Small Craft Advisory 169, NWS Anchorage, AK

681 
FZAK52 PAFC 251235
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
335 AM AKST Thu Feb 25 2021

Coastal Waters Forecast for Southwest Alaska+Bristol Bay+The
Alaska Peninsula Waters and the Aleutian Islands up to 100 nm out.

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.

PKZ199-260130-
335 AM AKST Thu Feb 25 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 986 mb low 180 nm southwest of Attu moves 30 nm west of Attu at
992 mb Thu afternoon. The low then moves 220 nm north of Shemya 
at 996 mb Fri afternoon.

$$

PKZ150-260130-
South of the AK Peninsula Sitkinak to Castle Cape-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...W wind 30 kt. Seas 15 ft. Rain.
.TONIGHT...SW wind 30 kt. Seas 14 ft.
.FRI...SW wind 30 kt. Seas 12 ft.
.FRI NIGHT...W wind 25 kt. Seas 13 ft.
.SAT THROUGH SUN...W wind 45 kt. Seas 19 ft.
.MON...SW wind 40 kt. Seas 20 ft.

$$

PKZ155-260130-
South of the AK Peninsula Castle Cape to Cape Sarichef-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...SW wind 25 kt increasing to 35 kt 
in the afternoon. Seas 15 ft. Rain.
.TONIGHT...SW wind 30 kt. Seas 15 ft.
.FRI...SW wind 30 kt. Seas 13 ft. Rain.
.FRI NIGHT...W wind 20 kt. Seas 13 ft.
.SAT...W wind 35 kt. Seas 15 ft.
.SUN...SW wind 40 kt. Seas 23 ft.
.MON...SW wind 45 kt. Seas 25 ft.

$$

PKZ160-260130-
Bristol Bay-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...W wind 35 kt diminishing to 25 kt in the afternoon. 
Seas in ice free waters 11 ft.
.TONIGHT...SW wind 25 kt. Seas in ice free waters 6 ft. 
Rain and snow.
.FRI...S wind 20 kt. Seas in ice free waters 6 ft.
.FRI NIGHT...SW wind 25 kt. Seas in ice free waters 8 ft.
.SAT...W wind 40 kt. Seas in ice free waters 11 ft.
.SUN...NE wind 35 kt. Seas in ice free waters 10 ft.
.MON...SW wind 35 kt. Seas in ice free waters 11 ft.

$$

PKZ165-260130-
Port Heiden to Cape Sarichef-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...S wind 30 kt. From Port Moller E, SW wind 30 kt 
becoming S 20 kt in the afternoon. Seas 13 ft. Rain.
.TONIGHT...S wind 30 kt. Seas 10 ft.
.FRI...S wind 25 kt. Seas 9 ft.
.FRI NIGHT...W wind 25 kt. Seas 10 ft.
.SAT...NW wind 30 kt. Seas 12 ft.
.SUN...S wind 40 kt. Seas 23 ft.
.MON...SW wind 45 kt. Seas 25 ft.

$$

PKZ170-260130-
Cape Sarichef to Nikolski Bering Side-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...S wind 35 kt. Seas 12 ft. Rain.
.TONIGHT...S wind 30 kt. Seas 12 ft. Rain.
.FRI...S wind 30 kt. Seas 10 ft. Rain.
.FRI NIGHT...W wind 30 kt. Seas 9 ft.
.SAT...W wind 30 kt. Seas 13 ft.
.SUN...S wind 45 kt. Seas 29 ft.
.MON...SW wind 45 kt. Seas 32 ft.

$$

PKZ171-260130-
Unalaska Bay-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...S wind 15 kt becoming SW 25 kt in the afternoon. 
Seas 4 ft. Rain and snow.
.TONIGHT...S wind 20 kt. Seas 3 ft. Rain.
.FRI...S wind 20 kt. Seas 3 ft. Rain.
.FRI NIGHT...SW wind 15 kt. Seas 2 ft.
.SAT...W wind 30 kt. Seas 9 ft.
.SUN...S wind 30 kt. Seas 5 ft.
.MON...SW wind 35 kt. Seas 5 ft.

$$

PKZ172-260130-
Cape Sarichef to Nikolski Pacific Side-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...S wind 35 kt. Seas 17 ft. Rain.
.TONIGHT...SW wind 30 kt. Seas 17 ft.
.FRI...S wind 30 kt becoming W 20 kt in the afternoon. 
Seas 14 ft. Rain.
.FRI NIGHT...W wind 30 kt. Seas 13 ft.
.SAT...W wind 35 kt. Seas 16 ft.
.SUN THROUGH MON...SW wind 45 kt. Seas 28 ft.

$$

PKZ173-260130-
Nikolski to Seguam Island Bering Side-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...SW wind 35 kt diminishing to 25 kt in the afternoon. 
Seas 13 ft. Rain.
.TONIGHT...SW wind 25 kt. Seas 11 ft. Rain and snow.
.FRI...W wind 25 kt. Seas 9 ft.
.FRI NIGHT...W wind 35 kt. Seas 14 ft.
.SAT...W wind 35 kt. Seas 16 ft.
.SUN...S wind 45 kt. Seas 33 ft.
.MON...SW wind 45 kt. Seas 33 ft.

$$

PKZ174-260130-
Nikolski to Seguam Island Pacific Side-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...S wind 40 kt. Seas 19 ft. Rain.
.TONIGHT...S wind 30 kt. Seas 19 ft. Rain.
.FRI...SW wind 30 kt becoming W 20 kt in the afternoon. 
Seas 16 ft.
.FRI NIGHT...W wind 30 kt. Seas 15 ft.
.SAT...W wind 35 kt. Seas 18 ft.
.SUN THROUGH MON...SW wind 45 kt. Seas 31 ft.

$$

PKZ175-260130-
Seguam Island to Adak Bering Side-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...S wind 25 kt. Seas 9 ft.
.TONIGHT...S wind 20 kt. Seas 9 ft.
.FRI...SW wind 25 kt. Seas 9 ft.
.FRI NIGHT...W wind 35 kt. Seas 14 ft.
.SAT...SW wind 50 kt. Seas 15 ft.
.SUN...SW wind 50 kt. Seas 34 ft.
.MON...SW wind 45 kt. Seas 35 ft.

$$

PKZ176-260130-
Seguam Island to Adak Pacific Side-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...SW wind 35 kt diminishing to 25 kt in the afternoon.
Seas 19 ft. Rain and snow.
.TONIGHT...SW wind 20 kt. Seas 18 ft. Rain and snow.
.FRI...SW wind 25 kt. Seas 15 ft.
.FRI NIGHT...W wind 30 kt. Seas 17 ft.
.SAT...SW wind 50 kt. Seas 19 ft.
.SUN...SW wind 50 kt. Seas 31 ft.
.MON...SW wind 45 kt. Seas 34 ft.

$$

PKZ177-260130-
Adak to Kiska-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...SW wind 30 kt. Seas 14 ft Bering side...21 ft Pacific side.
.TONIGHT...SW wind 30 kt. Seas 19 ft.
.FRI...W wind 30 kt. Seas 16 ft.
.FRI NIGHT...W wind 30 kt. Seas 15 ft.
.SAT...S wind 55 kt. Seas 27 ft.
.SUN...SW wind 50 kt. Seas 38 ft.
.MON...SW wind 45 kt. Seas 35 ft.

$$

PKZ178-260130-
Kiska to Attu-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TODAY...

.TODAY...S wind 35 kt. Seas 22 ft. Widespread snow showers.
.TONIGHT...SW wind 30 kt. Seas 21 ft.
.FRI...W wind 30 kt. Seas 14 ft.
.FRI NIGHT...W wind 30 kt. Seas 14 ft.
.SAT...S wind 55 kt. Seas 29 ft.
.SUN...SW wind 55 kt. Seas 39 ft.
.MON...SW wind 40 kt. Seas 31 ft.

$$

PKZ179-260130-
Pribilof Islands Near Shore Waters-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...S wind 30 kt. Seas 13 ft. Rain and snow.
.TONIGHT...SW wind 25 kt diminishing to 15 kt after midnight. 
Seas 10 ft. Rain showers and snow showers.
.FRI...S wind 15 kt becoming W 30 kt in the afternoon. Seas 11 ft.
Rain and snow.
.FRI NIGHT...NW wind 20 kt. Seas 9 ft.
.SAT...N wind 20 kt. Seas 8 ft.
.SUN...S wind 40 kt. Seas 27 ft.
.MON...W wind 35 kt. Seas 29 ft.

$$

PKZ180-260130-
Kuskokwim Delta and Etolin Strait-
335 AM AKST Thu Feb 25 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...SW wind 30 kt diminishing to 20 kt in the afternoon. 
Seas in ice free waters 12 ft. Snow with rain.
.TONIGHT...SE wind 25 kt. Seas in ice free waters 8 ft. Snow.
.FRI...S wind 20 kt increasing to 30 kt in the afternoon. 
Seas in ice free waters 8 ft. Snow and rain.
.FRI NIGHT...W wind 30 kt. Seas in ice free waters 9 ft.
.SAT...NW wind 30 kt. Seas in ice free waters 8 ft.
.SUN...E wind 35 kt. Seas in ice free waters 13 ft.
.MON...SW wind 35 kt. Seas in ice free waters 15 ft.

$$

PKZ181-260130-
North and West of Nunivak Island-
335 AM AKST Thu Feb 25 2021

...BRISK WIND ADVISORY TONIGHT AND FRIDAY...

.TODAY...NW wind 15 kt.
.TONIGHT...NE wind 25 kt.
.FRI...NE wind 30 kt.
.FRI NIGHT...N wind 30 kt.
.SAT...NW wind 25 kt.
.SUN...E wind 35 kt.
.MON...N wind 30 kt.

$$

PKZ185-260130-
Saint Matthew Island Waters-
335 AM AKST Thu Feb 25 2021

...GALE WARNING TONIGHT AND FRIDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY...

.TODAY...NE wind 20 kt E of Saint Matthew Island... NE 30 kt W of
Saint Matthew Island. Seas in ice free waters 10 ft. Heavy
freezing spray. Snow.
.TONIGHT...NE wind 30 kt E of Saint Matthew Island... NE 35 kt W
of Saint Matthew Island. Seas in ice free waters 13 ft. Heavy 
freezing spray.
.FRI...NE wind 30 kt E of Saint Matthew Island... NE 35 kt W of
Saint Matthew Island. Seas in ice free waters 13 ft. Heavy
freezing spray.
.FRI NIGHT...N wind 30 kt. Seas in ice free waters 11 ft.
.SAT...N wind 40 kt. Seas in ice free waters 8 ft.
.SUN...E wind 55 kt. Seas in ice free waters 22 ft.
.MON...NW wind 45 kt. Seas in ice free waters 28 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
452 AM AKST Wed Feb 24 2021

.ANALYSIS AND UPPER LEVELS...

The upper level pattern features troughing from the Being to the
Gulf Of Alaska with a major shortwaves over the Alaska Peninsula
and south of Attu Island. At the surface there is a low entering
the Western Gulf Of Alaska, a decaying low near St Matthew island
and a mature low south of Shemya. On satellite imagery the ASCAT
(Advanced Scatterometer) passes have detected gale force winds
south of the western Aleutians and south of Kodiak. On another
channel of satellite imagery, there is a discernible moisture
fetch that extends from south of Kodiak to the Central Pacific
near Hawaii. The radars at Bethel (PABC), King Salmon (PAKC),
Kenai (PAHG) and Middleton Island (PAIH) have been active
overnight and early this morning. Warmer air has advected into
the Anchorage Bowl. This morning, the 12Z or 3 AM AKST observation
at Ted Stevens Intl Airport was 17 degrees warmer (in Fahrenheit)
than it was 24 hours ago.

&&

.MODEL DISCUSSION...
Models are in good synoptic agreement the next 48 hrs.  The ECMWF
continues to have the best run to run continuity. The biggest
forecast challenge will be determining the start and the stop
times of the next waves of precipitation.

&&

.AVIATION...
PANC...More snow is expected this TAF package. The radar is
actively being monitored and amendments will be made as needed.
Expect the cigs and visibility to change flight categories.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3/Today
through Friday night)...

A strengthening low over the southern Gulf will track east-
northeast across the Gulf today. This will keep the bulk of wind
and heavy precipitation confined to the Gulf and Kodiak Island.
Kodiak will start out with primarily rain this morning, but slight
cooling on the back side of the low will lead to a mix with or
changeover to snow before precipitation tapers off this afternoon.
Precipitation will remain all snow for Southcentral and will
mostly be light, with the exception of some heavier precipitation
right along the Gulf and Prince William Sound coasts.

Strengthening easterly flow across the Kenai and Chugach Mountains
will lead to a downslope hole from the western Kenai to Anchorage
and the Matanuska Valley by about mid morning. However, these
winds will quickly die down as the low exits eastward late this
afternoon. A weak negatively tilted upper level trough will then
cause snow to overspread the region this afternoon through evening.
Generally expect light accumulation, with locally heavier amounts
on west-facing slopes as low level southwesterly flow and weak
cold air advection develop overnight. Snow will linger Thursday
across the Copper River Basin as well as west-facing mountains as
a series of weak waves move through aloft and strong low level
westerly flow persists. However, generally expect a drying trend
across the region.

Strong westerly flow overtop of a ridge situated over the North
Pacific combined with accompanying pressure rises behind the
exiting low will lead to widespread strong westerly winds across
the Gulf waters on Thursday. Pressure gradients are favorable
for these winds to get into Kachemak Bay and Homer. Snow also
looks likely as an upper wave moves through Thursday morning.
Thus, there could be a period of low visibilities in snow and
blowing snow. However, expect snowfall in any one location to
be short-lived.

A building ridge will keep things mostly dry Thursday through
Friday. Passing clouds will keep temperatures from dropping very
much. Progressive upper level flow will then bring another storm
into the region late Friday afternoon through Friday night. With
a more amplified upper level flow, warmer air will make it
farther north, possibly resulting in rain as far north as the
southern Kenai Peninsula. The rest of Southcentral can expect
another quick shot of snow.

&&

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

Snowfall will continue across much of the Southwest Mainland
today as a front pushes farther inland throughout the day. The
snow will become more showery and begin to diminish from west to
east starting late this morning into the afternoon. However, a
second wave of precipitation will move into interior Bristol Bay
this evening, bringing another quick shot of snowfall overnight
into early Thursday morning. Snow accumulation with this second
wave should be minimal compared to the system currently moving
through.

The showery pattern will persists through Friday afternoon when
the next organized system approaches the coast. There is still
some uncertainty in timing and places of the heaviest QPF, but it
looks like there could be the potential for blowing snow over the
Kuskokwim Delta on Friday as stronger winds move into this area.
Warmer temperatures across the southern mainland will keep areas
in a mix of rain/snow or all rain in this pattern through the
start of the weekend.

&&

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

The unsettled weather persists across the Bering and Aleutians
as a front keeps widespread gales and precipitation along the
southern Bering and Aleutian Chain. This system will track
eastward toward the Southwest Mainland through Thursday, with
a second, weaker low pressure system entering the western Bering
by Thursday afternoon.

A low in the North Pacific will lift northward late Thursday,
tracking towards the Pribilofs by early Friday morning. Models
have shifted the track slightly for the low position, but the
potential for storm force winds near and just east of the
Pribilofs is still possible. Temperatures for the Pribilofs should
remain above freezing with this system. However, should the
temperatures drop below freezing, blowing snow could be possible
in higher winds.

&&

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

Bering: There is increasing confidence that a gale force low will
track into the central Bering Friday and continue to the
northeast. There is potential for storm force winds to develop
with this low as it will strengthen while it traverses the Bering
through early Saturday. On the heels of this low is a much larger
storm force low moving into the western Bering for Sunday. There
is impressive model consistency with this next low, which leads to
increased confidence that storm force winds will spread across
the Bering beginning late Saturday night and lasting through
Monday.

Gulf of Alaska: There is moderate confidence that a gale force
front will traverse the Gulf Friday into Saturday. There is
potential for storm force outflow winds Sunday morning across the
usual gaps and passes including Kamishak Bay, the Barren Islands,
Shelikof Strait, and the Gulf side of the Alaska Peninsula.
Another gale force front quickly arrives over the western Gulf
Sunday night.

&&

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

Very active weather is expected in the long term as the longwave
pattern amplifies and remains progressive. Over the weekend a
shortwave trough is expected to move over the AKPen and into
Southcentral. This will bring widespread precipitation to most
areas across both domains. The potential for rain exists over
southern Bristol Bay, the AKPen, and Kodiak Island on Saturday
due to warm air aloft. Cold air is expected to quickly follow the
warm front as the trough moves east, bringing chances of snow
throughout the mainland and coastal areas on Sunday. The moisture
feed for this system extends well into the tropics, so potential
for heavy snow exists, particularly for Southcentral. This system
will move east into the Yukon and Southeast Alaska on Sunday,
bringing a brief lull in the weather for the mainland as the next
strong low moves into the western Bering.

Models are in relatively good agreement for the strength and
positioning of the low center in the Western Bering on Sunday.
Minor differences exist as to whether multiple low centers will
develop along the large warm front. Regardless, storm force winds
will likely move east across the Aleutian Chain on Sunday, and
return on Monday with brisk, westerly cold air advection on the
backside of the low. The front will reach the Southwest mainland
Sunday night, where snow and strong winds are likely.
Precipitation may fall as rain again over the AKPen before quickly
transitioning to snow on Monday as the cold air catches up. A
triple point low is likely to develop along the front in the lee
of the AKPen. This will help bring another round of widespread
snow to the southern mainland through Tuesday before the system
moves off to the east.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Heavy Freezing Spray Warning 185 and 139. Storm 352. Gale
150 155 160 165 170 172 173 174 175 176 177 178 179 180 413 414
119 120 130 131 132 137 138 139 141 351.

&&

SYNOPSIS AND MODEL DISCUSSION...PJS
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ALH
MARINE/LONG TERM...CJ