Gale Warning 460, NWS Anchorage, AK

289 
FZAK61 PAFC 202318
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
318 PM AKDT Sun Sep 20 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-211330-
318 PM AKDT Sun Sep 20 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 1003 mb low at 58N 143W this afternoon will dissipate as a front
moves into the central Gulf Monday afternoon. The front will
then strengthen and remain stationary along the Gulf coast through 
Tue afternoon.

$$

PKZ351-211330-
Gulf of Alaska Offshore North of 57N and West of 144W-
318 PM AKDT Sun Sep 20 2020

...GALE WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...Variable 10 to 15 kt becoming SW after midnight. 
Seas 6 ft.
.MON...SE wind 15 to 35 kt. Seas 6 building to 11 ft by afternoon. 
Rain.
.MON NIGHT...E wind 25 to 40 kt. Seas 12 ft building to 16 ft 
after midnight. Rain.
.TUE...E wind 30 to 45 kt. Seas 14 to 22 ft.
.TUE NIGHT...E wind 25 to 40 kt. Seas 13 to 21 ft.
.WED...E wind 10 to 25 kt. Seas 9 to 17 ft.
.THU THROUGH FRI...S wind up to 15 kt. Seas 6 ft.

$$

PKZ352-211330-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
318 PM AKDT Sun Sep 20 2020

...GALE WARNING MONDAY and MONDAY NIGHT...

.TONIGHT...W wind 10 to 20 kt becoming SE 15 to 30 kt after midnight.
Seas 5 to 8 ft.
.MON...SE wind 20 to 35 kt. Seas 7 ft building to 12 ft by 
afternoon. Rain.
.MON NIGHT...SE wind 15 to 35 kt. Seas 9 to 12 ft.
.TUE...E wind up to 15 kt. Seas 10 to 14 ft.
.TUE NIGHT...NE wind up to 10 kt. Seas 10 to 14 ft.
.WED THROUGH FRI...W wind up to 20 kt. Seas 7 to 12 ft.

$$

036 
FZAK61 PAFC 211135
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
335 AM AKDT Mon Sep 21 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-220145-
335 AM AKDT Mon Sep 21 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 982 mb low at 52N 159W this morning will move to 51N 148W at 979 
mb Tuesday morning. The low then moves to 56N 143W at 976 mb 
Wednesday morning. 

$$

PKZ351-220145-
Gulf of Alaska Offshore North of 57N and West of 144W-
335 AM AKDT Mon Sep 21 2020

...GALE WARNING THROUGH TUESDAY...

.TODAY...SE wind 20 to 35 kt. Seas 6 to 11 ft. Widespread rain
showers.
.TONIGHT...E wind 25 to 40 kt. Seas 10 to 16 ft. Rain.
.TUE...E wind 30 to 45 kt. Seas 14 to 22 ft.
.TUE NIGHT...E wind 25 to 40 kt. Seas 13 to 21 ft.
.WED...E wind 10 to 25 kt. Seas 9 to 17 ft.
.THU THROUGH FRI...S wind up to 20 kt. Seas 5 to 10 ft.

$$

PKZ352-220145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
335 AM AKDT Mon Sep 21 2020

...GALE WARNING TODAY...

.TODAY...SE wind 20 to 35 kt. Seas 7 to 12 ft. Rain.
.TONIGHT...SE wind 15 to 30 kt diminishing to up to 20 kt after
midnight. Seas 9 to 12 ft.
.TUE...E wind up to 20 kt becoming SE in the afternoon. Seas 10 to
14 ft.
.TUE NIGHT...NE wind 10 kt. Seas 10 to 14 ft.
.WED...N wind up to 20 kt. Seas 8 to 13 ft.
.THU THROUGH FRI...SW wind 10 to 25 kt. Seas 5 to 10 ft.

$$

118 
FZAK61 PAFC 212326
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
326 PM AKDT Mon Sep 21 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-221345-
326 PM AKDT Mon Sep 21 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 983mb low at 54N 155W this afternoon will move to 57N 149W at
980 mb Tuesday afternoon. A second low will merge with the initial
low near 58N 146W Wednesday afternoon at 978 mb.

$$

PKZ351-221345-
Gulf of Alaska Offshore North of 57N and West of 144W-
326 PM AKDT Mon Sep 21 2020

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...E wind 25 to 40 kt. Seas 10 to 17 ft. Rain.
.TUE...E wind 25 to 45 kt. Seas 13 to 21 ft.
.TUE NIGHT...E wind 15 to 35 kt. Seas 11 to 18 ft.
.WED...E wind 10 to 25 kt. Seas 10 to 17 ft.
.WED NIGHT...E wind 10 to 25 kt. Seas 9 to 14 ft.
.THU THROUGH SAT...S wind up to 20 kt. Seas 5 to 10 ft.

$$

PKZ352-221345-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
326 PM AKDT Mon Sep 21 2020

.TONIGHT...SE wind 15 to 30 kt diminishing to up to 20 kt 
after midnight. Seas 10 to 14 ft.
.TUE...E wind 10 to 15 kt. Seas 10 to 14 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 9 to 13 ft.
.WED...N wind up to 15 kt. Seas 7 to 12 ft.
.WED NIGHT...W wind up to 20 kt. Seas 7 to 10 ft.
.THU THROUGH SAT...SW wind 10 to 25 kt. Seas 5 to 10 ft.

$$

225 
FZAK61 PAFC 221017
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
217 AM AKDT Tue Sep 22 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-230100-
217 AM AKDT Tue Sep 22 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A front along the Gulf coast will weaken Tuesday night through 
Wednesday. A complex series of lows will track from the eastern Gulf 
to the western Gulf Tue night through Wed.

$$

PKZ351-230100-
Gulf of Alaska Offshore North of 57N and West of 144W-
217 AM AKDT Tue Sep 22 2020

...GALE WARNING TODAY...

.TODAY...E wind 25 to 40 kt. Seas 13 to 21 ft.
.TONIGHT...E wind 10 to 25 kt. Seas 12 to 18 ft.
.WED...NE wind 15 to 30 kt. Seas 10 to 15 ft.
.WED NIGHT...SE wind 10 to 25 kt. Seas 9 to 14 ft.
.THU...SE wind 10 to 20 kt. Seas 5 to 10 ft.
.FRI THROUGH SAT...SE wind 10 to 25 kt. Seas 6 to 11 ft.

$$

PKZ352-230100-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
217 AM AKDT Tue Sep 22 2020

.TODAY...SE wind 10 kt. Seas 9 to 13 ft.
.TONIGHT...NE wind 10 kt. Seas 9 to 13 ft.
.WED...NW wind 10 to 20 kt. Seas 8 to 12 ft.
.WED NIGHT...W wind 10 to 25 kt. Seas 7 to 10 ft.
.THU THROUGH SAT...W wind 15 to 30 kt. Seas 6 to 11 ft.

$$

160 
FZAK61 PAFC 222353
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
353 PM AKDT Tue Sep 22 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-231430-
353 PM AKDT Tue Sep 22 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 980 mb low at 56N 151W will move into the north Pacific 
Wednesday morning. A second low will move to 58N 145W at 979 mb 
Wednesday afternoon. The low will then move to 58N 148W Thursday 
afternoon.

$$

PKZ351-231430-
Gulf of Alaska Offshore North of 57N and West of 144W-
353 PM AKDT Tue Sep 22 2020

.TONIGHT...E wind 10 to 25 kt. Seas 12 to 18 ft.
.WED...E wind 15 to 30 kt, except variable wind up to 20 kt W of 146
W. Seas 10 to 15 ft.
.WED NIGHT...SE wind 10 to 20 kt. Seas 7 to 12 ft.
.THU...SE wind up to 15 kt. Seas 7 ft.
.THU NIGHT...S wind 10 to 20 kt. Seas 5 to 9 ft.
.FRI THROUGH SUN...S wind 10 to 25 kt. Seas 6 to 11 ft.

$$

PKZ352-231430-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
353 PM AKDT Tue Sep 22 2020

.TONIGHT...SE wind 10 to 15 kt becoming NE after midnight. Seas 9 to
13 ft.
.WED...NW wind 10 to 20 kt. Seas 11 ft.
.WED NIGHT...W wind 10 to 25 kt. Seas 10 ft.
.THU...W wind 10 to 25 kt. Seas 7 to 10 ft.
.THU NIGHT...W wind 15 to 25 kt. Seas 7 to 10 ft.
.FRI THROUGH SUN...SW wind 15 to 30 kt. Seas 6 to 11 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
431 PM AKDT Sat Sep 19 2020

.ANALYSIS AND UPPER LEVELS...

A shortwave ridge axis extends from the north Pacific, through
southwest Alaska, up through the center part of the state. This is
in between a trough that extends from eastern Siberia through the
central Aleutians, and an area of low pressure across the
southern Gulf. Area radar imagery shows showers with this low
moving northward through the Gulf Coast, with other showers trying
to move into coastal locations of southwest Alaska as the
aforementioned ridge breaks down.

&&

.MODEL DISCUSSION...

The models are generally in good agreement at the surface and
aloft over the next few days, leading to higher than average
forecast confidence.

&&

.AVIATION...

PANC...VFR conditions along with southerly winds occasionally
gusting into the 20 to 25 knot range will persist through this
evening. MVFR ceilings are possible after 8z due to an increase in
shower activity around the terminal. There is also some indication
in the forecast guidance that IFR ceilings may develop over the
terminal after 14z. Confidence in this is low, however, and is
currently not included in the current TAF package.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Sat
afternoon through Tue afternoon)...

An upper level trough to our west will move in this evening,
bringing increasing chances for rain across Southcentral. The
greatest amount of precipitation will be along the northern Gulf
coast and the eastern Kenai Peninsula. There are some showers
lifting northward this afternoon over Prince William Sound and
across the Susitna Valley, but as this trough moves in, rain is
expected to become more widespread. Sunrise on Sunday morning may
reveal sights of termination dust across the higher elevations of
the Chugach and Talkeetna Mountains, as cooler temperatures aloft
allow for overnight precipitation to fall as snow.

As the trough exits to the north Sunday afternoon, conditions
should generally improve over the Susitna Valley, western Kenai
Peninsula, and Anchorage Bowl, though a stray mountain shower
cannot be ruled out. Additional rainfall is likely for the Prince
William Sound area as well as across the Copper River Basin
through Sunday night.

By Monday, the attention shifts westward, where a large low
developing over the Bering moves toward the southeast and lifts a
front across Kodiak Island early Monday. Abundant moisture and
gusty easterly winds are likely, with gale force winds expected
along the extent of this front across the Gulf waters. While the
low center remains well south of Southcentral over the Gulf, the
associated front will bring gusty winds and rain to the northern
Gulf coast as it lifts northward Tuesday morning. Once again, the
bulk of precipitation is expected to fall across Kodiak Island and
the northern Gulf coast, while interior areas of Southcentral
including the Susitna Valley and northern Copper River Basin
should remain relatively dry through Tuesday.

&&

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

Generally quiet conditions are expected through the weekend. Weak
shortwave troughs are currently producing isolated showers across
portions of the Kuskokwim Delta and Bristol Bay. These will
gradually taper off overnight under a weak upper level ridge.
Combined with weak southerly flow, patchy fog and/or low stratus
is possible near the Kuskokwim Delta coast. A similar pattern is
expected for Sunday with weak shortwaves propagating over
Southwest Alaska bringing isolated showers. A front associated
with a low over the eastern Aleutians will bring gusty easterly
winds to much of the region by Monday. As such, conditions will
remain dry in the lee of the Alaska Range and temperatures will
drop slightly, with lows well into the 30s over interior areas.

&&

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

A broad low will move southeast across the Bering through the
weekend. Its associated front will bring steady rain and gusty
southerly winds across the Aleutians, while strong northwesterly
winds and showers will develop on its backside. Cold air
advection is starting to become more robust as the fall season
approaches. The low will become vertically stacked near Unalaska
on Sunday evening, thereby weakening. A cool, northwesterly flow
will develop is its wake ahead of a developing ridge over the
western Bering. Thus, showers will continue through early next
week.

&&

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

Gulf of Alaska: A broad and strong storm system is expected to
remain nearly stationary and weaken over the southern Gulf through
Thursday. There is high confidence in Gale force winds over the
northern Gulf coast with potential for storm force gusts if a
secondary low is to develop in the lee of Kodiak Island on Tue. By
late Wednesday night the low is expected to weaken, which will
bring winds down to at or below small craft criteria.

Bering Sea/Aleutian Islands: There is high confidence that the
broad low pressure system over the Gulf will bring moderate to
strong northerly winds over the eastern Bering. The winds will be
strongest (gale force) through the terrain gaps from Nikolski to
Sand Point through Thursday morning. By this time winds should
calm down to well below gale criteria as the low to the east
breaks down. Over the western Bering, there is high confidence
that high pressure and calm winds are expected to persist through
Wed night. On Thursday confidence decreases significantly in
regards to the next system, with models showing a 20 mb spread.
If the stronger solutions comes to fruition, gale force winds are
possible moving east across the Aleutian Chain Thursday night into
Friday.

&&

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

A broad and strong low pressure system is expected to be centered
over the Gulf at the start of the forecast period. The main impact
from this system will be for the Gulf coast and Kodiak Island,
where strong winds and rain are expected to persist through
Wednesday afternoon. For Southcentral it should be mostly dry,
with seasonal temperatures and the occasional shower as weak
shortwaves move around the low center. On the backside of the
low, strong winds and increasingly cool, northerly wind are
expected to persist over the eastern Bering and coastal areas of
Southwest through Thursday night. By Friday morning, an arctic
trough is expected to move in from the Bering Strait, which will
cool off the Bering considerably through Saturday.

The main forecast question is in regards to the next system
forecast to move over/near the central Aleutians Thursday night.
Forecast confidence decreases considerably due to a large model
spread in both the location and strength of this system. The GFS
and Canadian models have a storm force low clipping the central
Aleutians on Friday as it rapidly moves east into the Gulf by
Saturday morning. The primary difference between these solutions
and the EC, which has a considerably weaker system, is whether or
not jet remains zonal or becomes slightly meridional. If the jet
is to become meridional, then the storm will have a better chance
of tapping into the strong temperature gradient N/S of the
Aleutian Chain to produce a stronger storm. Regardless, model
agreement and forecast confidence increases once again Saturday, with
a strong system moving into the Gulf.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale Warning 160 172-175 177 179 411-414.
Storm Warning 176 178.
FIRE WEATHER...NONE.

&&

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