Small Craft Advisory 691, NWS Anchorage, AK

950 
FZAK51 PAFC 030008
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
408 PM AKDT Thu Sep 2 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.

PKZ197-031245-
408 PM AKDT Thu Sep 2 2021
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A trough remains over the northern Gulf through Fri night then 
develops a 999 mb low 70 nm south of Montague Island Sat afternoon. 
A developing 1004 mb North Pacific low 220 nm south of Adak deepens 
to 994 mb as it swings to the eastern Gulf near Cross Sound Sat 
afternoon.

$$

PKZ119-031245-
Cape Suckling to Cape Cleare-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...SE wind 15 kt. Seas 7 ft. Rain showers.
.FRI...E wind 15 kt. Seas 5 ft.
.FRI NIGHT...NE wind 15 kt. Seas 5 ft. Rain.
.SAT...E wind 15 kt. Seas 5 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 4 ft.
.SUN THROUGH MON...SE wind 20 kt. Seas 4 ft.
.TUE...NE wind 20 kt. Seas 4 ft.

$$

PKZ120-031245-
Cape Cleare to Gore Point-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...SE wind 15 kt. Seas 7 ft. Rain.
.FRI...SE wind 15 kt. Seas 5 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 4 ft.
.SAT...N wind 15 kt. Seas 4 ft.
.SAT NIGHT...NE wind 15 kt. Seas 4 ft.
.SUN...Variable wind 10 kt. Seas 4 ft.
.MON...E wind 20 kt. Seas 4 ft.
.TUE...NE wind 20 kt. Seas 4 ft.

$$

PKZ121-031245-
Resurrection Bay-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 10 kt in the evening becoming variable less than
10 kt. Gusts to 20 kt in the evening. Seas 2 ft. Rain.
.FRI...Variable wind 10 kt becoming S in the afternoon. Seas 2 ft.
Widespread rain showers.
.FRI NIGHT...Variable wind less than 10 kt. Seas 2 ft. Widespread
rain showers.
.SAT...S wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN...S wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...N wind 10 kt. Seas 2 ft.

$$

PKZ125-031245-
Prince William Sound-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...E wind 20 kt. Seas 3 ft. Widespread rain showers.
.FRI...SE wind 15 kt becoming NE 10 kt in the afternoon. Seas 3
ft. Widespread rain showers.
.FRI NIGHT...Variable wind less than 10 kt becoming N 10 kt after
midnight. Seas 2 ft. Widespread rain showers.
.SAT...N wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 10 kt. Seas 2 ft.
.TUE...N wind 10 kt. Seas 2 ft.

$$

PKZ126-031245-
Port Valdez-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Widespread
rain showers.
.FRI...Variable wind less than 10 kt becoming W 10 kt in the
afternoon. Seas 2 ft. Widespread rain showers.
.FRI NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain.
.SAT THROUGH TUE...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-031245-
Valdez Narrows-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...Variable wind 10 kt becoming N 15 kt after midnight.
Seas 3 ft. Widespread rain showers.
.FRI...N wind 10 kt becoming S in the afternoon. Seas 2 ft.
Widespread rain showers.
.FRI NIGHT...NE wind 10 kt becoming N after midnight. Seas 2 ft. 
Rain.
.SAT...SW wind 10 kt. Seas 2 ft.
.SAT NIGHT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...NE wind 10 kt. Seas 2 ft.
.TUE...Variable wind 10 kt. Seas 2 ft.

$$

PKZ128-031245-
Valdez Arm-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...NE wind 15 kt. Gusts to 25 kt in the evening. Seas 2 ft. 
Widespread rain showers.
.FRI...NE wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft. Widespread rain showers.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SUN THROUGH MON...SW wind 10 kt. Seas 2 ft.
.TUE...Variable wind 10 kt. Seas 2 ft.

$$

PKZ129-031245-
Passage Canal-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...E wind 20 kt diminishing to 10 kt after midnight. Gusts to
30 kt near Whittier in the evening. Seas 2 ft. Rain.
.FRI...E wind 10 kt. Seas 2 ft. Widespread rain showers.
.FRI NIGHT...E wind 10 kt. Seas 2 ft. Widespread rain showers.
.SAT AND SAT NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 10 kt. Seas 2 ft.
.TUE...W wind 10 kt. Seas 2 ft.

$$

PKZ130-031245-
West of Barren Islands including Kamishak Bay-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 15 kt. Seas 4 ft. Rain.
.FRI...E wind 15 kt. Seas 4 ft. Rain showers.
.FRI NIGHT...SE wind 15 kt. Seas 2 ft.
.SAT AND SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN THROUGH TUE...Variable wind 10 kt. Seas 3 ft.

$$

PKZ131-031245-
Barren Islands East-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 15 kt. Seas 7 ft. Rain.
.FRI...SE wind 15 kt. Seas 5 ft.
.FRI NIGHT...SE wind 15 kt. Seas 4 ft.
.SAT...Variable wind 10 kt. Seas 4 ft.
.SAT NIGHT...NW wind 15 kt. Seas 3 ft.
.SUN...Variable wind 10 kt. Seas 4 ft.
.MON...NE wind 15 kt. Seas 4 ft.
.TUE...N wind 20 kt. Seas 4 ft.

$$

PKZ132-031245-
Marmot Island to Sitkinak-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 15 kt. Seas 6 ft.
.FRI AND FRI NIGHT...SW wind 15 kt. Seas 5 ft.
.SAT AND SAT NIGHT...Variable wind 10 kt. Seas 4 ft.
.SUN...W wind 15 kt. Seas 4 ft.
.MON THROUGH TUE...N wind 20 kt. Seas 4 ft.

$$

PKZ136-031245-
Chiniak Bay-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...SE wind 10 kt. Seas 3 ft. Rain showers.
.FRI...Variable wind less than 10 kt. Seas 3 ft.
.FRI NIGHT...Variable wind less than 10 kt becoming NW 10 kt after
midnight. Seas 2 ft.
.SAT...NW wind 10 kt. Seas 3 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 1 ft.
.SUN...Variable wind less than 10 kt. Seas 3 ft.
.MON...NE wind 10 kt. Seas 3 ft.
.TUE...N wind 15 kt. Seas 2 ft.

$$

PKZ137-031245-
Marmot Bay-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...Variable wind less than 10 kt becoming SE 10 kt after
midnight. Seas 3 ft. Rain showers.
.FRI...Variable wind less than 10 kt. Seas 3 ft.
.FRI NIGHT...Variable wind less than 10 kt becoming NW 10 kt after
midnight. Seas 2 ft.
.SAT...W wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 3 ft.
.MON...NE wind 10 kt. Seas 3 ft.
.TUE...N wind 15 kt. Seas 2 ft.

$$

PKZ138-031245-
Shelikof Strait-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 15 kt in the evening becoming variable 10 kt.
Seas 3 ft. Rain.
.FRI...Variable wind 10 kt. Seas 2 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 3 ft.
.SAT...SW wind 15 kt. Seas 3 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN...W wind 15 kt. Seas 3 ft.
.MON THROUGH TUE...N wind 15 kt. Seas 3 ft.

$$

PKZ139-031245-
Cook Inlet Kalgin Island to Point Bede-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...S wind 20 kt becoming E 10 kt after midnight. Seas 5 ft
subsiding to 2 ft after midnight. Rain.
.FRI...NE wind 10 kt increasing to 15 kt in the afternoon. Seas 3 
ft. Rain.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 1 ft.
.SAT NIGHT...SW wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...SW wind 10 kt. Seas 2 ft.
.TUE...NW wind 10 kt. Seas 2 ft.

$$

PKZ140-031245-
Cook Inlet North of Kalgin Island-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...E wind 15 kt. Seas 4 ft subsiding to 2 ft after
midnight. Rain.
.FRI...NE wind 15 kt diminishing to 10 kt in the afternoon. Seas
3 ft. Rain.
.FRI NIGHT AND SAT...Variable wind less than 10 kt. Seas 1 ft.
.SAT NIGHT...SW wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...SW wind 10 kt. Seas 3 ft.
.TUE...NW wind 10 kt. Seas 2 ft.

$$

PKZ141-031245-
Kachemak Bay-
408 PM AKDT Thu Sep 2 2021

.TONIGHT...SW wind 15 kt becoming variable less than 10 kt after 
midnight. Seas 2 ft. Rain.
.FRI...Variable wind less than 10 kt. Seas 2 ft. Widespread rain
showers.
.FRI NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain showers.
.SAT THROUGH TUE...Variable wind less than 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
515 PM AKDT Wed Sep 1 2021

.ANALYSIS AND UPPER LEVELS...

Generally wet conditions have triumphed across Southcentral this
evening thanks to the passage of a morning wave of low pressure
now making its way into Southwest. Current composite reflectivity
reveals a swath of precipitation occurring from Bristol Bay
northeastward into the MatSu in response to this initial wave.
Areas immediately west of the Chugach Mountains have already
experienced some clearing thanks to downward sloping of easterly
cross barrier winds. Otherwise, current rainfall is slowly
drifting westward toward the Kuskokwim Delta where lighter
precipitation is also underway near Bethel. Dense cloud cover is
noted per satellite over the gulf as a second wave of low pressure
is now lifting northward into the gulf coast. Easterly surface
winds are increasing across the gulf coast as the pressure
gradient tightens and a barrier jet is gradually materializing.
Middleton Island surface observations show gusts to 40 knots are
already in progress. Further west northeasterly winds gusting over
40 knots are noted across the Barren Islands. A more broad area
of troughing located over the Bering is keeping much of the region
under continued low-level stratus and fog.

&&

.MODEL DISCUSSION...

Model guidance is in good agreement with the upper- level
features of the atmosphere this evening. Global models depict two
waves of low pressure consolidating into an open wave trough over
the Kuskokwim Delta with corresponding rain chances persisting
into the weekend. Models remain keen on this trough exiting the
gulf to the east while reintroducing northerly flow back into the
Bering over the latter half of the weekend. More uncertainty
develops by early next week. The GFS has a piece of energy
breaking off of the polar jet stream, resulting in a small cutoff
low over Southcentral. Meanwhile, the EC keeps the polar jet
further north with a more substantial low developing over the Gulf
in association with the subtropical jet stream. As either
scenario would introduce considerably different impacts to
Southcentral confidence remains very low beyond 72 hours.

&&

.AVIATION...

PANC...VFR conditions to persist through tonight into Thursday as
as a wave of low pressure rotates counterclockwise into the
Kuskokwim Delta from the Gulf. While rain chances diminished
quickly this afternoon across PANC, rain is expected to become
increasingly likely later tonight into Thursday morning. It is
possible MVFR conditions could develop at times during this
rainfall. Otherwise, confidence is increasing that Turnagain winds
will develop later on Thursday after northerly morning winds to
near 10 knots shift to a southeasterly direction and increase in
speed through Thursday evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Tonight through Saturday)...

The fall-like wet weather pattern is well underway as a broad
longwave trough sets up over the eastern Bering Sea. A pair of
North Pacific lows rounding the base of trough will be the main
drivers affecting much of Southcentral in the next couple of days.
The first one is slowly weakening as it tracks northwestward of
the AKPEN to Southwest, AK. Meanwhile, rain developed today from
eastern Kenai Peninsula north across Anchorage Bowl to the Mat-Su
Valleys, and coastal areas of Prince William Sound. This is
response to an upper level wave coupled with a warm front
extending from the low center that moved inland from the north
Gulf coast. In addition to the rain associated with this system, a
barrier jet has set up from the southeastern Kenai Peninsula
coast to the Barren Islands with widespread high end gales to low
end storm force winds.

The next low pressure system and associated front will follow on
the heels of this first one that is currently moving up across the
central Gulf. This system will reinforce the barrier jet along
the north Gulf coast the rest of tonight through tomorrow with
high end gales to storm force winds along the north Gulf coast.
Gusty, southeasterly gap winds will develop out ahead of the
front beginning tomorrow afternoon and will continue through late
Thursday night over Turnagain Arm, Knik River Valley, and the
Copper River Valley in response to a coastal ridge and pressure
gradient strengthening. The associated front with a deep fetch of
tropical moisture will bring another round of rain along Prince
William Sound and then spreading inland tonight into Thursday
morning.

The broad troughing pattern over the Bering Sea will continue
sending a series of upper level waves, and keeping the cool,
cloudy, and rainy conditions ongoing through the rest of the week.
The last model guidance has the bulk of the moisture and
precipitation along the coast, with scattered rain further inland.

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

Rain is working its way through Southwest AK today, rotating in
from the southeast off a low the Western Gulf of Alaska. A
smaller, secondary low will develop off the energy moving into
Southwest Alaska and linger in the Bristol Bay area for the next
couple of days. This will keep weather unsettled and provide a
high likelihood of continued rain for Southwest AK. This weak low
will exit Saturday and is expected to be followed by northwest
winds. These winds will not offer much of a reprieve, as they
should be advecting moisture in off the Bering, keeping cloudy and
rainy conditions in place. Models generally agree, however the
GFS is an outlier with low placement, so this was not factored
into the forecast today. Otherwise, moderate to high confidence in
the forecast. Expect wet weather to continue through the weekend.

&&

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

The Bering Sea and Aleutians remain under long wave toughing which
will keep weather active through the end of the week. On the
surface, a broad and disorganized low pressure continues to make
for widespread areas of low cloud cover and rain showers. Ridging
does develop in the very Western Bering on Saturday. However,
expect cloud cover to continue under this ridge.

&&

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

Expect winds less than 35 kts and seas less than 20 ft for the
Day 3 through 5 period.

&&

.LONG TERM FORECAST (Days 4 through 7/Sunday through Wednesday)...

Relatively good agreement amongst the models for upper level
troughing, with weak surface reflection, moving across Southern
Alaska Sunday and Monday, bringing rounds of rain showers to the
Southern Mainland. The surface low moves off to the Southeast by
Tuesday, followed up immediately by upper level ridging across
Southwest and Southcentral. Weak upper level troughing moves
across the Bering/Aleutians behind the ridge, impacts are likely
to be minimal. Expect cool, wet, cloudy conditions transitioning
to warmer, drier, clearer conditions through the early portions of
next week.

There is still pretty low confidence for a low pressure system
moving into the Bering early/mid-week and how much moisture it
will carry. The GFS, so far, is the strongest and has a decent
moisture feed associated with it, looking to produce more
precipitation than the other solutions.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storm Warning 119.
		 Gale warning 120 125 130 131 139.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...MF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BJB
MARINE/LONG TERM...KM