Small Craft Advisory 831, NWS Anchorage, AK

051 
FZAK51 PAFC 192358
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
358 PM AKDT Tue Oct 19 2021

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.

PKZ197-201315-
358 PM AKDT Tue Oct 19 2021
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A 977 mb low 125 nm northeast of Kodiak City this afternoon will 
move inland tonight. A second 982 mb low 300 nm southeast of
Cordova Tuesday night will move 40 nm southwest of Cordova at 987
mb Wednesday afternoon. The low then moves inland Wednesday 
evening. A front enters the western Gulf Thursday afternoon. 

$$

PKZ119-201315-
Cape Suckling to Cape Cleare-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 15 ft.
.WED...E wind 25 kt becoming NE 15 kt in the afternoon. Seas 14
ft.
.WED NIGHT...SW wind 20 kt. Seas 13 ft.
.THU...SE wind 20 kt. Seas 8 ft.
.THU NIGHT...E wind 20 kt. Seas 7 ft.
.FRI...E wind 30 kt. Seas 18 ft.
.SAT...E wind 25 kt. Seas 18 ft.
.SUN...E wind 20 kt. Seas 15 ft.

$$

PKZ120-201315-
Cape Cleare to Gore Point-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt diminishing to 15 kt after midnight. Seas
14 ft.
.WED...N wind 15 kt. Seas 11 ft.
.WED NIGHT...Variable wind 10 kt. Seas 11 ft.
.THU...Variable wind 10 kt. Seas 9 ft.
.THU NIGHT...E wind 20 kt. Seas 7 ft.
.FRI...NE wind 25 kt. Seas 16 ft.
.SAT...NE wind 20 kt. Seas 16 ft.
.SUN...NE wind 15 kt. Seas 15 ft.

$$

PKZ121-201315-
Resurrection Bay-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...N wind 15 kt becoming S wind 25 kt in the evening. 
Diminishing to 15 kt after midnight. Seas 5 ft subsiding to 3 ft 
after midnight. Rain.
.WED...N wind 10 kt. Seas 2 ft. Rain.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain
showers.
.THU...Variable wind less than 10 kt. Seas 2 ft.
.THU NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.FRI THROUGH SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ125-201315-
Prince William Sound-
358 PM AKDT Tue Oct 19 2021

...GALE WARNING TONIGHT...

.TONIGHT...SE wind 35 kt diminishing to 25 kt after midnight. Seas
7 ft. Rain.
.WED...NE wind 15 kt becoming N 10 kt in the afternoon. Seas 3 ft.
Rain.
.WED NIGHT...NW wind 15 kt becoming SE 20 kt after midnight. Seas
3 ft. Rain showers.
.THU...SE wind 20 kt. Seas 3 ft.
.THU NIGHT...NE wind 15 kt. Seas 2 ft.
.FRI...NE wind 20 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 3 ft.
.SUN...NE wind 10 kt. Seas 2 ft.

$$

PKZ126-201315-
Port Valdez-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...E wind 15 kt diminishing to 10 kt after midnight. Seas
3 ft. Rain.
.WED...E wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft. Rain.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft. Widespread
rain showers.
.THU...Variable wind less than 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI THROUGH SUN...E wind 15 kt. Seas 3 ft.

$$

PKZ127-201315-
Valdez Narrows-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NE wind 25 kt. Seas 3 ft. Rain.
.WED...NE wind 20 kt. Seas 3 ft. Rain.
.WED NIGHT...N wind 15 kt. Seas 3 ft. Widespread rain showers.
.THU AND THU NIGHT...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SUN...N wind 20 kt. Seas 3 ft.

$$

PKZ128-201315-
Valdez Arm-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NE wind 25 kt. Seas 5 ft. Rain.
.WED...NE wind 15 kt diminishing to 10 kt in the afternoon. Seas
3 ft. Rain.
.WED NIGHT...Variable wind less than 10 kt becoming NE wind 15 kt
after midnight. Seas 3 ft. Widespread rain showers.
.THU...NE wind 15 kt. Seas 3 ft.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 4 ft.
.SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-201315-
Passage Canal-
358 PM AKDT Tue Oct 19 2021

...GALE WARNING TONIGHT...

.TONIGHT...E wind 35 kt diminishing to 20 kt after midnight. Seas
5 ft subsiding to 3 ft after midnight. Rain.
.WED...E wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft. Rain.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain
showers.
.THU...E wind 10 kt. Seas 2 ft.
.THU NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.FRI THROUGH SUN...E wind 10 kt. Seas 2 ft.

$$

PKZ130-201315-
West of Barren Islands including Kamishak Bay-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY WEDNESDAY NIGHT...

.TONIGHT...W wind 20 kt becoming SE 15 kt after midnight. Seas 4
ft. Rain showers.
.WED...Variable wind 10 kt becoming NW 20 kt in the afternoon.
Seas 5 ft.
.WED NIGHT...NW wind 25 kt. Seas 5 ft.
.THU...S wind 20 kt. Seas 5 ft.
.THU NIGHT...E wind 30 kt. Seas 8 ft.
.FRI...NE wind 30 kt. Seas 8 ft.
.SAT...N wind 20 kt. Seas 5 ft.
.SUN...NW wind 30 kt. Seas 7 ft.

$$

PKZ131-201315-
Barren Islands East-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 25 kt becoming SE 15 kt after midnight. Seas
13 ft.
.WED...Variable wind 10 kt becoming N 20 kt in the afternoon. Seas
10 ft.
.WED NIGHT...NW wind 25 kt. Seas 11 ft.
.THU...S wind 15 kt. Seas 9 ft.
.THU NIGHT...SE wind 25 kt. Seas 7 ft.
.FRI...NE wind 25 kt. Seas 14 ft.
.SAT...NE wind 20 kt. Seas 15 ft.
.SUN...N wind 25 kt. Seas 15 ft.

$$

PKZ132-201315-
Marmot Island to Sitkinak-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 11 ft.
.WED...NW wind 20 kt increasing to 30 kt in the afternoon. N of
Dangerous Cape, variable wind 10 kt becoming NW 15 kt in the
afternoon. Seas 10 ft.
.WED NIGHT...NW wind 25 kt. Seas 11 ft.
.THU...S wind 20 kt. Seas 10 ft.
.THU NIGHT...SE wind 30 kt. Seas 9 ft.
.FRI...SE wind 25 kt. Seas 19 ft.
.SAT...N wind 25 kt. Seas 19 ft.
.SUN...NW wind 30 kt. Seas 14 ft.

$$

PKZ136-201315-
Chiniak Bay-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...S wind 10 kt in the evening becoming variable less than
10 kt. Seas 4 ft. Rain showers.
.WED...Variable wind less than 10 kt becoming NW 10 kt in the
afternoon. Seas 4 ft.
.WED NIGHT...NW wind 10 kt. Seas 4 ft.
.THU...S wind 15 kt. Seas 4 ft.
.THU NIGHT...SE wind 25 kt. Seas 7 ft.
.FRI...E wind 20 kt. Seas 7 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SUN...NW wind 20 kt. Seas 3 ft.

$$

PKZ137-201315-
Marmot Bay-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...Variable wind less than 10 kt becoming W 10 kt after
midnight. Seas 3 ft.
.WED...Variable wind less than 10 kt becoming NW 10 kt in the
afternoon. Seas 2 ft. Rain showers.
.WED NIGHT...NW wind 15 kt becoming W 10 kt after midnight. Seas
2 ft.
.THU...S wind 15 kt. Seas 4 ft.
.THU NIGHT...SE wind 25 kt. Seas 7 ft.
.FRI...E wind 20 kt. Seas 7 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SUN...NW wind 20 kt. Seas 3 ft.

$$

PKZ138-201315-
Shelikof Strait-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...SW wind 15 kt. Seas 3 ft.
.WED...NW wind 20 kt. Seas 3 ft building to 5 ft in the afternoon.
.WED NIGHT...NW wind 20 kt. Seas 4 ft.
.THU...S wind 25 kt. Seas 4 ft.
.THU NIGHT...E wind 30 kt. Seas 7 ft.
.FRI...NE wind 25 kt. Seas 6 ft.
.SAT...N wind 20 kt. Seas 4 ft.
.SUN...NW wind 25 kt. Seas 5 ft.

$$

PKZ139-201315-
Cook Inlet Kalgin Island to Point Bede-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...NW wind 20 kt becoming S 10 kt after midnight. Seas 5
ft subsiding to 3 ft after midnight. Rain showers.
.WED...NE wind 10 kt becoming N 15 kt in the afternoon. Seas 3 ft.
.WED NIGHT...N wind 10 kt becoming W 15 kt after midnight. Seas
3 ft.
.THU...SE wind 15 kt. Seas 3 ft.
.THU NIGHT...NE wind 20 kt. Seas 5 ft.
.FRI...NE wind 30 kt. Seas 8 ft.
.SAT THROUGH SUN...N wind 15 kt. Seas 4 ft.

$$

PKZ140-201315-
Cook Inlet North of Kalgin Island-
358 PM AKDT Tue Oct 19 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NE wind 30 kt becoming SW 15 kt after midnight. Seas 8
ft subsiding to 3 ft after midnight.
.WED...NE wind 10 kt. Seas 3 ft.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU...SE wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 20 kt. Seas 5 ft.
.FRI...N wind 20 kt. Seas 5 ft.
.SAT THROUGH SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ141-201315-
Kachemak Bay-
358 PM AKDT Tue Oct 19 2021

.TONIGHT...SW wind 15 kt becoming SE 10 kt after midnight. Seas 4
ft subsiding to 2 ft after midnight. Rain.
.WED...Variable wind less than 10 kt. Seas 2 ft. Rain.
.WED NIGHT...Variable wind less than 10 kt becoming SW 10 kt after
midnight. Seas 2 ft.
.THU...SE wind 10 kt. Seas 2 ft.
.THU NIGHT...E wind 15 kt. Seas 2 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 2 ft.
.SUN...N wind 10 kt. Seas 2 ft.

$$

544 
FZAK51 PAFC 201157
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
357 AM AKDT Wed Oct 20 2021

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.

PKZ197-210015-
357 AM AKDT Wed Oct 20 2021
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A 978 mb low enters the southeastern Gulf this morning, then 
advances to 50 nm south of Cordova at 989 mb Wed night. The low then 
moves inland Thu morning. A front enters the western Gulf Thu 
afternoon.

$$

PKZ119-210015-
Cape Suckling to Cape Cleare-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 30 kt. Seas 14 ft.
.TONIGHT...NE wind 30 kt becoming S after midnight. Seas 15 ft.
.THU...S wind 20 kt. Seas 10 ft.
.THU NIGHT...E wind 20 kt. Seas 8 ft.
.FRI...E wind 30 kt. Seas 15 ft.
.SAT...E wind 30 kt. Seas 21 ft.
.SUN...E wind 25 kt. Seas 11 ft.

$$

PKZ120-210015-
Cape Cleare to Gore Point-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 15 kt. Seas 11 ft.
.TONIGHT...NW wind 20 kt. Seas 12 ft.
.THU...SW wind 15 kt. Seas 11 ft.
.THU NIGHT...E wind 20 kt. Seas 7 ft.
.FRI...E wind 30 kt. Seas 14 ft.
.SAT...NE wind 30 kt. Seas 18 ft.
.SUN...NE wind 25 kt. Seas 10 ft.

$$

PKZ121-210015-
Resurrection Bay-
357 AM AKDT Wed Oct 20 2021

.TODAY...N wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Rain.
.TONIGHT...N wind 15 kt. Seas 3 ft. Rain.
.THU...Variable wind 10 kt becoming S 15 kt in the afternoon. Seas
3 ft. Rain.
.THU NIGHT...N wind 10 kt. Seas 2 ft.
.FRI THROUGH SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ125-210015-
Prince William Sound-
357 AM AKDT Wed Oct 20 2021

...GALE WARNING TONIGHT...

.TODAY...NE wind 20 kt. Seas 4 ft. Rain.
.TONIGHT...N wind 20 kt becoming SE 40 kt after midnight. Seas 4
ft building to 9 ft after midnight. Rain.
.THU...SE wind 20 kt. Seas 4 ft. Rain.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 3 ft.
.SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ126-210015-
Port Valdez-
357 AM AKDT Wed Oct 20 2021

.TODAY...E wind 10 kt. Seas 2 ft. Rain.
.TONIGHT...E wind 10 kt increasing to 15 kt after midnight. Seas
3 ft. Rain.
.THU...E wind 10 kt. Seas 2 ft. Rain.
.THU NIGHT...E wind 10 kt. Seas 2 ft.
.FRI THROUGH SUN...E wind 15 kt. Seas 3 ft.

$$

PKZ127-210015-
Valdez Narrows-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY TONIGHT AND THURSDAY...

.TODAY...NE wind 20 kt. Seas 3 ft. Rain.
.TONIGHT...N wind 20 kt increasing to 30 kt after midnight. Seas
3 ft. Rain.
.THU...N wind 25 kt. Seas 3 ft. Rain.
.THU NIGHT...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SUN...N wind 20 kt. Seas 3 ft.

$$

PKZ128-210015-
Valdez Arm-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TODAY...NE wind 15 kt diminishing to 10 kt in the afternoon. Seas
3 ft. Rain.
.TONIGHT...NE wind 15 kt increasing to 30 kt after midnight. Seas
3 ft building to 5 ft after midnight. Rain.
.THU...NE wind 20 kt. Seas 4 ft. Rain.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 4 ft.
.SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-210015-
Passage Canal-
357 AM AKDT Wed Oct 20 2021

.TODAY...E wind 20 kt diminishing this morning then becoming W 10 kt
in the afternoon. Seas 2 ft. Rain.
.TONIGHT...W wind 10 kt increasing to 20 kt after midnight. Seas 3 
ft. Rain.
.THU...E wind 10 kt. Seas 2 ft. Rain.
.THU NIGHT...E wind 15 kt. Seas 2 ft.
.FRI THROUGH SUN...E wind 10 kt. Seas 2 ft.

$$

PKZ130-210015-
West of Barren Islands including Kamishak Bay-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TODAY...NW wind 20 kt. Seas 5 ft.
.TONIGHT...W wind 30 kt. Seas 8 ft.
.THU...W wind 15 kt becoming SE 20 kt in the afternoon. Seas 6 ft.
.THU NIGHT...E wind 30 kt. Seas 9 ft.
.FRI...NE wind 30 kt. Seas 10 ft.
.SAT...N wind 20 kt. Seas 5 ft.
.SUN...NW wind 15 kt. Seas 3 ft.

$$

PKZ131-210015-
Barren Islands East-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...Variable wind 10 kt becoming N 20 kt in the afternoon.
Seas 10 ft.
.TONIGHT...W wind 30 kt. Seas 13 ft.
.THU...SW wind 15 kt becoming SE 20 kt in the afternoon. Seas 11
ft.
.THU NIGHT...SE wind 25 kt. Seas 9 ft.
.FRI...E wind 25 kt. Seas 13 ft.
.SAT...NE wind 30 kt. Seas 18 ft.
.SUN...NE wind 25 kt. Seas 10 ft.

$$

PKZ132-210015-
Marmot Island to Sitkinak-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NW wind 30 kt. N of Dangerous Cape, E wind 15 kt becoming N
20 kt in the afternoon. Seas 9 ft.
.TONIGHT...NW wind 25 kt. Seas 12 ft.
.THU...SW wind 20 kt. Seas 11 ft.
.THU NIGHT...SE wind 35 kt. Seas 12 ft.
.FRI...SE wind 25 kt. Seas 19 ft.
.SAT...N wind 30 kt. Seas 19 ft.
.SUN...N wind 25 kt. Seas 11 ft.

$$

PKZ136-210015-
Chiniak Bay-
357 AM AKDT Wed Oct 20 2021

.TODAY...Variable wind less than 10 kt becoming NW 15 kt in the
afternoon. Seas 4 ft.
.TONIGHT...NW wind 15 kt becoming W 10 kt after midnight. Seas 3
ft.
.THU...Variable wind less than 10 kt becoming S 15 kt in the
afternoon. Seas 3 ft.
.THU NIGHT...SE wind 25 kt. Seas 10 ft.
.FRI...E wind 20 kt. Seas 6 ft.
.SAT...NE wind 20 kt. Seas 4 ft.
.SUN...N wind 15 kt. Seas 4 ft.

$$

PKZ137-210015-
Marmot Bay-
357 AM AKDT Wed Oct 20 2021

.TODAY...NE wind 10 kt becoming NW 15 kt in the afternoon. Seas
3 ft. Rain showers.
.TONIGHT...W wind 15 kt. Seas 3 ft.
.THU...SW wind 10 kt becoming SE 15 kt in the afternoon. Seas 2 ft
building to 4 ft in the afternoon.
.THU NIGHT...SE wind 25 kt. Seas 10 ft.
.FRI...E wind 20 kt. Seas 6 ft.
.SAT...NE wind 20 kt. Seas 4 ft.
.SUN...N wind 15 kt. Seas 4 ft.

$$

PKZ138-210015-
Shelikof Strait-
357 AM AKDT Wed Oct 20 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TODAY...N wind 20 kt. Seas 5 ft .
.TONIGHT...W wind 25 kt. Seas 6 ft.
.THU...SW wind 15 kt becoming SE 20 kt in the afternoon. Seas 4
ft.
.THU NIGHT...E wind 30 kt. Seas 8 ft.
.FRI...NE wind 25 kt. Seas 8 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 4 ft.

$$

PKZ139-210015-
Cook Inlet Kalgin Island to Point Bede-
357 AM AKDT Wed Oct 20 2021

.TODAY...NE wind 10 kt becoming N 15 kt in the afternoon. Seas 3
ft.
.TONIGHT...NW wind 10 kt becoming W 15 kt after midnight. Seas 3
ft.
.THU...SW wind 10 kt becoming SE 15 kt in the afternoon. Seas 3
ft.
.THU NIGHT...NE wind 25 kt. Seas 8 ft.
.FRI...NE wind 30 kt. Seas 10 ft.
.SAT...N wind 15 kt. Seas 4 ft.
.SUN...W wind 10 kt. Seas 2 ft.

$$

PKZ140-210015-
Cook Inlet North of Kalgin Island-
357 AM AKDT Wed Oct 20 2021

.TODAY...NE wind 10 kt. Seas 3 ft.
.TONIGHT...Variable wind less than 10 kt becoming NW 10 kt after
midnight. Seas 2 ft.
.THU...S wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 20 kt. Seas 5 ft.
.FRI...NE wind 20 kt. Seas 5 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SUN...S wind 10 kt. Seas 3 ft.

$$

PKZ141-210015-
Kachemak Bay-
357 AM AKDT Wed Oct 20 2021

.TODAY...NE wind 10 kt. Seas 2 ft. Rain.
.TONIGHT...NW wind 10 kt becoming W 15 kt after midnight. Seas 2
ft building to 4 ft after midnight.
.THU...SW wind 10 kt becoming E 15 kt in the afternoon. Seas 2 ft.
.THU NIGHT...E wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 3 ft.
.SUN...N wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
443 PM AKDT Mon Oct 18 2021

.ANALYSIS AND UPPER LEVELS...

A broad mid to upper trough wrapped to a diffused upper low near
Kodiak will continue to bring steady light to moderate rain over
Kodiak Island and the northern Gulf, including Western Prince
William Sound. A barrier jet meandering over the northern Gulf has
generated strong easterly winds with high end gales near
Middleton Island and mainly south of Prince William Sound today.
Meanwhile, a vast upper ridge runs across the Bering to Southwest
Alaska then turns east through Southcentral to beyond Wrangell
Mountains. Multiple shortwaves over the Alaska Peninsula and
across the Gulf enhances the potential for increased rain, clouds
and gusty winds in those areas.

&&

.MODEL DISCUSSION...

Synoptic agreement in the short term is pretty good this
afternoon. Guidance has converged and agrees on how the
aforementioned diffuse Gulf low will elongate before sliding north
into Prince William Sound. Translated down to the surface, this
low will move inland near Seward tomorrow morning. This is a shift
from previous guidance that now places the low farther west. This
track change also increases winds along Turnagain Arm, a point
where all models are agreeing. Deeper into the work week,
guidance, surprisingly, tells a very similar story with the next
system moving in from Japan. By forecast hours 72-78, there are
minor placement errors amongst the big model members, with the
overall trend that seems to be set with a strong low moving into
the Bering in that time.

&&

.AVIATION...

PANC...VFR conditions will persist, with gentle northerly winds
continuing through today and Tue morning. Tue evening, Turnagain
Arm winds will be increasing. For the majority of the event, winds
should remain off of the airfield, but there may be a window at
12z on the 20th where winds may bend into the airfield for a 3-6
hour period. There is a low probability that ceilings may lower
towards low end MVFR levels around the same timeframe.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Tonight through Thursday afternoon)...

A nearly stationary front in the Gulf will continue to bring high
end gale force winds, and elevated seas at times near the coastal
areas before subsiding to small crafts by Tuesday night. A moist,
easterly flow pattern associated with the frontal boundary will
also keep cool and wet conditions ongoing over the next couple of
days especially in Prince William Sound.

Meanwhile, an area of low pressure will form along the front and
move south of Cordova tonight. The latest operational model runs
are coming into decent agreement with a more westward track of
the low by Tuesday evening, before weakening and moving across
the Kenai Peninsula by Wednesday morning. As it does so, a
tightening pressure gradient will ramp up winds across the
forecast area with stronger gusts expected over the hillside and
higher elevations.

Additionally, the low will push some of the precipitation further
inland beginning on Tuesday with rain/snow mix in the valleys and
snow in the surrounding elevations. The Matanuska Valley,
Anchorage Bowl, and western Kenai Peninsula will remain mostly dry
with the downslope easterly flow, but a rain or two cannot
completely be ruled out especially for Wednesday afternoon and
evening if the winds weaken and shift more southerly. Thereafter,
a secondary low will form in the eastern Gulf on Wednesday
evening, bringing another round of moderate to heavy rain in PWS
and the eastern Kenai Peninsula through Thursday afternoon.

&&

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

A low in the northwestern Bering will bring unsettled weather to
the Southwest through Wednesday. Its front is already beginning to
push ashore in the Kuskokwim Delta region this evening, with the
first returns already visible on the Bethel radar. Precipitation
should begin as snow with temperatures in the Lower Kuskokwim
Valley and Delta region hovering around or below freezing.
However, warm air advection is expected with the passage of the
front. Snow should turn to rain as the front progresses inland
through Tuesday afternoon. Further south, at locations like
Dillingham and King Salmon, warm air aloft combined with a warmer
pre-existing airmass will keep precipitation as rain. Overall,
precipitation is expected to be light with minimal snow
accumulations. Behind the front, expect drier conditions and gradually
cooling temperatures Wednesday and Thursday.

&&

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

Tonight, a series of fronts associated with a low in the
northwestern Bering Sea track eastward across the Aleutian Chain,
bringing showers and gusty winds. Gale force winds enhanced by
cold air advection behind the fronts will sweep through the
Aleutians, beginning in the west tonight and reaching the eastern
islands Tuesday night. As the intensity of the cold air advection
diminishes, winds will follow suit through Wednesday morning. Snow
or rain/snow showers are possible over the Pribilofs on Tuesday
night with the advancing cold air. However, rain showers are
expected for the remainder of the Aleutians as heat from the
warmer ocean waters modifies the air mass. Wednesday night, a
second low approaches the western Aleutians from the North
Pacific. This low will have the potential to produce storm-force
winds as it crosses the islands into the Bering.

&&

.MARINE (Days 3 through 5/Thursday through Saturday)...

Bering/Aleutians

Forecast confidence is moderate during the 3-5 day period as a
strong low pressure system moves through the southern Bering Sea
on Thursday and Friday. Minor differences exist between guidance
with respect to the placement and intensity of this low. There is
high confidence that widespread gale force winds will occur during
this period. In addition to the strong winds, large long period
northwesterly swell is expected along the coastal waters on the
north side of the Aleutian Islands Thursday and Friday. These
winds and seas will gradually ease and abate on Saturday.

Gulf of Alaska

Forecast confidence remains above average for Thursday with winds
remaining under gale force and no high seas. Confidence decreases
on Friday as the next low moves in from the North Pacific. Gale
force winds are possible along the coastal waters throughout the
northern Gulf on Friday and Saturday.

&&

.LONG TERM FORECAST (Days 4 through 7/Friday through Monday)...

A cloudy, cool and wet pattern is expected for Southcentral Friday
through Monday as upper-level troughing extends from the northern
Bering Sea into the central Gulf. This orientation of the upper
trough will allow for moisture to enter Southcentral as the
trough-axis remains southwest of the Kenai Peninsula and thus
resulting in broad south-southeasterly flow from the Gulf. With
respect to precipitation type, the chance for snow increases with
elevation.

The Bering/Aleutians will be in a cloudy and cool pattern as broad
upper level troughing continues to extend across the region.
Strong northwesterly gap winds are expected in the eastern
Aleutians and western Alaska Penunsula on Friday and Saturday in
the wake of a strong low pressure system moving into the Gulf.
These winds will eae Sunday and Monday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale Warning: 119-120, 125, 128, 131, 140, 155, 170-179,
                       185, 351, 411-414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...SS
SOUTHCENTRAL ALASKA...MF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CQ/PS
MARINE/LONG TERM...ED