Gale Warning 124, NWS Anchorage, AK

704 
FZAK61 PAFC 171238
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
338 AM AKST Thu Feb 17 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.

PKZ399-180200-
338 AM AKST Thu Feb 17 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A series of weak low centers moves over the Northern Gulf through
Fri afternoon. A front moves across the Gulf for Fri afternoon.

$$

PKZ351-180200-
Gulf of Alaska Offshore North of 57N and West of 144W-
338 AM AKST Thu Feb 17 2022

.TONIGHT...SW wind 25 kt. Seas 12 ft.
.THU...SW wind 15 kt becoming 10 to 25 kt in the afternoon. Seas
10 ft.
.THU NIGHT...S wind 20 to 30 kt. Seas 9 to 12 ft.
.FRI...SW wind 25 to 35 kt. Seas 11 to 14 ft.
.FRI NIGHT...W wind 20 to 30 kt. Seas 10 to 15 ft.
.SAT THROUGH MON...SW wind 15 to 30 kt. Seas 7 to 12 ft.

$$

PKZ352-180200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
338 AM AKST Thu Feb 17 2022

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...SW wind 10 to 20 kt. Seas 11 ft.
.THU...SW wind 10 to 20 kt increasing to 15 to 30 kt in the
afternoon. Seas 10 ft.
.THU NIGHT...S wind 20 to 30 kt becoming SW 35 kt after midnight.
Seas 9 to 13 ft.
.FRI...SW wind 25 to 35 kt. Seas 13 ft.
.FRI NIGHT...W wind 20 to 30 kt. Seas 13 ft.
.SAT THROUGH MON...SW wind 15 to 30 kt. Seas 8 to 13 ft.

$$

064 
FZAK61 PAFC 171239
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
339 AM AKST Thu Feb 17 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.

PKZ399-180130-
339 AM AKST Thu Feb 17 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A series of weak low centers move across the Northern Gulf 
through Fri afternoon. A front moves across the Gulf for Fri 
afternoon.

$$

PKZ351-180130-
Gulf of Alaska Offshore North of 57N and West of 144W-
339 AM AKST Thu Feb 17 2022

.TODAY...SW wind 10 to 20 kt. Seas 9 ft.
.TONIGHT...S wind 15 to 30 kt. Seas 8 to 11 ft. Rain.
.FRI...W wind 30 kt. Seas 10 to 14 ft.
.FRI NIGHT...W wind 20 to 30 kt. Seas 11 to 14 ft.
.SAT THROUGH SUN...W wind 15 to 30 kt. Seas 7 to 12 ft.
.MON...S wind 20 kt. Seas 7 ft.

$$

PKZ352-180130-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
339 AM AKST Thu Feb 17 2022

.TODAY...SW wind up to 15 kt increasing to 10 to 25 kt in the
afternoon. Seas 9 ft.
.TONIGHT...S wind 15 to 25 kt becoming SW 30 kt after midnight.
Seas 9 to 12 ft. Rain.
.FRI...SW wind 20 to 30 kt. Seas 13 ft.
.FRI NIGHT...W wind 20 to 30 kt. Seas 13 ft.
.SAT THROUGH SUN...SW wind 15 to 30 kt. Seas 8 to 13 ft.
.MON...S wind 20 kt. Seas 8 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
554 AM AKST Wed Feb 16 2022

.ANALYSIS AND UPPER LEVELS...

A large low pressure system near 49N 180E is moving
northeastward. A second low pressure system continues to move
northeastward across the Kuskokwim Delta. A broad upper level
ridge currently extends northward from the east Pacific to the
Copper Basin. Plumes of moisture continue to move along the outer
edge of this ridge and over Southcentral Alaska.

Closer to the surface, radar shows snow moving northeastward
across both Southcentral and Southwest Alaska. Observations show a
mix of precipitation types across the area. Generally speaking,
the most mixing is occuring across lower lying coastal locations
while higher elevations and more inland locations are experiencing
all snow.

&&

.MODEL DISCUSSION...

Models are in good agreement with respect to the placement and
intensity of the aforementioned large North Pacific low that is
moving northeastward into the Bering Sea. One area where models
are struggling is with respect to the development and propagation
of a second low that is forecast to develop near the western
Alaska Peninsula and move northeastward. There are differences in
the potential tracks of this system which will result in
differences in the temperature forecast and ultimately the
precipitation type forecast. A more inland and northern track will
allow for warmer temperatures across Southcentral and thus a
greater chance of a snow/rain/mixed precipitation event for the
area. A more southerly track will favor colder temperatures and
snow being the dominant precipitation type to fall across the
area.

&&

.AVIATION...
PANC...Conditions will fluctuate between IFR and LIFR as ceilings
range between 1500ft and 400ft while visibility remains between
1SM and 4SM. Snow and freezing rain is likely before 16th/13z,
then southeasterly Turnagain Arm winds will begin at 16th/18z and
continue through 16th/21z. These stronger winds will also allow
for warmer temperatures and a change over to all rain through
16th/21z. Temperatures will cool after 16th/21z and thus
precipitation will change over to a rain snow mix. Finally,
freezing drizzle and snow is expected after 17th/06z.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2:
Today through Thursday night)...

Active weather continues across Southcentral. An upper level
ridge in place over the Gulf of Alaska continues to steer several
upper level waves across Southcentral from west to east. A low
center lifting inland over Southwest Alaska this morning extends a
front eastward over Southcentral. This system has ample moist
southerly flow, allowing temperatures to warm as the front pushes
inland. Precipitation type remains the greatest challenge
throughout the day today. To complicate matters across the
Anchorage Bowl and Mat-Su, gusty southeasterly winds are expected
to ramp up through Turnagain Arm and Knik River Valley late this
morning, leading to warming temperatures and a change in
precipitation from snow to rain.

Meanwhile across the Susitna Valley and northern Copper River
Basin, precipitation is expected to remain all snow. One change to
the forecast package was issuance of a Winter Weather Advisory for
the northern Copper River Basin, where snow may fall heavily at
times throughout the day today. A second upper level wave passes
across Southcentral later this afternoon, which will enhance
precipitation especially in places like Susitna Valley and the
northern Copper River Basin.

As this system exits to the east, residual showers will linger
through the evening hours and possibly into early Thursday
morning especially for Susitna Valley and northern Copper River
Basin. Then all attention shifts to the next (third) system this
week arriving Thursday afternoon. There are several differences
between model solutions with this next low, so confidence remains
low however it is looking to take a similar track from west to
east across Southcentral. Precipitation type with this next
system will be a challenge once again, as warm southerly flow
accompanies this low. One uncertain detail includes how far south
or north the low tracks, as this will drive differences in
temperatures, and thus precipitation types, across Southcentral.
Similar to today's low, this next low will move through rather
quickly, exiting Southcentral to the east by Friday morning.
Please stay tuned and check back frequently for updates as we
continue to refine the forecast.

&&

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

A busy pattern persists for Southwest Alaska through Saturday. An
eastern Bering surface low and its front will gradually weaken as
the system moves inland today into Thursday. With this system, a
Winter Weather Advisory remains in effect until noon today for the
lower Kuskokwim Valley for additional snowfall and accumulations.
The greatest snowfall rates are expected to occur before 7am this
morning. Another Winter Weather Advisory also remains in effect
until 9am this morning for the Kuskokwim Delta for possible
blowing snow.

A brief period of calmer weather is expected across the region
from tonight into early Thursday morning as a ridge builds from
west to east behind the weakening low and in front of the next
upcoming system. Later Thursday morning, a front extending from an
occluding Bering Sea surface low will push eastward into
Southwest. Precipitation is expected to be mainly rain with a
rain/snow mix possible at times, although north of the Kuskokwim
River, temperatures look to stay cold enough for all precipitation
to remain snow. There will be a very brief break in precipitation
as the front moves inland and the low itself tracks into
Southwest Friday morning. Cold air wrapping around the backside of
the low will transition rain to snow starting later Friday and
into Saturday. Yet another front will push eastward into Southwest
later on Saturday. However, models are currently struggling with
the timing of the front, so there are many remaining details to be
ironed out with this system.

&&

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

A busy pattern also persists for the Aleutians and Bering through
Saturday. A surface low near the western Aleutians will extend its
front from west to east across the Bering Sea today as the system
progresses northeastward. The front will bring rain and small
craft winds to the western and central Aleutians and southern
Bering through this afternoon, but small crafts will be followed
by gales as the low itself continues its track into the central
Bering through Friday morning. The low will gradually weaken into
Saturday as it moves east towards Southwest. On Friday, a ridge
builds behind the low and from west to east across the entire
domain, and this will bring a brief period of calmer weather
before the next system arrives. By Friday afternoon, another
North Pacific surface low moves over the western Aleutians, and
its front will extend across the entire Bering as is pushes
northeastward. Another round of gales and widespread rain is
expected across most of the Bering and Aleutians for Saturday with
this system.

&&

.Marine (Days 3 through 5: Wednesday through Friday)...

Gulf of Alaska:

A front pushes into the Gulf Wednesday morning, bringing
widespread southerly small craft winds, 10 to 15 ft seas, and rain.
Winds largely diminish below small crafts, waves decrease below
10 ft, and rain peters off around Thursday morning. Uncertainty
increases Thursday evening regarding the track and strength of an
incoming North Pacific low and its front. Winds will likely
increase to small crafts between Thursday evening and Friday as
the front tracks through the Gulf. However, the extent and
duration of small craft winds, as well as the potential for gales,
is difficult to determine at this time. Precipitation associated
with this front will likely fall as rain or rain/snow mix. By late
Friday evening, the low looks to move over the Northern Gulf,
bringing the potential for gusty, westerly gap winds and freezing
spray. Rain and rain/snow mix will transition to snow showers.

Bering Sea/Aleutians:

A busy pattern persists for the Bering and Aleutians through
Friday. On Wednesday, small craft winds and seas approaching 20 ft
are expected near the Eastern Aleutians as a surface low moves
from the North Pacific into Bristol Bay. Further west, a strong
North Pacific low tracks along the Aleutians Wednesday morning
through Friday. Rain or rain/snow mix falling ahead of the low
will transition into snow showers behind it. The low weakens
quickly, so while widespread small crafts are expected, gales will
be limited mostly to the Northern Bering and south of the
Aleutians. Seas 15 to 25 ft are expected near the low, with seas 8
to 15 ft elsewhere. There is some uncertainty as this low
interacts with a compact low moving across the Eastern Aleutians
and into Southwest Alaska on Thursday. However, both systems look
to remain fairly weak as they interact, with winds remaining small
crafts or lower. On Friday, yet another low pushes its front west
towards the Central Aleutians, bringing a broad swath of gales
and rain.

&&

.Long Term Discussion (Days 4 through 7: Thursday through
Sunday)...

An occluding North Pacific low tracks along the Aleutians from
Thursday through Friday evening. A triple point low forms near the
Eastern Aleutians Thursday morning, introducing uncertainty as
these two features interact. The EC suggests that the triple point
low will be absorbed into the occluding low, while the GFS and
GEM suggest that the two surface lows will rotate around each
other. How these lows interact has implications for winds and
precipitation. For example, the GFS brings the compact low
further north into the Kuskokwim Delta and Bristol Bay on
Thursday, suggesting greater snow amounts in those areas as
compared to the GEM. As the GFS brings the low further north, it
brings an increased potential for rain along Southern Bristol Bay
due to greater warm air intrusion inland. In contrast, the GEM
brings the compact low straight towards the Prince William Sound,
suggesting greater snow amounts along the North Gulf coast from
Thursday afternoon through Friday evening as compared to the GFS.
With winds, the GEM's stronger North Gulf low suggests that gap
winds will approach storm force early Saturday morning, as
compared to winds below small crafts with the GFS and EC.
Overall, details remain uncertain at this time for the front
tracking across southern Alaska from Thursday morning through
Friday, as well as for the various surface lows.

As this strong system moves across southern Alaska Thursday
through Friday, a ridge builds behind it. This heralds a brief
return to calmer weather and colder conditions through most of
Saturday. However, unsettled conditions resume as a strong low
near the Western Aleutians pushes its front across the Bering. The
front reaches Southwest Alaska late Saturday night into Sunday
morning. Confidence decreases at this point due to poor model
agreement. While details are uncertain, the position of the upper
level longwave trough over Alaska suggests that unsettled weather
is likely.

&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 101, 111, 121, 141, 145, 152, 155.
MARINE...Gale Warning 130, 160, 165, 175, 176, 177, 180, 185, 411, 412.
Heavy Freezing Spray Warning 130, 185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...ED
SOUTHCENTRAL ALASKA...KO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...AF
MARINE/LONG TERM...MK/KM