
.WED...SE wind 35 to 50 kt. Seas 8 to 13 ft building to 11 to 19
ft in the afternoon. Rain and snow.
.WED NIGHT...S wind 35 to 50 kt. Seas 15 to 20 ft. Rain and snow.
.THU...SW wind 15 to 25 kt. Seas 13 to 19 ft.
.THU NIGHT...SW wind 10 to 20 kt. Seas 13 to 17 ft.
.FRI THROUGH SAT...SW wind 10 to 20 kt. Seas 10 to 14 ft.
.SUN...NE wind 15 to 30 kt. Seas 6 to 9 ft.

$$

PKZ412-131430-
Bering Sea Offshore 171W to 180 and North of 56N-
333 PM AKST Tue Dec 12 2023

...STORM WARNING WEDNESDAY NIGHT...

.TONIGHT...N wind 15 to 30 kt. Seas 8 to 13 ft. Freezing spray N of
58N.
.WED...NE wind 10 to 25 kt becoming E 20 to 35 kt in the
afternoon. Seas 8 to 13 ft. Freezing spray N of 58N.
.WED NIGHT...SE wind 35 to 50 kt. Seas 10 to 18 ft. Snow and rain.
.THU...SE wind 30 to 45 kt. Seas 11 to 19 ft.
.THU NIGHT...SW wind 20 to 35 kt. Seas 11 to 16 ft.
.FRI THROUGH SAT...W wind 10 to 20 kt. Seas 9 to 14 ft.
.SUN...NW wind up to 15 kt. Seas 5 to 8 ft.

$$

PKZ413-131430-
Bering Sea Offshore 171W to 180 and South of 56N-
333 PM AKST Tue Dec 12 2023

...GALE WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...N wind 10 to 25 kt. Seas 8 to 12 ft.
.WED...NE wind 10 to 25 kt becoming SE 20 to 35 kt in the
afternoon. Seas 7 to 12 ft. Snow and rain.
.WED NIGHT...SE wind 25 to 40 kt. Seas 9 to 14 ft. Rain and snow.
.THU...SW wind 20 to 35 kt. Seas 10 to 16 ft.
.THU NIGHT...W wind 10 to 20 kt. Seas 8 to 12 ft.
.FRI THROUGH SUN...SW wind up to 20 kt. Seas 6 to 11 ft.

$$

PKZ414-131430-
Bering Sea Offshore East of 171W-
333 PM AKST Tue Dec 12 2023

...GALE WARNING THROUGH WEDNESDAY NIGHT...

.TONIGHT...N wind 30 to 40 kt. Seas 14 to 19 ft. Freezing spray N of
56N. Widespread snow showers.
.WED...N wind 25 to 40 kt. Seas 11 to 19 ft. Freezing spray N of 56N.
.WED NIGHT...N wind 20 to 35 kt becoming NE 10 to 25 kt after
midnight. Seas 9 to 14 ft. Freezing spray N of 56N.
.THU...E wind 20 to 35 kt. Seas 6 to 11 ft.
.THU NIGHT...SE wind 20 to 35 kt. Seas 7 to 12 ft.
.FRI THROUGH SUN...W wind up to 20 kt. Seas 6 to 11 ft.

$$

097 
FZAK62 PAFC 131221
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
321 AM AKST Wed Dec 13 2023

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.

PKZ499-140215-
321 AM AKST Wed Dec 13 2023
.SYNOPSIS FOR CENTRAL BERING SEA...

A 971 mb low at 53N 163E moves into Kamchatka at 953 mb for Thu 
morning. Its front sweeps into the Central Aleutians and Bering 
through Thu afternoon.

$$

PKZ411-140215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
321 AM AKST Wed Dec 13 2023

...STORM WARNING THROUGH TONIGHT...

.TODAY...SE wind 35 to 50 kt. Seas 8 to 13 ft building to 11 to
19 ft in the afternoon. Rain and snow.
.TONIGHT...S wind 35 to 50 kt. Seas 15 to 21 ft. Rain and snow.
.THU...SW wind 15 to 25 kt. Seas 15 to 20 ft.
.THU NIGHT...SW wind 10 to 25 kt. Seas 14 to 17 ft.
.FRI THROUGH SAT...W wind 10 to 25 kt. Seas 8 to 16 ft.
.SUN...NE wind 15 to 30 kt. Seas 8 ft.

$$

PKZ412-140215-
Bering Sea Offshore 171W to 180 and North of 56N-
321 AM AKST Wed Dec 13 2023

...STORM WARNING TONIGHT...

.TODAY...NE wind 10 to 25 kt becoming E 20 to 35 kt in the
afternoon. Seas 7 to 12 ft.
.TONIGHT...SE wind 35 to 50 kt. Seas 9 to 17 ft. Snow and rain.
.THU...S wind 30 to 45 kt. Seas 11 to 19 ft. Rain and snow.
.THU NIGHT...W wind 20 to 35 kt. Seas 12 to 17 ft.
.FRI...SW wind 10 to 25 kt. Seas 9 to 14 ft.
.SAT THROUGH SUN...NW wind up to 15 kt. Seas 6 to 10 ft.

$$

PKZ413-140215-
Bering Sea Offshore 171W to 180 and South of 56N-
321 AM AKST Wed Dec 13 2023

...GALE WARNING THROUGH THURSDAY...

.TODAY...NE wind 10 to 25 kt becoming SE 20 to 35 kt in the
afternoon. Seas 7 to 12 ft. Snow and rain.
.TONIGHT...SE wind 25 to 40 kt. Seas 8 to 16 ft. Rain and snow.
.THU...S wind 20 to 35 kt becoming SW 15 to 25 kt in the
afternoon.
Seas 11 to 16 ft. Rain.
.THU NIGHT...W wind 10 to 25 kt. Seas 9 to 14 ft.
.FRI THROUGH SUN...SW wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ414-140215-
Bering Sea Offshore East of 171W-
321 AM AKST Wed Dec 13 2023

...GALE WARNING THROUGH THURSDAY...

.TODAY...N wind 25 to 40 kt. Seas 11 to 19 ft. Freezing spray.
.TONIGHT...N wind 20 to 35 kt becoming NE 10 to 25 kt after
midnight. Seas 8 to 13 ft. Freezing spray.
.THU...E wind 20 to 35 kt. Seas 6 to 11 ft. Freezing spray. Rain.
.THU NIGHT...SE wind 25 to 40 kt. Seas 7 to 12 ft.
.FRI THROUGH SUN...W wind 10 to 25 kt. Seas 6 to 11 ft.

$$

920 
FZAK62 PAFC 140043
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
343 PM AKST Wed Dec 13 2023

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.

PKZ499-141415-
343 PM AKST Wed Dec 13 2023
.SYNOPSIS FOR CENTRAL BERING SEA...

A 960 mb Kamchatka low sweeps its front across the Aleutians and 
Bering through Fri morning. A series of weak lows develop along
the front. 

$$

PKZ411-141415-
Bering Sea Offshore West of 180 and East of the International
Dateline-
343 PM AKST Wed Dec 13 2023

...STORM WARNING TONIGHT...

.TONIGHT...S wind 40 to 55 kt. Seas 15 to 22 ft. Rain and snow.
.THU...SW wind 15 to 25 kt. Seas 15 to 19 ft. Snow showers.
.THU NIGHT...SW wind 15 to 25 kt. Seas 14 to 18 ft.
.FRI...SW wind up to 20 kt. Seas 11 to 15 ft.
.FRI NIGHT...SW wind 10 to 20 kt. Seas 11 ft.
.SAT...W wind up to 20 kt. Seas 8 to 11 ft.
.SUN...NE wind 15 to 30 kt. Seas 8 ft.
.MON...N wind 20 to 35 kt. Seas 10 to 18 ft.

$$

PKZ412-141415-
Bering Sea Offshore 171W to 180 and North of 56N-
343 PM AKST Wed Dec 13 2023

...STORM WARNING THROUGH THURSDAY...

.TONIGHT...SE wind 35 to 50 kt. Seas 10 to 18 ft. 
Freezing spray N of 57N. Snow.
.THU...S wind 35 to 50 kt. Seas 12 to 20 ft. 
Freezing spray N of 57N in the morning. Snow.
.THU NIGHT...W wind 20 to 35 kt. Seas 12 to 16 ft.
.FRI...SW wind 10 to 25 kt. Seas 9 to 15 ft.
.FRI NIGHT...SW wind 15 kt. Seas 8 to 12 ft.
.SAT THROUGH SUN...NW wind up to 15 kt. Seas 6 to 10 ft.
.MON...NE wind 20 to 30 kt. Seas 8 to 13 ft.

$$

PKZ413-141415-
Bering Sea Offshore 171W to 180 and South of 56N-
343 PM AKST Wed Dec 13 2023

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...SE wind 30 to 45 kt. Seas 9 to 16 ft. Rain and snow.
.THU...SW wind 25 to 40 kt becoming W 15 to 25 kt in the
afternoon. Seas 10 to 16 ft. Rain.
.THU NIGHT...SW wind 20 kt. Seas 9 to 13 ft.
.FRI...SW wind up to 20 kt. Seas 8 to 13 ft.
.FRI NIGHT...W wind 10 to 20 kt. Seas 8 to 11 ft.
.SAT THROUGH SUN...SW wind 10 to 25 kt. Seas 6 to 10 ft.
.MON...SE wind 20 to 30 kt. Seas 9 to 14 ft.

$$

PKZ414-141415-
Bering Sea Offshore East of 171W-
343 PM AKST Wed Dec 13 2023

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...NE wind 15 to 30 kt. Seas 8 to 13 ft. Freezing spray N of 56N.
.THU...E wind 20 to 35 kt. Seas 6 to 11 ft. Freezing spray N of 56N. Snow.
.THU NIGHT...SE wind 25 to 40 kt becoming SW 20 to 35 kt after
midnight. Seas 7 to 12 ft. Freezing spray N of 56N. Snow.
.FRI...SW wind 10 to 25 kt. Seas 7 to 11 ft.
.FRI NIGHT...SW wind 10 to 20 kt. Seas 5 to 10 ft.
.SAT THROUGH SUN...W wind 10 to 20 kt. Seas 7 to 11 ft.
.MON...SE wind 15 to 30 kt. Seas 6 to 10 ft.

$$

806 
FZAK62 PAFC 141218
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
318 AM AKST Thu Dec 14 2023

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.

PKZ499-150200-
318 AM AKST Thu Dec 14 2023
.SYNOPSIS FOR CENTRAL BERING SEA...

A Bering front located over the Central Aleutians continues 
eastward into Bristol Bay through early Fri. A developing 995 mb 
low near Adak Fri morning moves to 58N 173W at 984 mb by Sat 
morning.

$$

PKZ411-150200-
Bering Sea Offshore West of 180 and East of the International
Dateline-
318 AM AKST Thu Dec 14 2023

.TODAY...SW wind 15 to 25 kt. Seas 14 to 19 ft.
.TONIGHT...SW wind 15 to 25 kt. Seas 14 to 18 ft.
.FRI...SW wind 15 kt becoming SW 20 kt in the afternoon. Seas 14 ft.
.FRI NIGHT...SW wind up to 20 kt. Seas 12 ft.
.SAT...W wind up to 20 kt. Seas 7 to 12 ft.
.SUN...NE wind 15 to 30 kt. Seas 5 to 10 ft.
.MON...NE wind 20 to 35 kt. Seas 13 to 21 ft.

$$

PKZ412-150200-
Bering Sea Offshore 171W to 180 and North of 56N-
318 AM AKST Thu Dec 14 2023

...STORM WARNING TODAY...

.TODAY...SE wind 35 to 50 kt becoming SW 25 to 40 kt in the
afternoon. Seas 12 to 20 ft. Rain and snow.
.TONIGHT...W wind 15 to 30 kt. Seas 11 to 16 ft.
.FRI...SW wind 10 to 20 kt. Seas 9 to 14 ft.
.FRI NIGHT...W wind up to 20 kt. Seas 8 to 13 ft.
.SAT THROUGH SUN...NW wind up to 20 kt. Seas 6 to 11 ft.
.MON...E wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ413-150200-
Bering Sea Offshore 171W to 180 and South of 56N-
318 AM AKST Thu Dec 14 2023

...GALE WARNING TODAY...

.TODAY...SW wind 25 to 40 kt becoming W 15 to 25 kt in the
afternoon. Seas 10 to 16 ft. Rain.
.TONIGHT...SW wind 20 kt. Seas 9 to 13 ft.
.FRI...SW wind 10 to 25 kt. Seas 9 to 14 ft. Snow and rain showers.
.FRI NIGHT...W wind 20 kt. Seas 9 to 15 ft.
.SAT THROUGH SUN...W wind 10 to 20 kt. Seas 6 to 11 ft.
.MON...SE wind 15 to 30 kt. Seas 8 to 13 ft.

$$

PKZ414-150200-
Bering Sea Offshore East of 171W-
318 AM AKST Thu Dec 14 2023

...GALE WARNING THROUGH TONIGHT...

.TODAY...E wind 20 to 35 kt. Seas 6 to 11 ft. Freezing spray. Rain
and snow.
.TONIGHT...S wind 20 to 35 kt. Seas 7 to 12 ft. Freezing spray.
Rain and snow.
.FRI...SW wind 10 to 25 kt. Seas 8 to 11 ft.
.FRI NIGHT...SW wind 10 to 25 kt. Seas 8 to 13 ft.
.SAT THROUGH SUN...W wind 10 to 25 kt. Seas 9 to 14 ft.
.MON...SE wind 15 to 30 kt. Seas 6 to 11 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
442 PM AKST Mon Dec 11 2023

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

Bimodal weather exists on either side of the Prince William Sound
this afternoon, and will remain that way through Wednesday morning.
The high amplitude trough remains over Southcentral, with the
focus of the atmospheric river and warm sector of the trough over
the Central Chugach and Copper Valley. Meanwhile, on the western
side of the Sound, cold air advection and some instability has
lead to continued showers from the Kenai P. north into the Mat-Su.
A warm nose left over from last nights strong cross-barrier flow
has lead to some freezing rain and sleet over the western Kenai
and Anchorage, but this threat should end quickly this evening as
colder air returns. Expect showers to continue overnight for
these areas, with snow accumulation around a half inch possible.

The main focus of this forecast package in the short term is from
the Valdez area north into the Copper Valley. Low level warm air
has intruded well north into the Valley with southerly winds. This
has risen snow levels to approximately 1500 ft today, causing
difficult travel in the southern basin due to a combination of wet
snow, slush and rain falling onto frozen roadways. These snow
levels will slowly drop overnight as cold air moves in from the
west, returning conditions to snow in Valdez later this evening,
and to Chitina Tuesday morning. Precipitation rates will also
increase overnight again, resulting in heavy snow for the Copper
Valley and Valdez as a surface low moves south of Cordova. Models
finally decreased in their spread in low track, providing higher
confidence that a band of snow will also develop over the central
Copper Valley, extending north to Paxson. As the low moves inland,
precipitation rates will decrease Tuesday afternoon.

For many, the weather may seem like one long duration storm, but
the past 3-5 days have been the combination of many low pressure
systems moving into the Gulf in rapid succession. To continue
that theme, yet another low will in the southeastern Gulf Tuesday
afternoon will pivot north and west along the coast into the
Sound on Wednesday. This will bring another round of snow to
coastal areas, and provide higher chances for more light snow from
the western Kenai north to Anchorage and the Mat-Su. This system
is occluded, and should be comfortably snow.

-Jones

&&

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

The low that brought blizzard conditions to the Bristol Bay region
yesterday has become elongated across the Western Alaska Range
this evening. Moisture wrapping around the back side of the low
will contributed to continued light snow across portions of
Bristol Bay and the Lower Kuskokwim Valley tonight as the low
slowly pushes into Southcentral Alaska. Light snow will hold on
longest in the Lower Kuskokwim Valley, but gradually tapers off
through Tuesday as northerly flow brings colder, drier air into
the region.

The continuous northerly flow will have multiple effects. First,
northerly winds gusting to 40 mph will continue to lead to
blowing/drifting snow in the Kuskokwim Delta, despite no new
snowfall from Bethel west. Second, the cold air streaming across
the relatively warmer waters of the Bering Sea will continue to
produce snow showers for the Pribilof Islands, the Alaska
Peninsula, and the eastern Aleutian Islands. This will lead to
intermittent reductions in visibility as low as one quarter mile.
There is a lack of strong shortwaves which would lead to an
enhancement to steady snow and more prolonged periods of
visibility less than one mile. Finally, temperatures across
Southwest Alaska, broadly in the single digits above zero will
drop into the single digits below zero beginning Tuesday night
through at least Thursday. Combined with northerly winds across
the area, wind chills will hover between -20 and -30F.

Meanwhile out west, a compact low along a front moving into the
western Bering Sea this evening brings rain and a rain/snow mix to
the western Aleutians tonight. The low produces gales through
Tuesday morning until it weakens and dips south into the Pacific.

By Tuesday night, a storm force low tracks over the far western
Bering, pushing its front to the central Aleutians/Bering by
Wednesday night. This will bring a wedge of warm air across the
Aleutians, along with a changeover from snow back to rain. As the
front pushes east, it erodes high pressure over the central Bering
which has been aiding in drawing colder air southward. As a
result, northerly flow begins to weaken and winds diminish over
Southwest Alaska and the eastern Bering. This will reduce the
intensity of snow showers along the Alaska Peninsula and eastern
Aleutians, and reduce wind in the Kuskokwim Delta, which will
allow visibility to improve in these regions on Wednesday.

For Thursday, there is increasing uncertainty with the front
moving into the Pribilof Islands. Strong southeasterly winds may
combine with snow falling initially with the front to
significantly reduce visibility. However, a southeasterly wind
direction does not typically favor blowing snow with visibilities
of one half mile or less, and precipitation type may eventually
turn over to rain. With warming temperatures on Thursday, this
threat currently appears unlikely.

CQ

&&

.LONG TERM FORECAST (Days 4 through 7)...Friday through Monday...

The long-term forecast continues to feature general agreement on
the continuation of the active pattern Friday through at least
Monday. For Friday, a new deep upper trough drops into the
western/central Bering Sea while a shortwave ridge moves over the
eastern Bering and Southwest Alaska. The upper low that provided
Southcentral Alaska with very active weather in the short-term
continues to move eastward towards Southeast Alaska as the
shortwave ridge builds over Southcentral. However, any break in
weather associated with the ridge will not last long. Later on
Friday and into Saturday, the deep trough in the Bering moves
eastward and puts all of mainland Southern Alaska back in moist
southerly to southwesterly flow. A front over then central and
eastern Bering moves to the coast of Southwest later in the day on
Friday and eventually to Southcentral on Saturday. There is lots
of uncertainty exactly where a secondary low will spin up along
the front in the Gulf on Saturday. All ensemble and deterministic
guidance all show different solutions. However, generally
speaking, coastal Southcentral chances for moderate to heavy
precipitation are average. Southwest flow in the middle to upper
levels continues for Monday as additional shortwaves lift
northward through the Gulf and into Southcentral. The Bering Sea
and Aleutians stay active Saturday through Monday as shortwaves
pivot around the main trough. An additional low coming from
Kamchatka looks to send its gale-force front from the western
Aleutians Sunday afternoon to the central Aleutians by Monday
morning. This will spread gusty winds and precipitation across the
Aleutian Chain early next week.

&&

.AVIATION...

PANC...Expect a showery weather regime in Cook Inlet this evening
through Tuesday morning. There could be a rain/snow/Ice Pellets
shower at almost anytime, causing a brief reduction in ceiling/vis.
However, the most likely time to see snow showers will be between
06Z and 15Z out ahead of an upper low/trough lifting northward up
Cook Inlet. Mixed precipitation showers will transition to all snow
showers later this evening. MVFR conditions are most likely in
snow showers, but conditions could briefly drop as low as IFR.
Conditions will improve during the morning hours on Tuesday, with
dry conditions and VFR ceilings likely until snow with the next
storm arrives sometime Tuesday night.

As for winds, southerly winds will prevail this evening. They
will mostly be less than 10 kts, but there could be a few gusts as
showers move through. Winds will lighten and shift around to
northerly Tuesday morning in response to a low moving into the
Gulf.

&&