Gale Warning 835, NWS Anchorage, AK

786 
FZAK51 PAFC 311237
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
337 AM AKST Thu Dec 31 2020

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-010115-
337 AM AKST Thu Dec 31 2020
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A 974 mb low moves into the southern Gulf this evening. Its front
extends across the western and central Gulf through Fri.

$$

PKZ119-010115-
Cape Suckling to Cape Cleare-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...E wind 15 kt. N winds gusting to 30 kt out of the Copper
River Delta. Seas 7 ft.
.TONIGHT...NE wind 20 kt. Gusts to 40 kt out of the Copper River 
Delta. Seas 7 ft building to 12 ft after midnight.
.FRI...NE wind 25 kt. Gusts to 40 kt out of the Copper River Delta. Seas
12 ft.
.FRI NIGHT...NE wind 25 kt. Seas 12 ft.
.SAT...N wind 20 kt. Seas 10 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 8 ft.

$$

PKZ120-010115-
Cape Cleare to Gore Point-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...E wind 15 kt. Seas 7 ft.
.TONIGHT...NE wind 20 kt. Seas 11 ft.
.FRI...NE wind 20 kt. Seas 12 ft.
.FRI NIGHT...NE wind 25 kt. Seas 11 ft.
.SAT...NW wind 20 kt. Seas 9 ft.
.SUN...SW wind 20 kt. Seas 8 ft.
.MON...S wind 15 kt. Seas 7 ft.

$$

PKZ121-010115-
Resurrection Bay-
337 AM AKST Thu Dec 31 2020

.TODAY...N wind 10 kt. Seas 2 ft.
.TONIGHT...N wind 10 kt increasing to 15 kt with gusts to 25 kt after
midnight. Seas 3 ft. Freezing spray.
.FRI...N wind 20 kt. Seas 4 ft. Freezing spray.
.FRI NIGHT...N wind 20 kt. Seas 4 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SUN...N wind 15 kt. Seas 3 ft.
.MON...N wind 10 kt. Seas 2 ft.

$$

PKZ125-010115-
Prince William Sound-
337 AM AKST Thu Dec 31 2020

.TODAY...NE wind 10 kt. Seas 2 ft.
.TONIGHT...N wind 10 kt increasing to 15 kt after midnight. Seas
2 ft.
.FRI...N wind 15 kt. Seas 2 ft.
.FRI NIGHT...N wind 15 kt. Seas 2 ft.
.SAT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 10 kt. Seas 2 ft.

$$

PKZ126-010115-
Port Valdez-
337 AM AKST Thu Dec 31 2020

.TODAY...NE wind 10 kt. Seas 2 ft. Patchy freezing fog.
.TONIGHT...E wind 15 kt. Gusts to 25 kt.  Seas 3 ft. Freezing spray.
.FRI...E wind 15 kt. Gusts to 25 kt. Seas 3 ft. Freezing spray.
.FRI NIGHT...E wind 15 kt. Seas 3 ft.
.SAT...E wind 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON...E wind 10 kt. Seas 2 ft.

$$

PKZ127-010115-
Valdez Narrows-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...N wind 25 kt. Seas 3 ft. Freezing spray.
.TONIGHT...N wind 30 kt. Seas 3 ft. Freezing spray.
.FRI...N wind 30 kt. Seas 3 ft. Freezing spray.
.FRI NIGHT...N wind 30 kt. Seas 3 ft.
.SAT...N wind 25 kt. Seas 3 ft.
.SUN...NE wind 20 kt. Seas 3 ft.
.MON...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-010115-
Valdez Arm-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...NE wind 20 kt. Seas 4 ft.
.TONIGHT...NE wind 25 kt. Seas 5 ft. Freezing spray.
.FRI...NE wind 25 kt. Seas 5 ft. Freezing spray.
.FRI NIGHT...NE wind 25 kt. Seas 5 ft.
.SAT...NE wind 20 kt. Seas 4 ft.
.SUN THROUGH MON...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-010115-
Passage Canal-
337 AM AKST Thu Dec 31 2020

.TODAY...Variable wind less than 10 kt. Seas 2 ft.
.TONIGHT...Variable wind less than 10 kt becoming W 10 kt after
midnight. Seas 2 ft.
.FRI...W wind 10 kt. Seas 2 ft.
.FRI NIGHT...W wind 15 kt. Seas 2 ft.
.SAT...W wind 15 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON...E wind 10 kt. Seas 2 ft.

$$

PKZ130-010115-
West of Barren Islands including Kamishak Bay-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NE wind 30 kt. Seas 9 ft. 
.TONIGHT...NE wind 30 kt. Seas 11 ft. 
.FRI...NE wind 30 kt. Seas 10 ft.
.FRI NIGHT...N wind 25 kt. Seas 9 ft.
.SAT...NW wind 20 kt. Seas 5 ft.
.SUN...NW wind 15 kt. Seas 3 ft.
.MON...N wind 15 kt. Seas 4 ft.

$$

PKZ131-010115-
Barren Islands East-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...E wind 20 kt. Seas 7 ft.
.TONIGHT...E wind 25 kt. Seas 13 ft.
.FRI...NE wind 20 kt. Seas 12 ft.
.FRI NIGHT...NE wind 25 kt. Seas 11 ft.
.SAT THROUGH SUN...W wind 20 kt. Seas 9 ft.
.MON...S wind 15 kt. Seas 8 ft.

$$

PKZ132-010115-
Marmot Island to Sitkinak-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...E wind 30 kt. Seas 8 ft building to 14 ft in the
afternoon.
.TONIGHT...E wind 30 kt. Seas 17 ft.
.FRI...NE wind 20 kt. Seas 13 ft.
.FRI NIGHT...N wind 25 kt. Seas 11 ft.
.SAT...NW wind 25 kt. Seas 12 ft.
.SUN...W wind 20 kt. Seas 11 ft.
.MON...S wind 15 kt. Seas 10 ft.

$$

PKZ136-010115-
Chiniak Bay-
337 AM AKST Thu Dec 31 2020

.TODAY...NE wind 10 kt becoming E 15 kt in the afternoon. Seas 4
ft.
.TONIGHT...E wind 20 kt. Seas 5 ft.
.FRI...NE wind 20 kt. Seas 5 ft.
.FRI NIGHT...N wind 20 kt. Seas 4 ft.
.SAT...NW wind 20 kt. Seas 2 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON...Variable wind less than 10 kt. Seas 3 ft.

$$

PKZ137-010115-
Marmot Bay-
337 AM AKST Thu Dec 31 2020

.TODAY...E wind 10 kt increasing to 15 kt in the afternoon. Seas
4 ft.
.TONIGHT...E wind 20 kt. Seas 7 ft.
.FRI...E wind 15 kt becoming NE 10 kt in the afternoon. Seas 4 ft.
.FRI NIGHT...N wind 15 kt. Seas 3 ft.
.SAT...NW wind 15 kt. Seas 2 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON...Variable wind less than 10 kt. Seas 3 ft.

$$

PKZ138-010115-
Shelikof Strait-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NE wind 25 kt. Seas 8 ft.
.TONIGHT...NE wind 30 kt. Seas 10 ft.
.FRI...NE wind 25 kt. Seas 8 ft.
.FRI NIGHT...NE wind 25 kt. Seas 8 ft.
.SAT...NW wind 20 kt. Seas 4 ft.
.SUN...Variable wind 10 kt. Seas 3 ft.
.MON...NE wind 15 kt. Seas 3 ft.

$$

PKZ139-010115-
Cook Inlet Kalgin Island to Point Bede-
337 AM AKST Thu Dec 31 2020

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NE wind 25 kt. Seas 7 ft. Freezing spray.
.TONIGHT...NE wind 25 kt. Seas 9 ft. Freezing spray.
.FRI...N wind 25 kt. Seas 8 ft. Freezing spray.
.FRI NIGHT...N wind 25 kt. Seas 8 ft.
.SAT...N wind 20 kt. Seas 5 ft.
.SUN...N wind 15 kt. Seas 3 ft.
.MON...N wind 20 kt. Seas 5 ft.

$$

PKZ140-010115-
Cook Inlet North of Kalgin Island-
337 AM AKST Thu Dec 31 2020

.TODAY...NE wind 20 kt. Seas 5 ft. Freezing spray.
.TONIGHT...NE wind 15 kt. Seas 4 ft. Freezing spray.
.FRI...NE wind 10 kt. Seas 3 ft.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.
.SUN...N wind 10 kt. Seas 3 ft.
.MON...N wind 15 kt. Seas 3 ft.

$$

PKZ141-010115-
Kachemak Bay-
337 AM AKST Thu Dec 31 2020

.TODAY...NE wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.TONIGHT...NE wind 10 kt. Seas 2 ft.
.FRI...Variable wind less than 10 kt becoming NE 10 kt in the
afternoon. Seas 2 ft.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft.
.SAT THROUGH MON...N wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
543 PM AKST Tue Dec 29 2020

.ANALYSIS AND UPPER LEVELS...

Deep southerly flow between a nearly stationary trough centered
over the Western Bering and a ridge of high pressure over the
Interior/Yukon Territory continues to bring widespread cloudcover
and scattered rain/snow showers to the Southwest mainland. Just to
the east of this cloud cover, subsidence with the high pressure
allowed for a clear and cold morning today, along with some patchy
fog around Upper Cook Inlet.

A shortwave trough within the southerly flow over Kodiak Island
brought rain to the area today. This feature will continue
progressing northward this evening, and will be the focus for
light snow for much of Southcentral overnight. A weak low under
this shortwave trough is beginning the cross over the AKPen where
it is bringing rain and wet snow to the area as it progresses
northward. The western Bering low continues to slowly weaken and
drift westward. Winds from this system have now fallen below gale
force, but otherwise is not producing significant impacts outside
continued scattered shower activity.

&&

.MODEL DISCUSSION...

In general, synoptic model agreement remains good through
Wednesday leading to above average forecast confidence for much of
the area. There are some very minor timing differences with how
quickly the shortwave over Kodiak Island will move northward into
Southcentral early Wednesday morning that is producing some
uncertainty in the onset/dissipation of any snowfall, but
confidence is good in the forecast trends over the next 2 days.
Model agreement also remains very good with the extremely deep
low that will move into the Bering by Thursday. There still
remains around 10 mb in spread in this systems extremely low
central pressure between the most aggressive EC and least
aggressive NAM. The forecast continues to favor the GFS as a
middle ground solution. As far as impacts from this system
however, there is very good agreement in the location and timing for
highest winds and seas into Friday.

&&

.AVIATION...

PANC...VFR conditions with light/variable winds will continue
until overnight tonight, when a few hours of IFR snow and around
1 inch of accumulation is expected. As is mentioned in the model
discussion above there is some uncertainty in exact timing of
this feature, but there is generally good confidence that VFR
conditions will redevelop again after 18z on Wednesday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...

In the next two days, a mix of rain and snow will move across
much of Southcentral and Kodiak Island. A frontal boundary over
the northern Gulf will drive heavier rainfall inland this evening
before transitioning to snow along Prince William Sound and
Anchorage Bowl northward tonight. Meanwhile, warm temperatures
over southern Kenai Peninsula and Kodiak Island will maintain
precipitation in the form of liquid throughout most of the
forecast period.

A stacked low over Shelikof Strait will bring another round of
snowfall across the Bowl and Southcentral by Wednesday and
Wednesday night. GFS and NAM struggles a bit on the placement of
the upper low, with the GFS aiming to keep the upper low over
Anchorage Bowl and delay its motion eastward in the next couple
days. NAM whips the upper low past Anchorage Bowl by Thursday
morning and parks it over Prince William Sound through Thursday
night. Should the upper level low linger over the Anchorage Bowl
or PWS, new updates to the forecast will be provided. For now, the
amount of snowfall would likely be more over the Anchorage Bowl
than other areas tonight.

Much colder temperatures aloft will linger between the Susitna
Valley and Copper River Basin before spreading eastward toward
Valdez and Thompson Pass on Thursday. At 850 mb, environmental
temperatures upstream will continue to fall to -16 degrees
Celsius by Thursday night. The potential for patchy freezing fog
around Port Valdez and Thompson Pass is feasible starting
Wednesday night through Thursday night. Light winds near Valdez
northward and along the southern Cook Inlet and lower temperatures
in the next couple nights will invite freezing fog in those
areas. As a result, it'll be relatively quiet and a bit cooler in
the next couple days.

&&

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

An upper level short-wave trough and surface low along the Alaska
Peninsula will lift northward across the Bristol Bay region
tonight through Thursday, bringing periods of light precipitation.
The airmass is warm enough to produce mostly rain this afternoon
and evening, but expect a transition to mostly snow overnight.
Snow accumulation will be light, with an inch or two at most by
Thursday afternoon. The remainder of Southwest Alaska will be on
the fringes of this system, with patchy light precipitation.

A ridge of high pressure will build overhead Wednesday night
through Thursday, leading to dry conditions, cooler temperatures,
and most likely areas of fog. For Thursday night through Friday,
a strong front associated with a hurricane-force low along the
western Aleutians will near the Southwest Alaska coast. It looks
like ridging over the mainland will hold the front at bay, so most
areas will likely remain dry. However, expect an increase in
easterly winds, especially along the immediate coastline.

&&

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

A large low spinning over the western Bering Sea will continue to
produce showers and gusty winds across much of the region through
Wednesday. Attention will then shift to what could end up being a
record-breaking storm. A weak low near Japan will rapidly
intensify ahead of short-wave trough moving out of Asia, aided by
a 200 kt+ upper level jet and extreme thermal gradients
between a sub-tropical air mass over the Pacific (850 mb
temperatures of +12 degrees Celsius or warmer) and a polar
airmass over Asia (-20 degrees Celsius near the coast). This low
will bottom out as it reaches the western Aleutian Islands
Thursday morning. Models continue to trend deeper with the central
pressure, with the various solutions ranging from 919 mb to 930
mb. This will rival the Bering Sea storm from November 2014 which
developed from the remnants of Typhoon Nuri. The estimated
central pressure of that storm was 924 mb. In any case, the
combination of extremely low pressure and rapidly falling pressure
as the storm arrives will lead to widespread storm force to
hurricane force winds along the Aleutians and into the Bering Sea
Wednesday night through Thursday. The low will stall along or
north of the western Aleutians, which means the most extreme
weather will remain in that area. The frontal system will progress
eastward across the Bering Sea and Aleutians Thursday through
Friday, weakening as it progresses eastward. Winds will remain
elevated along the Aleutians the entire time, as arctic air feeds
into the back side of the storm.

Have issued a High Wind Warning from Adak to Atka for the leading
front with southeasterly winds. At the moment it appears the
strongest core of winds on the south side of the low center
Thursday will remain away from populated islands. This could
change if the low track shifts, so stay tuned to the latest
forecasts.

&&

.MARINE (Days 3 through 5: Friday through Sunday)...

Gulf of Alaska:
Confidence remains high for a broad low center to gradually drift
northwards over the southern Gulf on Friday with gale force winds
likely north of the low, or near the northern Gulf Coast. Winds
should decrease to small craft levels as the low and associated
front weaken from late Friday to early Saturday. Forecast
confidence decreases from Saturday to Sunday as the aforementioned
low slowly drifts towards the Gulf Coast and continues to weaken.

Several smaller lows may rotate around the broader circulation
this weekend and potentially track across the southern Gulf with
locally small craft to gale force winds possible as they push
eastwards. However, confidence for these individual low tracks is
poor at this time. This uncertainly stems from the placement of
the Gulf low by the weekend and from differences in the evolution
of the extremely deep low spanning across the Bering during the
forecast period.

Aleutians/Bering:
Forecast remains on track for an extremely deep to potentially
record setting low to track across the Western Aleutians and into
the western Bering Thursday into Friday. By Thursday evening, the
center will be positioned north of Attu with widespread storm
force winds wrapping the low to the west of Adak and across much
of the Bering, with an area of hurricane force winds likely
between Attu and Adak across the Rat Islands. Southeast gale to
storm force winds are also expected ahead of the low's front as it
tracks through the Central Bering/Aleutians and Pribilofs on
Friday. Waves as high as 40-55 ft will be possible on Friday near
the Pacific coastline of the far Western Aleutians until winds
weaken below storm force early Saturday. By Saturday, there is
good confidence the low will stall in the far western bering as it
slowly fills with winds weakening to gale force on Saturday, then
dropping to mostly small crafts from late Saturday to Sunday.
Winds along the front will quickly diminish as the boundary also
stalls in the eastern Bering on Saturday morning.

&&

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

Despite continuing to have the remnants of a potentially record
setting low in the Bering, the weather for much of the southern
mainland for Saturday look quite benign with high pressure
dominating most areas. There is good agreement in low pressure in
the extreme southern Gulf through Saturday, that will produce
outflow winds to the typical channeled areas of the Gulf Coast,
however this does not look to impact most interior locations.
Starting Sunday, this Gulf low pressure will begin to lift into
the north Gulf Coast, likely bringing with it warming conditions
and a chance of precipitation to the Gulf Coast/Southcentral. By
Monday, model agreement becomes very poor, so forecast confidence
for early next week is very low.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning: 185.
MARINE...Hurricane Force Wind Warning: 177 178.
Storm Warning: 175 176 411 413.
Gale Warning: 119 130 185 412.

&&

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...CB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SEB
MARINE/LONG TERM...AS/DEK