Storm Warning 166, NWS Anchorage, AK

854 
FZAK61 PAFC 250013
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
313 PM AKST Sat Dec 24 2022

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-251430-
313 PM AKST Sat Dec 24 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 984 mb low near 59N 145W dissipates over the northern Gulf Sat 
night. A 960 mb N Pacific low this evening strengthens to 950 mb 
near 55N 150W Sun evening, before weakening to 962 mb near 58N 
151W Mon evening.


$$

PKZ351-251430-
Gulf of Alaska Offshore North of 57N and West of 144W-
313 PM AKST Sat Dec 24 2022

...STORM WARNING SUNDAY AND SUNDAY NIGHT...

.TONIGHT...NE wind up to 15 kt becoming E 10 to 25 kt after
midnight. Seas 7 to 11 ft.
.SUN...E wind 30 to 40 kt increasing to 40 to 50 kt in the
afternoon. Seas 9 to 16 ft building to 18 to 26 ft in the
afternoon. Rain.
.SUN NIGHT...E wind 40 to 50 kt diminishing to 30 to 45 kt after
midnight. Seas 25 to 30 ft. Rain.
.MON...SE wind 25 to 40 kt. Seas 20 to 30 ft.
.MON NIGHT...S wind 15 to 25 kt. Seas 15 to 21 ft.
.TUE THROUGH THU...SE wind 20 to 35 kt. Seas 9 to 17 ft.

$$

PKZ352-251430-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
313 PM AKST Sat Dec 24 2022

...GALE WARNING SUNDAY AND SUNDAY NIGHT...

.TONIGHT...E wind up to 20 kt increasing to 15 to 30 kt after
midnight. Seas 7 to 11 ft.
.SUN...E wind 30 to 45 kt. Seas 13 to 20 ft building to 20 to 24 ft 
in the afternoon. Rain.
.SUN NIGHT...SE wind 30 to 45 kt. Seas 18 to 31 ft. Rain.
.MON...S wind 15 to 30 kt. Seas 19 to 26 ft.
.MON NIGHT...SW wind 20 to 30 kt. Seas 15 to 21 ft.
.TUE THROUGH THU...SE wind 20 to 35 kt. Seas 10 to 18 ft.

$$

106 
FZAK61 PAFC 251242
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
342 AM AKST Sun Dec 25 2022

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-260145-
342 AM AKST Sun Dec 25 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 952 mb N Pacific low at 50N 150W strengthens to 949 mb near 53N
148W Sun evening. This low will weaken to 956 mb Mon morning near  
57N 150W Mon morning. This low will weaken to 975mb Tuesday
morning and be near 59N 151W.

$$

PKZ351-260145-
Gulf of Alaska Offshore North of 57N and West of 144W-
342 AM AKST Sun Dec 25 2022

...STORM WARNING TODAY...

.TODAY...E wind 30 to 40 kt increasing to 50 kt in the afternoon.
Seas 10 to 15 ft building to 18 to 25 ft in the afternoon. Rain.
.TONIGHT...E wind 30 to 45 kt. Seas 22 to 28 ft. Rain.
.MON...S wind 20 to 35 kt. Seas 18 to 28 ft.
.MON NIGHT...SW wind 15 to 25 kt. Seas 14 to 20 ft.
.TUE...SW wind 15 to 30 kt. Seas 9 to 14 ft.
.WED...S wind 20 to 35 kt. Seas 7 to 12 ft.
.THU...SE wind 20 to 30 kt. Seas 12 to 16 ft.

$$

PKZ352-260145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
342 AM AKST Sun Dec 25 2022

...GALE WARNING THROUGH MONDAY...

.TODAY...E wind 30 to 45 kt. Seas 12 to 20 ft building to 19 to
22 ft in the afternoon. Rain.
.TONIGHT...SE wind 25 to 40 kt. Seas 16 to 28 ft. Rain.
.MON...SW wind 20 to 35 kt. Seas 18 to 24 ft.
.MON NIGHT...SW wind 20 to 30 kt. Seas 14 to 19 ft.
.TUE...W wind 15 to 30 kt. Seas 9 to 14 ft.
.WED...SE wind 20 to 35 kt. Seas 8 to 13 ft.
.THU...SE wind 10 to 25 kt. Seas 13 to 16 ft.

$$

837 
FZAK61 PAFC 260016
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
316 PM AKST Sun Dec 25 2022

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-261400-
316 PM AKST Sun Dec 25 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 950 mb low near 54N 148W moves to 58N 151W while weakening to 
966 mb Mon afternoon. It then moves to 59N 149W at 984 mb by Tue 
afternoon.

$$

PKZ351-261400-
Gulf of Alaska Offshore North of 57N and West of 144W-
316 PM AKST Sun Dec 25 2022

...GALE WARNING TONIGHT...

.TONIGHT...E wind 30 to 45 kt. Seas 17 to 32 ft. Rain.
.MON...S wind 15 to 30 kt. Seas 19 to 33 ft.
.MON NIGHT...SW wind 15 to 30 kt. Seas 14 to 20 ft.
.TUE...SW wind 10 to 25 kt. Seas 10 to 14 ft.
.TUE NIGHT...SW wind 10 to 20 kt. Seas 6 to 11 ft.
.WED...SE wind 20 to 35 kt. Seas 7 to 12 ft.
.THU THROUGH FRI...S wind 15 to 30 kt. Seas 12 to 16 ft.

$$

PKZ352-261400-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
316 PM AKST Sun Dec 25 2022

...GALE WARNING THROUGH MONDAY...

.TONIGHT...SE wind 20 to 35 kt. Seas 14 to 22 ft. Rain.
.MON...SW wind 20 to 35 kt. Seas 18 to 27 ft.
.MON NIGHT...SW wind 20 to 30 kt. Seas 15 to 19 ft.
.TUE...W wind 15 to 30 kt. Seas 10 to 15 ft.
.TUE NIGHT...SW wind 10 to 25 kt. Seas 8 to 12 ft.
.WED THROUGH FRI...SW wind 20 to 35 kt. Seas 9 to 16 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
432 PM AKST Fri Dec 23 2022

.ANALYSIS AND UPPER LEVELS...

A Rex Blocking pattern currently extends across the North Pacific
with low pressure south of the Aleutians and high pressure
extending from Siberia to across the Alaskan mainland.

Closer to the surface, observations show strong northeasterly flow
across Southcentral. The strongest winds have been observed in the
Matanuska Valley where the strongest gusts have been near 70 mph.
Gusts near 60 mph occurred at Ted Stevens International Airport.
Radar shows little to no shower activity across the area.

&&

.MODEL DISCUSSION...

Forecast confidence remains low overall except for the immediate
short term forecast. There is good agreement with the overall
trend for strong winds across Southcentral to ease over the next
several hours. However, model agreement has diverged since
yesterday's runs with respect to a low moving across the Alaska
Peninsula on Saturday. This means there is very low confidence
with respect to the snowfall forecast for Kodiak and across
Southwest Alaska.

&&

.AVIATION...
PANC...VFR conditions will persist for this TAF period. Winds will
gradually ease during the afternoon and evening hours across the
area.

&&

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

The upper level trough and associated cold air advection which
produced strong winds and blowing snow across portions of
Southcentral today has exited to Southwest Alaska. However, low
pressure down over the Gulf of Alaska will maintain very tight
pressure gradients. Low level flow behind the upper trough will
also be slow to slacken. As a result, expect winds to linger
tonight into Saturday, especially through mountain passes/valleys.
Have extended the Blizzard Warning for the Matanuska Valley all
the way through Saturday morning at which point winds should
significantly diminish. Gusty winds and blowing snow will also
linger along Knik Arm and the Glenn Highway Corridor down into
north to west Anchorage.

A more aggressive digging of the upper level trough is leading to
a change in track of the low currently over the southern Gulf. It
will remain over the eastern half of the Gulf as it track
northward tonight and Saturday, leading to a much slower arrival
of snow for the Copper River Basin and Valdez/Cordova areas. Now
expect light snow to arrive in the far southeastern Copper River
Basin overnight tonight then spread slowly westward across the
Copper River Basin and eastern Prince William Sound on Saturday.
The western extent of snow on saturday is very much in question,
but it is looking less and less likely that the eastern Kenai
Peninsula will see much, if any snow, from this system.

Meanwhile, a separate surface trough tracking westward across the
Gulf will reach Kodiak Island late tonight through Saturday.
Expect mesoscale bands of snow with this trough, which makes it
difficult to nail down snowfall accumulation for any given
location. Do expect all of Kodiak Island to see some light
accumulation. There will also be some stronger gusty winds with
this which could briefly reduce visibilities to around one half
mile at times. The trough and associated snow will dissipate by
late Saturday.

As we continue to Christmas Day and beyond, all attention will
shift to a large deep low tracking into the Gulf from the
Northeast Pacific. A strong occluded front out ahead of the low
will reach the Gulf coast/Kodiak by late Sunday, bringing
widespread gale to storm force winds across the Gulf coastal
waters along with moderate to heavy precipitation along much of
the coastal zone. Prevailing low level easterly flow will lead to
upslope flow and enhanced precipitation amounts across the eastern
Kenai Peninsula Mountains. Much warmer air will also accompany the
front leading to a fairly quick transition from snow to rain for
areas along the coast near sea level. Snow levels for coastal
mountains will quickly rise Sunday afternoon/evening, reaching
1000 feet or higher. Precipitation will linger along the coast all
the way through Monday. While some moisture will attempt to cross
over the coastal mountains, dry and cold air inland will make it
difficult to saturate the low levels of the atmosphere. As a
result, inland areas of Southcentral look to remain dry with
slowly warming temperatures as we head to the beginning of next
week.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: This
afternoon through Monday afternoon )...

Conditions have largely quieted down for the Alaska Peninsula
(AKPEN) although scattered rain showers linger around the
southern AKPEN as weak low pressure continues to move westward in
the North Pacific. A strong shortwave ejecting from an upper
trough across Yukon, Canada continues to advance westward towards
Bristol Bay this afternoon and through the evening. This will
bring cold temperatures and continued offshore flow to mainland
Southwestern Alaska. Windchills are expected to be quite low this
evening due to the winds in conjunction with the cold air
advection as the closed upper low continues westward towards the
eastern Bering Sea. In response, a Windchill Advisory is in effect
from this until Saturday afternoon.

Meanwhile, a surface low is expected to develop around the
northern AKPEN very early Saturday morning. There is uncertainty
with the exact track as guidance continues to struggle with how to
handle the surface feature. Another level of uncertainty is
pinpointing exactly where mesoscale banding will set up along the
AKPEN Saturday morning through evening, in addition to how far
north into the Southwest mainland the precipitation reaches. The
current thinking now is that the AKPEN will see precipitation
mostly in the form of snow, while coastal sections of Bristol Bay
and the Kuskokwim Delta will see less snow. Precipitation winds
down for coastal Southwest overnight Saturday, while easterly to
southeasterly upslope flow keeps the North Pacific side of the
AKPEN unsettled through Sunday morning. A strong North Pacific low
and its front approach Sunday afternoon through Monday afternoon
as rain/snow mix is likely for the AKPEN, while mostly snow is
expected for the western interior sections of Bristol Bay. Most
accumulation is confined to the mountains. Please stay tuned to
additional forecast updates as details continue to be fine-tuned
in both the near-term and short-term during this complex weather
pattern.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3: This
afternoon through Monday afternoon)...

Active weather will continue for the Bering Sea and Aleutians
during the short-term period. Scattered snow showers continue to
taper off for the Pribilofs tonight as a frontal system continues
to push westward across the Bering and the rest of the Aleutian
Chain Saturday morning through the afternoon, bringing an
additional band of rain/snow showers exiting the western Chain
Saturday evening.

Back east, a surface low is expected to develop across the Alaska
Peninsula early Saturday morning in response to a strong closed
upper low moving westward across Southwestern Alaska and into the
eastern Bering Sea. There is still lots of uncertainty with this
feature as guidance continues to struggle with the evolution of
the system. Uncertainty is especially heightened for the Pribilof
Islands for Sunday. Snow looks to be the dominant precipitation
type as the system will be dragging cold air with it from mainland
Alaska. The ultimate track of the surface feature will determine
how much snow and how windy the Pribilofs get for Sunday. Some
guidance has the system tracking a little more north of the
Pribilofs, while some guidance also depicts the system taking a
more southern track which would be more favorable for higher winds
and more snowfall. The system then continues westward through the
Bering during Sunday afternoon into the evening before making a
southern turn to the North Pacific while crossing the central
Chain through the day on Monday. Snow amounts appear to be light
for the Aleutians overall, with most accumulation confined to the
mountains. Please check back for the latest forecast updates as
finer details on evolution and track continue to be fine-tuned for
the surface low pressure system expected to traverse the eastern
and central Bering Sea.

$$.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)...

The latest operational model runs and ensemble means seem to be
in a decent agreement with an upper level low over the western
Bering Sea near Adak, and high pressure remaining over Siberia.
While the upper low sits nearly stationary between Tuesday and
Wednesday, a series of North Pacific systems rotates around the
low, moving north-northeastward past the Aleutians and into the
Gulf of Alaska. This will bring an unsettled pattern for all of
the coastal areas of Southcentral heading into late next week.
While specific details still need to ironed out, persistent
onshore flow will favor moderate to heavy precipitation for the
coast, with much of the mainland remaining relatively dry during
the period. A general troughing pattern out west will result in a
wet pattern for much of the Bering Sea and Aleutians. Cold,
northerly flow over the relatively warm waters will also help
generate widespread showers over the Pribilof Islands and along
the Aleutian Chain.

&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard Warning: 111, 131.
         Wind Chill Advisory: 141, 152.
MARINE...Storm Warning: 130.
         Gale Warning: 119, 120, 125, 127-128, 130, 138-140, 160,
         179-181, 185, 351, 411-414.
         Heavy Freezing Spray: 127-128, 139-140, 160, 179-181,
         185, 412, 414
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...ED
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DN
LONG TERM...MF