Gale Warning 787, NWS Anchorage, AK

570 
FZAK51 PAFC 170021
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
321 PM AKST Wed Dec 16 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.

PKZ197-171300-
321 PM AKST Wed Dec 16 2020
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A 974 mb low 170 nm south of Sitkinak Thu morning moves to 150 nm
west of Kodiak City at 972 mb by Thu afternoon and then moves 
inland over the North Gulf Coast by Fri afternoon.

$$

PKZ119-171300-
Cape Suckling to Cape Cleare-
321 PM AKST Wed Dec 16 2020

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

.TONIGHT...W wind 15 kt becoming SE 20 kt after midnight. Seas 8 ft.
.THU...E wind 30 kt increasing to 40 kt in the afternoon. Seas
12 ft. Rain with snow.
.THU NIGHT...NE wind 35 kt diminishing to 25 kt after midnight.
Seas 13 ft. Rain and snow.
.FRI...N wind 25 kt. Seas 11 ft.
.FRI NIGHT...S wind 20 kt. Seas 15 ft.
.SAT THROUGH SUN...W wind 35 kt. Seas 16 ft.
.MON...S wind 35 kt. Seas 17 ft.

$$

PKZ120-171300-
Cape Cleare to Gore Point-
321 PM AKST Wed Dec 16 2020

...GALE WARNING THURSDAY...

.TONIGHT...W wind 15 kt becoming E 20 kt after midnight. Seas 6
ft. Rain.
.THU...NE wind 35 kt. Seas 11 ft. Rain with snow.
.THU NIGHT...NE wind 30 kt becoming NW 15 kt after midnight. Seas
13 ft.
.FRI...NW wind 15 kt. Seas 9 ft.
.FRI NIGHT...NW wind 25 kt. Seas 10 ft.
.SAT THROUGH SUN...W wind 40 kt. Seas 15 ft.
.MON...S wind 40 kt. Seas 21 ft.

$$

PKZ121-171300-
Resurrection Bay-
321 PM AKST Wed Dec 16 2020

.TONIGHT...N wind 10 kt increasing to 20 kt after midnight. Seas 4 
ft. Freezing spray.
.THU...N wind 20 kt. Seas 4 ft. Freezing spray. Snow.
.THU NIGHT...N wind 20 kt. Seas 4 ft. Freezing spray.
.FRI...N wind 20 kt. Seas 4 ft.
.FRI NIGHT...N wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...N wind 15 kt. Seas 3 ft.
.MON...E wind 20 kt. Seas 4 ft.

$$

PKZ125-171300-
Prince William Sound-
321 PM AKST Wed Dec 16 2020

.TONIGHT...NE wind 10 kt increasing to 15 kt after midnight. Seas
2 ft.
.THU...NE wind 20 kt. Seas 4 ft.
.THU NIGHT...N wind 20 kt. Seas 3 ft.
.FRI...N wind 10 kt. Seas 2 ft.
.FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...N wind 10 kt. Seas 2 ft.
.MON...E wind 25 kt. Seas 6 ft.

$$

PKZ126-171300-
Port Valdez-
321 PM AKST Wed Dec 16 2020

.TONIGHT...NE wind 10 kt. Seas 2 ft.
.THU...E wind 15 kt. Seas 3 ft. Freezing spray.
.THU NIGHT...E wind 15 kt. Seas 3 ft. Freezing spray.
.FRI...E wind 15 kt. Seas 3 ft.
.FRI NIGHT...E wind 10 kt. Seas 2 ft.
.SAT...E wind 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON...NE wind 10 kt. Seas 2 ft.

$$

PKZ127-171300-
Valdez Narrows-
321 PM AKST Wed Dec 16 2020

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...NE wind 25 kt. Seas 3 ft. Freezing spray.
.THU...NE wind 30 kt. Seas 4 ft. Freezing spray.
.THU NIGHT...NE wind 35 kt. Seas 4 ft. Freezing spray.
.FRI AND FRI NIGHT...NE wind 25 kt. Seas 3 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON...NE wind 10 kt. Seas 2 ft.

$$

PKZ128-171300-
Valdez Arm-
321 PM AKST Wed Dec 16 2020

...SMALL CRAFT ADVISORY THURSDAY AND THURSDAY NIGHT...

.TONIGHT...NE wind 15 kt. Seas 3 ft. Freezing spray.
.THU...NE wind 15 kt increasing to 25 kt in the afternoon. Seas 3
ft building to 5 ft in the afternoon. Freezing spray.
.THU NIGHT...NE wind 25 kt. Seas 5 ft.
.FRI AND FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...NE wind 10 kt. Seas 2 ft.
.MON...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-171300-
Passage Canal-
321 PM AKST Wed Dec 16 2020

.TONIGHT...W wind 15 kt becoming variable wind 10 kt after midnight.
Seas 2 ft. Freezing spray. Snow.
.THU...E wind 10 kt. Seas 2 ft. Snow.
.THU NIGHT...W wind 10 kt increasing to 15 kt after midnight. Seas
2 ft. Freezing spray.
.FRI...Variable wind less than 10 kt. Seas 2 ft.
.FRI NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SAT THROUGH SUN...Variable wind 10 kt. Seas 2 ft.
.MON...E wind 15 kt. Seas 2 ft.

$$

PKZ130-171300-
West of Barren Islands including Kamishak Bay-
321 PM AKST Wed Dec 16 2020

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...Variable wind 15 kt becoming NE 35 kt after midnight. 
Seas 8 ft building to 14 ft after midnight.
.THU...NE wind 35 kt. Seas 16 ft.
.THU NIGHT...NE wind 30 kt. Seas 12 ft subsiding to 7 ft after
midnight.
.FRI AND FRI NIGHT...NW wind 20 kt. Seas 4 ft.
.SAT THROUGH SUN...W wind 30 kt. Seas 8 ft.
.MON...SE wind 35 kt. Seas 10 ft.

$$

PKZ131-171300-
Barren Islands East-
321 PM AKST Wed Dec 16 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...Variable wind 15 kt becoming E 25 kt after midnight. Seas
5 ft building to 10 ft after midnight. Rain.
.THU...NE wind 30 kt. Seas 10 ft. Rain with snow.
.THU NIGHT...N wind 30 kt becoming NW 20 kt after midnight. Seas
12 ft.
.FRI...NW wind 15 kt. Seas 9 ft.
.FRI NIGHT...W wind 25 kt. Seas 11 ft.
.SAT THROUGH SUN...W wind 35 kt. Seas 13 ft.
.MON...S wind 35 kt. Seas 22 ft.

$$

PKZ132-171300-
Marmot Island to Sitkinak-
321 PM AKST Wed Dec 16 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SE wind 15 kt becoming E 25 kt after midnight. Seas 5 ft 
building to 10 ft after midnight. Rain.
.THU...NE wind 30 kt except NE 25 kt N of Dangerous Cape. Seas
10 ft. Rain.
.THU NIGHT...NW wind 25 kt. Seas 12 ft.
.FRI AND FRI NIGHT...W wind 25 kt. Seas 12 ft.
.SAT THROUGH SUN...W wind 30 kt. Seas 11 ft.
.MON...S wind 40 kt. Seas 24 ft.

$$

PKZ136-171300-
Chiniak Bay-
321 PM AKST Wed Dec 16 2020

.TONIGHT...SE wind 10 kt becoming E 15 kt after midnight. Seas 2 ft
building to 6 ft after midnight. Rain with snow.
.THU...NE wind 20 kt. Seas 6 ft subsiding to 3 ft in the
afternoon. Rain with snow.
.THU NIGHT...NW wind 15 kt diminishing to 10 kt after midnight.
Seas 2 ft.
.FRI...NW wind 10 kt. Seas 2 ft.
.FRI NIGHT...W wind 20 kt. Seas 3 ft.
.SAT THROUGH SUN...W wind 25 kt. Seas 4 ft.
.MON...S wind 30 kt. Seas 11 ft.

$$

PKZ137-171300-
Marmot Bay-
321 PM AKST Wed Dec 16 2020

.TONIGHT...E wind 10 kt increasing to 15 kt after midnight. Seas
2 ft building to 6 ft after midnight. Rain and snow.
.THU...NE wind 20 kt. Seas 6 ft. Rain with snow.
.THU NIGHT...NW wind 15 kt diminishing to 10 kt after midnight.
Seas 2 ft.
.FRI...NW wind 10 kt. Seas 2 ft.
.FRI NIGHT...W wind 15 kt. Seas 3 ft.
.SAT...W wind 30 kt. Seas 6 ft.
.SUN...SW wind 25 kt. Seas 6 ft.
.MON...SE wind 30 kt. Seas 12 ft.

$$

PKZ138-171300-
Shelikof Strait-
321 PM AKST Wed Dec 16 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...Variable wind less than 15 kt becoming NE 30 kt after 
midnight. Seas 7 ft building to 13 ft after midnight. Snow and rain.
.THU...NE wind 30 kt. Seas 13 ft. Snow and rain.
.THU NIGHT...NE wind 25 kt. Seas 8 ft subsiding to 3 ft after
midnight.
.FRI AND FRI NIGHT...W wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...SW wind 25 kt. Seas 6 ft.
.MON...SE wind 30 kt. Seas 8 ft.

$$

PKZ139-171300-
Cook Inlet Kalgin Island to Point Bede-
321 PM AKST Wed Dec 16 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...Variable wind less than 15 kt becoming NE 30 kt after
midnight. Seas 5 ft building to 11 ft after midnight. Freezing spray
and patchy freezing fog.
.THU...N wind 30 kt. Seas 12 ft. Freezing spray.
.THU NIGHT...NE wind 30 kt. Seas 10 ft subsiding to 5 ft after
midnight. Freezing spray.
.FRI...NE wind 20 kt. Seas 4 ft.
.FRI NIGHT...N wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 4 ft.
.MON...NE wind 25 kt. Seas 5 ft.

$$

PKZ140-171300-
Cook Inlet North of Kalgin Island-
321 PM AKST Wed Dec 16 2020

.TONIGHT...N wind 15 kt. Seas 4 ft. Freezing spray and patchy
fog.
.THU...NE wind 20 kt. Seas 6 ft. Freezing spray.
.THU NIGHT...NE wind 15 kt. Seas 4 ft. Freezing spray.
.FRI...Variable wind less than 10 kt. Seas 2 ft.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft.
.SAT THROUGH SUN...N wind 10 kt. Seas 3 ft.
.MON...NE wind 20 kt. Seas 4 ft.

$$

PKZ141-171300-
Kachemak Bay-
321 PM AKST Wed Dec 16 2020

.TONIGHT...NE wind 10 kt. Seas 2 ft. Patchy freezing fog.
.THU...N wind 15 kt. Seas 2 ft. Freezing spray.
.THU NIGHT...N wind 15 kt diminishing to 10 kt after midnight.
Seas 2 ft.
.FRI AND FRI NIGHT...N wind 10 kt. Seas 2 ft.
.SAT...W wind 20 kt. Seas 4 ft.
.SUN...W wind 15 kt. Seas 4 ft.
.MON...E wind 15 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
429 PM AKST Tue Dec 15 2020

.ANALYSIS AND UPPER LEVELS...

An upper level trough is in place along the western Alaska coast
while an upper level ridge extends across the eastern part of the
state along the Alcan border. Moisture associated with a low in
the southeastern Gulf continues to be advected inland over
Southcentral. Light snow showers are falling across much of the
area from the Kenai Peninsula north to the Mat-Su Valleys. Light
snow also extends eastward over the Copper River Basin. Meanwhile
farther west, a low centered over Adak is slowly tracking
eastward, spreading rain and cloud cover across the Aleutian
Chain. As the trough centered over the western half of the state
slowly lifts eastward, snow showers will continue over the
Kuskowim Delta and Bristol Bay region this afternoon.

&&

.MODEL DISCUSSION...

Model solutions are in good agreement through the short term. By
Wednesday afternoon, there is disagreement regarding the position
of a low tracking across the Alaska Peninsula and over Kodiak
Island into the Gulf. Farther west, models continue to struggle to
resolve a complex low over the Bering through the end of the week.

&&

.AVIATION...

PANC...Light snow will continue overnight. A period of heavier
snow is expected around 9-12z which should cause the worst
conditions within the TAF window.

&&

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

Moisture on the backside of a low in the eastern Gulf, continues
to propagate across Southcentral this afternoon. This will
allow for a continuation of the snowfall we've seen today through
the overnight hours and into tomorrow morning/early afternoon.

Tomorrow morning into the early afternoon, a strong, upper level
shortwave looks to provide more lift. This, combined with upslope
flow, will provide for an increase in snowfall intensity for the
western Chugach early tomorrow morning for a 3 to 6 hour period.
Snowfall intensity, due to the shortwave, will also increase along
the coastal areas of Prince William Sound, as it moves from west
to east through the day on Wednesday.

Another system is on track to approach the southwestern Gulf
Wednesday night. As the low moves towards Kodiak Island, a wintry
mix of precipitation is anticipated. Additionally, gale force
northeasterly winds are expected down Cook Inlet and into Shelikof
Strait. Offshore flow will continue to strengthen with the
increasing pressure gradient as this system approaches the
northern Gulf Coast. Expect gusty winds through the Matanuska
Valley, Copper River Delta, Thompson Pass and Valdez waters.

Temperatures will remain on a downward trend through the forecast
period for the Copper River Basin as cold air aloft settles into
the Basin.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tonight
through Friday)...
Areas of very light snow will persist tonight, primarily over
interior Southwest Alaska, as an upper trough swings through.
A weaker trough will follow behind on Wednesday, maintaining low
clouds, patchy fog, and a few flurries across the region. There
has been a change in the forecast for a storm tracking south of
the Alaska Wednesday and into the Gulf of Alaska Thursday. This
storm will take a further north track, with support from a
negatively tilted trough aloft. As a result, expect snow to
overspread much of Bristol Bay Thursday afternoon through
evening. Could also see snow make it up to the Kuskokwim delta,
though confidence in that is lower. Nonetheless, accumulation
will be light. Some locally gusty northerly winds from roughly
Dillingham westward will also produce some blowing snow, which
will reduce visibilities at times. This will all quickly wind
down Thursday night into friday as both the low and upper trough
exit. Friday then looks quiet as a ridge briefly moves overhead.
Never really see any significant low level winds or temperature
advection, so low clouds and patchy fog will likely remain in
place.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3/Tonight
through Friday)...
Progressive cyclonic flow aloft, with a plethora of embedded
short-waves will lead to development of multiple compact lows over
the next few days. Forecast confidence in the track of most of
these storms is quite low. Fortunately, they will generally move
through any one area pretty fast and the stronger winds will be
confined to a small area near the low center. At the moment, it
appears the strongest of these lows will be one that tracks from
the North Pacific to near Adak Wednesday night, then eastward to
south of the Pribilof Islands Thursday night. Expect high end
gales on the south side of this low. The overall pattern will
produce rain and snow showers, with steadier precipitation near
low centers.

&&

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

Gulf of Alaska: There is a very good agreement that a gale force
low will impact the Gulf on Friday. Most of the gale force wind
activity is expected to be on the southern side of the low center.
Model guidance spreads out after this with the possibility for
relatively benign conditions across the Gulf whereas the other
models are showing at least small craft westerlies across the Gulf
Saturday through Sunday which is currently what we are leaning
towards. There is potential for these to be gale force as well
but there is still uncertainty for this.

Bering Sea: For Friday and Saturday, generally benign conditions
are expected across the Bering with winds below 30 kts and seas
less than 15 feet with some rather small compact lows. The big
weather maker is a rather large gale force storm system that is
expected to impact the Bering Saturday evening through the day
Sunday which all model guidance agrees on. As a result of the
winds, waves (greater than 15 feet) will be on the increase as
well.

&&

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

The weather pattern during the first half of the forecast time
period continues to show strong Arctic high pressure locked in
over the Interior of Alaska east to the Yukon Territory. The
subtropical jet continues to remain fairly active during this time
frame as well with multiple storms trying to move northeastward
and into the cold air that is locked in across the interior areas
of Alaska and the Yukon. Latest data suggests that coastal areas
of the eastern Kenai Peninsula, Kodiak Island, and Prince William
Sound area have the best chance to see any meaningful
precipitation during this timeframe. Some of the energy from these
systems may occasionally send some light snow into the Anchorage
area and across Southwest but this time frame looks to remain on
the colder side with temperatures averaging below normal. The
exact track and intensity of any of these systems in this time
frame continues to remain highly uncertain and will become more
clearer over the coming days.

Farther west, model guidance has since come into much better
agreement across the Bering and for Southwest Alaska for a rather
large low to impact the area. The details of this system remain
uncertain as this time but the threat is there for it bring a
decent amount of warmer air northward towards Southwest Alaska
Monday and Tuesday potentially creating precipitation type issues
for this time period. Stay tuned as we continue to hone in on the
details of this system in the coming days.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gales 130 138 172 175-177.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KO
SOUTHCENTRAL ALASKA...CK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SEB
MARINE/LONG TERM...MV