Storm Warning 67, NWS Anchorage, AK

532 
FZAK62 PAFC 201148
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
348 AM AKDT Mon Mar 20 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.

PKZ499-210045-
348 AM AKDT Mon Mar 20 2023
.SYNOPSIS FOR CENTRAL BERING SEA...

A 956 mb low at 62N 174W this morning will move into eastern
Siberia this afternoon. A second 988 mb low at 54N 175E this
afternoon will move to 56N 168W at 987 mb Tuesday morning. This
low then exits into the Gulf Wednesday morning. 

$$

PKZ411-210045-
Bering Sea Offshore West of 180 and East of the International
Dateline-
348 AM AKDT Mon Mar 20 2023

...GALE WARNING TODAY AND TUESDAY...

.TODAY...W wind 20 to 35 kt. Seas 12 to 20 ft.
.TONIGHT...NW wind 10 to 25 kt increasing to 20 to 30 kt after
midnight. Seas 11 to 14 ft.
.TUE...W wind 25 to 40 kt. Seas 13 to 18 ft. Freezing spray N of 58N. 
.TUE NIGHT...W wind 25 to 40 kt. Seas 12 to 20 ft.
.WED THROUGH THU...SW wind 15 to 30 kt. Seas 7 to 12 ft.
.FRI...S wind 25 to 40 kt. Seas 11 to 19 ft.

$$

PKZ412-210045-
Bering Sea Offshore 171W to 180 and North of 56N-
348 AM AKDT Mon Mar 20 2023

...STORM WARNING TODAY...

.TODAY...W wind 35 to 50 kt diminishing to 25 to 40 kt in the
afternoon. Gusts to 65 kt in the morning. Seas 18 to 33 ft.
.TONIGHT...W wind 15 to 30 kt. Seas 12 to 20 ft.
.TUE...NW wind 20 to 35 kt. Seas 12 to 15 ft.
.TUE NIGHT...W wind 25 to 40 kt. Seas 12 to 20 ft.
.WED THROUGH THU...W wind 20 to 35 kt. Seas 9 to 17 ft.
.FRI...S wind 25 to 40 kt. Seas 8 to 13 ft.

$$

PKZ413-210045-
Bering Sea Offshore 171W to 180 and South of 56N-
348 AM AKDT Mon Mar 20 2023

...GALE WARNING TODAY AND TUESDAY...

.TODAY...W wind 30 to 45 kt becoming SW 15 to 30 kt in the
afternoon. Seas 15 to 30 ft.
.TONIGHT...W wind 15 to 30 kt. Seas 13 to 17 ft. Snow and rain.
.TUE...NW wind 25 to 35 kt. Seas 14 to 17 ft.
.TUE NIGHT...W wind 25 to 35 kt. Seas 15 to 20 ft.
.WED...W wind 20 to 35 kt. Seas 11 to 19 ft.
.THU...SW wind 10 to 25 kt. Seas 6 to 11 ft.
.FRI...S wind 20 to 35 kt. Seas 7 to 12 ft.

$$

PKZ414-210045-
Bering Sea Offshore East of 171W-
348 AM AKDT Mon Mar 20 2023

...STORM WARNING TODAY...

.TODAY...SW wind 35 to 50 kt diminishing to 30 to 40 kt in the
afternoon. Seas 10 to 18 ft.
.TONIGHT...SW wind 15 to 30 kt. Seas 7 to 12 ft. Snow.
.TUE...SW wind 10 to 25 kt becoming NW 20 to 35 kt in the
afternoon. Seas 6 to 11 ft. Snow.
.TUE NIGHT...NW wind 20 to 35 kt. Seas 6 to 11 ft.
.WED THROUGH FRI...SW wind 20 to 35 kt. Seas 6 to 11 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
532 AM AKDT Sun Mar 19 2023

.ANALYSIS AND UPPER LEVELS...

A few weak mesolows will move across the Gulf of Alaska over the
next couple of days, but most of the active weather for
Southcentral has settled. Attention shifts westward with the
approach of a strong North Pacific low entering the Bering Sea
today. The low is set to cross into the western Bering Sea today,
with the core of strongest winds passing over the Western
Aleutians. The system will quickly move northeastward and into the
Bering Strait through Monday evening. The associated front moves
into Southwest Alaska on Monday, with a second trough extending
towards the Western Aleutians. The models are hinting at a
secondary surface low developing at the base of the second trough
on Monday afternoon.

&&

.MODEL DISCUSSION...

Models are in good overall agreement through the short term. A
couple of weak surface lows move across the Gulf of Alaska towards
the Kenai Peninsula and there is some uncertainty regarding
precipitation between Seward and Portage.

&&

.AVIATION...
PANC...VFR conditions will persist. Southerly winds will continue
through the day and will remain gusty through mid-morning.

&&

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

The second of the two large lows that tracked between Kodiak and
the Kenai Peninsula the past two days has now moved west of the
Aleutian Range. Strong southeasterly flow is still pushing some
snow showers into the Kenai Peninsula early this morning, but
these should taper off throughout the day. The biggest uncertainty
in today's forecast is in regards to a small low that is entering
the southern Gulf and tracking toward the Kenai Peninsula. This
low is small and does not have the upper level support the
previous two lows did. Models are rapidly weakening it as it moves
northward, but it is moving northward a little faster than models
had it. There are also no observations near it especially with
all the buoys in the Gulf of Alaska offshore area inoperable as a
result of the numerous winter storms. This low should weaken and
bring minimal additional snow shower activity to the eastern Kenai
Peninsula and/or Kachemak Bay this afternoon and evening, but we
will need to keep an eye on it.

A large low in the Bering Sea will send a front into Southcentral
Monday and Monday night. It will bring some rain and snow to
Kodiak Monday and into Monday night. The big question for most of
Southcentral with this front is where exactly a triple point low
develops northeast of Kodiak Island Monday night. This will be a
factor in precipitation over the Kenai Peninsula and Prince
William Sound regions as well as winds in Anchorage and the
Matanuska Valley. Some of the higher resolution models are
bringing in gusty southeasterly winds to Anchorage and the
Matanuska Valley for Tuesday which would send temperatures up to
around 40 degrees for a high. Should the winds stay more northerly
it would keep the temperatures a bit cooler. At this time the
southeast winds look to be more likely than not.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today
through Tuesday night)...

A low centered over interior Bristol Bay will weaken and track
back toward the western Gulf of Alaska through the day today.
Light snow overspreading the region will decrease in intensity
through the morning hours, with the westernmost extent of snowfall
expected along a line from Dillingham north to Aniak. Blowing snow
will be a brief risk for the next few hours, particularly near
Koliganek and New Stuyahok before winds diminish and snow tapers
off through midday. This will give way to some breaks of sun and
another day with high temperatures reaching into the 30s for much
of Bristol Bay and the Lower Kuskokwim Valley.

Then, a strong Bering Sea low pushes a front to the Kuskokwim
Delta coast, bringing gale force winds and moderate snow by this
evening. A Winter Weather Advisory is in effect for the threat of
blowing snow along the coast caused by the arrival of this front.
The front will push eastward overnight and through the morning
hours on Monday, bringing several inches of snow to the Kuskokwim
Delta. Temperatures are expected to warm quickly with the frontal
passage as winds turn southerly and eventually southwesterly. In
addition, snow will turn showery, and this combination will lead
to the end of any risk of low visibility due to blowing snow
despite continued gusty winds on Monday. As the front pushes into
Bristol Bay, winds are expected to be weaker and temperatures are
expected to be warmer, suggesting that blowing snow is not likely
to be an issue. The area, though, will see a few inches of snow
accumulation. Winds will begin to diminish Monday night as the low
exits to the Bering Strait, and snow showers taper off in tandem.
A third system crosses the Alaska Peninsula on Tuesday, bringing
another round of light snow to parts of Southwest Alaska.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3: Today
through Tuesday night)...

A deepening low in the North Pacific will move across the western
Aleutians today, bringing high winds to Shemya as a corridor of
hurricane force winds passes through the islands on the south side
of the low. Strong cold air advection wrapping around the deepening
low and rapid pressure rises as the low tracks into the Bering
Sea will support strong winds there this afternoon and evening.
Seas associated with this swath of strong winds could build to as
high as 40 feet. Adak is expected to stay out of the strongest
corridor of winds as the low moves into the Bering Sea, but the
current forecast calls for gusts to peak at 70 mph late this
evening. The low is then expected to track with high confidence
into the northern Bering through Monday. This will then place the
Pribilof Islands within the strongest winds. While these winds
will have diminished somewhat by this point, southwesterly winds
as gusting to 75 mph are expected on Saint Paul Island early
Monday morning. This has prompted the issuance of another High
Wind Warning for the islands. The low will then begin to weaken as
it tracks into the Bering Strait Monday night, with its associated
winds diminishing to gale force. A second, weaker low will then
track along the Aleutian Islands, bringing gale force westerly winds
Monday and Tuesday. The low enters the western Gulf Tuesday night
and cold northwesterly flow sets up across the Bering Sea in its
wake.

&&

.LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)

Active weather looks to continue through the Gulf of Alaska and
coastal Southcentral Alaska through the long-term period. A deep
negatively tilted trough extends southeastward from Siberia,
through Southwest Alaska and the Alaska Peninsula, and into the
North Pacific. Guidance is still in disagreement with strength and
positioning regarding the resultant surface low in the Gulf. The
12z GFS is the strongest of the guidance and the most south with
positioning in the extreme southwestern Gulf on Wednesday. The 12z
Canadian is a middle-ground between the stronger GFS and the
weaker 12z ECMWF. the Canadian and ECMWF guidance have the low in
the vicinity of Kodiak Island. Regardless, it appears that Kodiak
Island, as well as the eastern Kenai Peninsula, Prince William
Sound, and the northern Gulf Coast will see the best chance at
amplified precipitation both from the direct influence of the low
and from its front as it moves north to coast Wednesday through
Thursday. Gale-force winds with potentially storm-force gusts will
be a good bet for the southwestern to south-central Gulf as the
system pulls away to the east Thursday. Another shortwave looks to
approach Southcentral and the Gulf from northwest Friday into
Saturday. However, confidence during this timeframe is extremely
low due to many disagreements in strength and positioning/track of
a potential low pressure system that could develop in the
vicinity of Prince William Sound Friday. However, with north to
northwesterly flow over Southcentral as the upper trough axis
moves into the Gulf, a turn to a colder and potentially drier
pattern could take shape for the beginning of the weekend.

Out west, conditions look to remain unsettled for interior
locations of Southwest Alaska Wednesday as the area contends with
weak shortwaves pivoting back to the west from the upper low in
the Gulf. Meanwhile, another shortwave looks to dig southward from
the from the northern Bering Sea and cause a weak low pressure to
spin up near the Southwest coast/eastern Bering Thursday bringing
another chance at precipitation for coastal locations in the
morning and working into interior Southwest during the evening and
overnight Thursday. Conditions then quiet down for Friday and
Saturday.

The western and central Bering Sea/Aleutian Chain remain relatively
benign in the weather department for most of the long-term period
while the eastern Bering/Aleutian Chain contends with continued
gusty northerly flow through Thursday. However, there is some
uncertainty and questions whether a storm will form in the North
Pacific Wednesday evening; and if it forms, how far north does it
make it. The GFS is the most aggressive with the warm front
skirting the central and eastern Aleutian Chain Thursday and
Friday. Meanwhile, other guidance does not show a storm forming at
all. Guidance is beginning to key in on a Kamchatka low sending
its front eastward towards the western Bering/Aleutian Chain
Friday into Saturday. This will provide increased chances at
precipitation and gusty conditions. Winds look to be only gales at
this time.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning: 191 195
		 Winter Weather Advisory: 155 161
MARINE...Hurricane Force Wind Warning: Central Bering, Western Aleutians
		 Storm Warning: Western/Eastern Bering, Central Aleutians,
		 Pribilof Islands
	 	 Gale Warning: Alaska Peninsula - Bering Side, Eastern Aleutians,
		 Kuskokwim Delta Coast, Saint Matthew Island
		 Heavy Freezing Spray Warning: Kuskokwim Delta Coast
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KM
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CQ
LONG TERM...DAN

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
1236 PM AKDT Sun Mar 19 2023

AKZ101-111-192145-
Anchorage-Matanuska Valley-
Including the cities of Anchorage, Eagle River, Indian, Eklutna,
Palmer, Wasilla, Sutton, and Chickaloon
1236 PM AKDT Sun Mar 19 2023

...BLACK ICE ON AREA ROADWAYS THIS MORNING...

Rain and warm weather overnight followed by a quick freeze this
morning has resulted in black ice forming on area roadways. This
should melt as the sun rises and warms the road surfaces. Use
caution if traveling early this morning, as roads and sidewalks
are slick.