Gale Warning 497, NWS Anchorage, AK

895 
FZAK52 PAFC 231138
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
338 AM AKDT Wed Sep 23 2020

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.

PKZ199-240030-
338 AM AKDT Wed Sep 23 2020
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A low will persist over the Gulf while high pressure moves over 
the western to central Bering Sea through Wed. A Pacific low will 
track to 200 nm S of Adak Wed morning at 1003 mb. This low will 
weaken and push east. A new 1007 mb low will be 130 nm southeast of 
Attu Island Thursday morning.

$$

PKZ150-240030-
South of the AK Peninsula Sitkinak to Castle Cape-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NW wind 30 kt. Seas 11 ft.
.TONIGHT...NW wind 30 kt. Seas 9 ft.
.THU...NW wind 25 kt. Seas 8 ft.
.THU NIGHT...NW wind 25 kt. Seas 7 ft.
.FRI THROUGH SUN...SW wind 20 kt. Seas 7 ft.

$$

PKZ155-240030-
South of the AK Peninsula Castle Cape to Cape Sarichef-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NW wind 30 kt. Seas 11 ft.
.TONIGHT...NW wind 30 kt. Seas 11 ft.
.THU...NW wind 25 kt. Seas 8 ft.
.THU NIGHT...NW wind 25 kt. Seas 8 ft.
.FRI THROUGH SUN...W wind 20 kt. Seas 6 ft.

$$

PKZ160-240030-
Bristol Bay-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...N wind 25 kt. Seas 7 ft.
.TONIGHT...N wind 25 kt. Seas 7 ft.
.THU...NW wind 20 kt. Seas 5 ft.
.THU NIGHT...N wind 20 kt. Seas 5 ft.
.FRI...NW wind 15 kt. Seas 3 ft.
.SAT...E wind 10 kt. Seas 5 ft.
.SUN...NE wind 10 kt. Seas 4 ft.

$$

PKZ165-240030-
Port Heiden to Cape Sarichef-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...NW wind 30 kt. Seas 10 ft.
.TONIGHT...NW wind 25 kt. Seas 9 ft.
.THU...NW wind 20 kt. Seas 7 ft.
.THU NIGHT...NW wind 20 kt. Seas 6 ft.
.FRI...NW wind 20 kt. Seas 5 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 8 ft.

$$

PKZ170-240030-
Cape Sarichef to Nikolski Bering Side-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY TODAY...

.TODAY...NW wind 25 kt. Seas 9 ft.
.TONIGHT...NW wind 20 kt. Seas 7 ft.
.THU...NW wind 20 kt. Seas 7 ft.
.THU NIGHT...NW wind 15 kt. Seas 5 ft.
.FRI...NW wind 15 kt. Seas 4 ft.
.SAT THROUGH SUN...NW wind 25 kt. Seas 9 ft.

$$

PKZ171-240030-
Unalaska Bay-
338 AM AKDT Wed Sep 23 2020

.TODAY...NW wind 20 kt. Seas 7 ft.
.TONIGHT...NW wind 20 kt. Seas 7 ft.
.THU...NW wind 20 kt. Seas 6 ft.
.THU NIGHT...W wind 15 kt. Seas 3 ft.
.FRI THROUGH SUN...NW wind 15 kt. Seas 4 ft.

$$

PKZ172-240030-
Cape Sarichef to Nikolski Pacific Side-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NW wind 25 kt. Seas 7 ft.
.TONIGHT...NW wind 25 kt. Seas 7 ft.
.THU...NW wind 25 kt. Seas 7 ft.
.THU NIGHT...NW wind 15 kt. Seas 4 ft.
.FRI THROUGH SUN...NW wind 20 kt. Seas 6 ft.

$$

PKZ173-240030-
Nikolski to Seguam Island Bering Side-
338 AM AKDT Wed Sep 23 2020

.TODAY...N wind 15 kt. Seas 7 ft.
.TONIGHT...NW wind 15 kt. Seas 6 ft.
.THU...NW wind 15 kt. Seas 5 ft.
.THU NIGHT...NW wind 15 kt. Seas 4 ft.
.FRI...NW wind 15 kt. Seas 4 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 10 ft.

$$

PKZ174-240030-
Nikolski to Seguam Island Pacific Side-
338 AM AKDT Wed Sep 23 2020

.TODAY...N wind 15 kt. Seas 6 ft.
.TONIGHT...NW wind 15 kt. Seas 4 ft.
.THU...NW wind 15 kt. Seas 4 ft.
.THU NIGHT...W wind 15 kt. Seas 4 ft.
.FRI...NW wind 15 kt. Seas 4 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 10 ft.

$$

PKZ175-240030-
Seguam Island to Adak Bering Side-
338 AM AKDT Wed Sep 23 2020

.TODAY...N wind 15 kt. Seas 6 ft.
.TONIGHT...N wind 15 kt. Seas 5 ft.
.THU...Variable wind 10 kt. Seas 4 ft.
.THU NIGHT...NW wind 15 kt. Seas 3 ft.
.FRI...W wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...NW wind 25 kt. Seas 11 ft.

$$

PKZ176-240030-
Seguam Island to Adak Pacific Side-
338 AM AKDT Wed Sep 23 2020

.TODAY...NE wind 15 kt. Seas 4 ft.
.TONIGHT...N wind 15 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 4 ft.
.THU NIGHT...Variable wind 10 kt. Seas 4 ft.
.FRI...NW wind 15 kt. Seas 5 ft.
.SAT THROUGH SUN...NW wind 25 kt. Seas 9 ft.

$$

PKZ177-240030-
Adak to Kiska-
338 AM AKDT Wed Sep 23 2020

.TODAY...NE wind 15 kt. Seas 7 ft.
.TONIGHT...SE wind 15 kt. Seas 5 ft. Rain showers.
.THU...SE wind 15 kt. Seas 5 ft.
.THU NIGHT...N wind 15 kt. Seas 4 ft.
.FRI...W wind 20 kt. Seas 6 ft.
.SAT THROUGH SUN...W wind 25 kt. Seas 10 ft.

$$

PKZ178-240030-
Kiska to Attu-
338 AM AKDT Wed Sep 23 2020

.TODAY...SE wind 20 kt. Seas 7 ft.
.TONIGHT...SE wind 20 kt. Seas 7 ft. Rain showers.
.THU...N wind 20 kt. Seas 6 ft.
.THU NIGHT...NW wind 20 kt. Seas 5 ft.
.FRI THROUGH SAT...NW wind 30 kt. Seas 12 ft.
.SUN...W wind 25 kt. Seas 7 ft.

$$

PKZ179-240030-
Pribilof Islands Near Shore Waters-
338 AM AKDT Wed Sep 23 2020

.TODAY...N wind 20 kt. Seas 6 ft.
.TONIGHT...NW wind 20 kt. Seas 6 ft.
.THU...N wind 15 kt. Seas 5 ft.
.THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...N wind 20 kt. Seas 5 ft.
.SAT THROUGH SUN...NW wind 25 kt. Seas 6 ft.

$$

PKZ180-240030-
Kuskokwim Delta and Etolin Strait-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...N wind 30 kt. Seas 8 ft.
.TONIGHT...N wind 25 kt. Seas 7 ft.
.THU...N wind 25 kt. Seas 6 ft.
.THU NIGHT...N wind 25 kt. Seas 6 ft.
.FRI THROUGH SAT...N wind 25 kt. Seas 6 ft.
.SUN...N wind 20 kt. Seas 5 ft.

$$

PKZ181-240030-
North and West of Nunivak Island-
338 AM AKDT Wed Sep 23 2020

...SMALL CRAFT ADVISORY TODAY...

.TODAY...N wind 25 kt. Seas 6 ft.
.TONIGHT...N wind 20 kt. Seas 6 ft.
.THU...N wind 20 kt. Seas 5 ft.
.THU NIGHT...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...N wind 25 kt. Seas 8 ft.
.SUN...N wind 20 kt. Seas 6 ft.

$$

PKZ185-240030-
Saint Matthew Island Waters-
338 AM AKDT Wed Sep 23 2020

.TODAY...NW wind 20 kt. Seas 5 ft.
.TONIGHT...NW wind 15 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 3 ft.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI...NE wind 30 kt. Seas 9 ft.
.SAT...NW wind 30 kt. Seas 9 ft.
.SUN...NW wind 20 kt. Seas 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
418 AM AKDT Tue Sep 22 2020

.ANALYSIS AND UPPER LEVELS...
A very large low circulation is embedded within a high amplitude
trough centered from the Gulf of Alaska down into the northeast
Pacific. While the primary low center tracks south of the Gulf,
its frontal system extends northward from the low center to the
Alaska Peninsula then eastward across Kodiak Island and the
central Gulf before heading back southward into the Pacific.
Satellite imagery shows a series of waves (both aloft and at the
surface) tracking northward across the east Pacific then curving
back westward across the Gulf to Kodiak Island. These waves are
helping to drive the front northward across the Gulf. As a result,
winds are rapidly strengthening over the northern to western
Gulf, with widespread gales being observed. Moderate to heavy rain
is also overspreading Prince William Sound and the eastern Kenai
Peninsula. Some areas of light rain are spilling over the coastal
mountains, but the bulk of interior Southcentral is dry.

Out west, a short-wave trough is dropping southward across the
central Bering Sea, with colder air advecting southward and into
the back side of the Gulf/Pacific low. This is producing showers
and gusty winds across the eastern Bering Sea, eastern Aleutians,
and Alaska Peninsula. High pressure is leading to benign weather
fro the remainder of the Bering Sea and Aleutian chain.

&&

.MODEL DISCUSSION...
Models are generally in good agreement with the large scale
pattern and associated weather over the next few days. The one
glaring exception is with cyclogenesis over the Gulf Tuesday
night/Wednesday. All solutions show a stronger upper wave coming
up from the east Pacific and initiating cyclogenesis. However,
low track and depth are all over the map. While this will affect
the wind forecast across the Gulf waters, the end result for the
precipitation forecast will remain the same, with another round
of rain likely along coastal areas.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist. There may be
some periods of light rain, as precipitation spills over top of
the Kenai/Chugach Mountains. This could cause the ceiling to
briefly drop to low end VFR (less than 5000 ft.).

&&

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

The big weather issue in Southcentral is the weather front
approaching the north Gulf coast and wrapping around into Kodiak
Island. The low associated with this front is a complex one that
encompasses a large portion of the Gulf of Alaska. This is
significant as not only are there multiple low centers, but
a number of waves can be seen along the front on satellite
imagery from the eastern Gulf and farther along it to the south.
These waves along the front can cause enhancement of winds and
rain near them and are notoriously difficult for the models to
capture. Therefore, the rain along the coast is a sure thing, but
as the front moves inland it will be a different story.
Downsloping along the lee side of the mountain ranges should keep
the rain out of most of the inland areas, but the downsloping
will likely give way at times to these waves as they move along
the front. Kept a lot of scattered showers over the next two days
for the inland areas, but there may be periods of numerous
showers due to this.

For the marine areas, Storm force winds are still expected today
along the north Gulf cast with this front. Wednesday's forecast is
a little trickier as there will be another low center within the
overall low complex that rotates out of the eastern Gulf into the
northern Gulf. This low should bring some Gale force winds to the
north Gulf coast Wednesday, but the chance for this low to not be
as strong as currently expected is higher than normal so there is
increased uncertainty to those Gales in the marine areas for
tomorrow.

&&

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

A large area of low pressure over the Gulf will allow gusty north
to northeasterly winds to continue across Southwest Alaska and the
Alaska Peninsula through Wednesday. An upper level shortwave
moving from north to south over the Kuskokwim Delta coast may
generate a few showers overnight Tuesday into Wednesday. Otherwise
cool, dry conditions are expected across much of the area through
the end of the week.

&&

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

Northerly winds are expected to persist over the eastern Bering
through the end of the week. Farther west, a ridge of high
pressure gradually attempts to build eastward. By Wednesday night,
an upper level low moves over the western Aleutians. This fast-
moving low will produce gusty winds and rain as it tracks eastward
Thursday before moving south and exiting the area by Thursday
night.

&&

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

Gulf of Alaska: There is moderate confidence that the broad low
pressure system in the western Gulf will break down through Friday
afternoon. The GFS deterministic model has the low remaining in
the Gulf longer than other models but winds and waves should
remain at or below small craft criteria through Friday. On
Saturday there is moderate to high confidence that a Gale force
low will move into the Gulf from the North Pacific. Model spread
of the low center pressure ranges from 975 mb to 986 mb. There is
low confidence in the location of maximum winds at this time due
to high model spread on the east/west location of the low center.

Bering Sea/Aleutian Chain: There is high confidence that winds
and waves will be mostly calm through the region on Thursday. On
Friday morning a Polar trough will bring moderate (<34 kts)
northerly winds through the Bering Strait and into the Bering Sea
by Friday evening. On Saturday a weak northerly shortwave and
surface low may create winds up to gale force over the western
Bering. Confidence in winds reaching gale force on Saturday is
moderate.

&&

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

Synoptically, a broad longwave trough is expected to persist over
the region with the jet centered between the 40th and 50th
parallel. This should continue the fall pattern of rainy weather
for most of the region, but primarily the Bering Sea, AKPEN and
Gulf coast. Late Friday and Saturday will likely be the wettest
for the Alaska Mainland as a moderately strong storm moves into
the Gulf. The broad nature of this system, extending from Bristol
Bay to Southeast Alaska will allow for upper level shortwaves to
bring moisture and rain into the Alaska interior. Model guidance
has come to better agreement in regards to this low, with the low
center moving into the Prince William Sound Sunday morning. By
Monday, model guidance begins to considerably differ once again,
with the GFS bringing the storm back into the Gulf and the EC
pushing it into Bristol Bay.

Northerly flow on the backside of the aforementioned low is
expected to bring a polar airmass over the Bering on Friday. A
series of shortwaves may help provide lift needed for showers
over the western Bering and Aleutian Chain through the forecast
period. Simultaneous ridging over the Kamchatka Peninsula will
help to bring warmer air in from the Western Pacific, thus
setting the stage for the next baroclinic storm in the Western
Bering. Models are in excellent agreement that a Kamchatka low
will form Monday morning with the storms front reaching the
Western Aleutians on Monday afternoon.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 130 137-140 155 172.
		 Storm 119 120 131
FIRE WEATHER...NONE.

&&

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