Storm Warning 140, NWS Anchorage, AK

029 
FZAK62 PAFC 201227
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
327 AM AKST Sun Nov 20 2022

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-210230-
327 AM AKST Sun Nov 20 2022
.SYNOPSIS FOR CENTRAL BERING SEA...

A 983 mb low near 51N 165W tracks along the Aleutians to 56N 157W
at 985 mb Mon afternoon. Its front will sweep across the region.

$$

PKZ411-210230-
Bering Sea Offshore West of 180 and East of the International
Dateline-
327 AM AKST Sun Nov 20 2022

...GALE WARNING THROUGH TONIGHT...

.TODAY...N wind 30 to 45 kt. Seas 15 to 23 ft.
.TONIGHT...NW wind 25 to 40 kt. Seas 12 to 20 ft. Freezing spray.
.MON...NW wind 15 to 30 kt becoming 20 kt in the afternoon. Seas
8 to 13 ft. Freezing spray.
.MON NIGHT...W wind 10 to 25 kt. Seas 6 to 10 ft.
.TUE...SW wind 25 to 40 kt. Seas 8 to 16 ft.
.WED...SW wind 30 to 40 kt. Seas 14 to 22 ft.
.THU...W wind 10 to 25 kt. Seas 14 to 19 ft.

$$

PKZ412-210230-
Bering Sea Offshore 171W to 180 and North of 56N-
327 AM AKST Sun Nov 20 2022

...GALE WARNING THROUGH MONDAY...

.TODAY...N wind 30 to 45 kt. Seas 11 to 19 ft. Rain.
.TONIGHT...N wind 30 to 45 kt. Seas 13 to 21 ft. Freezing spray.
Rain showers.
.MON...NW wind 25 to 35 kt. Seas 14 to 19 ft. Freezing spray.
.MON NIGHT...NW wind 20 to 35 kt. Seas 10 to 18 ft.
.TUE...W wind 15 to 30 kt. Seas 8 to 13 ft.
.WED...SW wind 25 to 40 kt. Seas 10 to 18 ft.
.THU...SW wind 10 to 20 kt. Seas 13 to 18 ft.

$$

PKZ413-210230-
Bering Sea Offshore 171W to 180 and South of 56N-
327 AM AKST Sun Nov 20 2022

...STORM WARNING TODAY...

.TODAY...N wind 35 to 50 kt. Seas 10 to 18 ft. Rain.
.TONIGHT...N wind 30 to 45 kt. Seas 15 to 23 ft. Rain showers.
.MON...NW wind 25 to 35 kt. Seas 14 to 22 ft.
.MON NIGHT...NW wind 20 to 35 kt. Seas 10 to 18 ft.
.TUE...W wind 15 to 30 kt. Seas 9 to 16 ft.
.WED...SW wind 25 to 40 kt. Seas 11 to 19 ft.
.THU...SW wind 10 to 25 kt. Seas 15 to 18 ft.

$$

PKZ414-210230-
Bering Sea Offshore East of 171W-
327 AM AKST Sun Nov 20 2022

...GALE WARNING MONDAY...

.TODAY...NE wind 20 kt. Seas 6 ft.
.TONIGHT...NE wind 10 to 20 kt becoming N 15 to 30 kt after
midnight. Seas 5 to 10 ft. Rain and snow.
.MON...NW wind 20 to 35 kt. Seas 9 to 17 ft. Rain showers and snow
showers.
.MON NIGHT...NW wind 35 kt. Seas 13 to 19 ft.
.TUE...NW wind 20 to 35 kt. Seas 9 to 17 ft.
.WED THROUGH THU...SW wind 15 to 30 kt. Seas 8 to 16 ft.

$$

279 
FZAK62 PAFC 210011
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
311 PM AKST Sun Nov 20 2022

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-211400-
311 PM AKST Sun Nov 20 2022
.SYNOPSIS FOR CENTRAL BERING SEA...

A 982 mb low at 54N 161W moves into the Gulf Monday night. A front
approaches the western Bering Tuesday afternoon.

$$

PKZ411-211400-
Bering Sea Offshore West of 180 and East of the International
Dateline-
311 PM AKST Sun Nov 20 2022

...GALE WARNING TONIGHT...

.TONIGHT...NW wind 25 to 40 kt diminishing to 20 to 30 kt after
midnight. Seas 11 to 19 ft. Freezing spray.
.MON...NW wind 15 to 30 kt becoming W in the afternoon. Seas 8 to
13 ft. Freezing spray.
.MON NIGHT...W wind 15 to 30 kt. Seas 6 to 11 ft. Rain showers and
snow showers.
.TUE...SW wind 15 to 30 kt. Seas 7 to 12 ft.
.TUE NIGHT...SW wind 20 to 35 kt. Seas 10 to 18 ft.
.WED...SW wind 25 to 40 kt. Seas 15 to 23 ft.
.THU...W wind 10 to 25 kt. Seas 14 to 19 ft.
.FRI...S wind up to 20 kt. Seas 6 to 11 ft.

$$

PKZ412-211400-
Bering Sea Offshore 171W to 180 and North of 56N-
311 PM AKST Sun Nov 20 2022

...GALE WARNING THROUGH MONDAY NIGHT...

.TONIGHT...N wind 30 to 45 kt. Seas 12 to 20 ft. Freezing spray.
.MON...NW wind 25 to 40 kt. Seas 12 to 19 ft. Freezing spray.
.MON NIGHT...NW wind 20 to 35 kt. Seas 9 to 17 ft. Freezing spray.
.TUE...NW wind 10 to 25 kt. Seas 7 to 12 ft.
.TUE NIGHT...SW wind 15 to 30 kt. Seas 6 to 10 ft.
.WED...SW wind 25 to 40 kt. Seas 11 to 19 ft.
.THU...SW wind 10 to 20 kt. Seas 13 to 18 ft.
.FRI...W wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ413-211400-
Bering Sea Offshore 171W to 180 and South of 56N-
311 PM AKST Sun Nov 20 2022

...GALE WARNING THROUGH MONDAY NIGHT...

.TONIGHT...N wind 30 to 45 kt. Seas 15 to 23 ft. Rain.
.MON...NW wind 30 to 40 kt diminishing to 20 to 35 kt in the
afternoon. Seas 13 to 21 ft.
.MON NIGHT...NW wind 20 to 35 kt. Seas 9 to 17 ft. Rain showers.
.TUE...W wind 15 to 30 kt. Seas 10 to 13 ft.
.TUE NIGHT...W wind 15 to 30 kt. Seas 10 to 13 ft.
.WED THROUGH THU...SW wind 20 to 35 kt. Seas 11 to 19 ft.
.FRI...W wind up to 20 kt. Seas 7 to 12 ft.

$$

PKZ414-211400-
Bering Sea Offshore East of 171W-
311 PM AKST Sun Nov 20 2022

...GALE WARNING THROUGH MONDAY NIGHT...

.TONIGHT...N wind 10 to 25 kt increasing to 25 to 40 kt after
midnight. Seas 6 to 11 ft. Rain and snow.
.MON...NW wind 25 to 40 kt. Seas 10 to 18 ft. Rain.
.MON NIGHT...NW wind 30 to 40 kt. Seas 16 to 20 ft. Freezing
spray. Snow.
.TUE...NW wind 20 to 35 kt. Seas 11 to 18 ft.
.TUE NIGHT...NW wind 15 to 30 kt. Seas 9 to 13 ft.
.WED THROUGH THU...SW wind 15 to 30 kt. Seas 9 to 17 ft.
.FRI...W wind 10 to 20 kt. Seas 9 to 14 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
507 AM AKST Sat Nov 19 2022

.ANALYSIS AND UPPER LEVELS...

The big Canadian ridge still is holding tight over interior
Southcentral Alaska. For now, most of Southcentral, especially
interior locations, witness quiet weather due to the influence of
the aforementioned ridge. With temperature inversions still
apparent, Glen Alps currently hovers in the middle 30s while the
Anchorage Bowl sees teens and 20s. Water vapor imagery reveals a
leading shortwave rotating westward through the western Gulf of
Alaska towards Kodiak Island and the Kenai Peninsula. Middleton
Island radar depicts an area of rain over the north-central Gulf
pivoting towards the Kenai Peninsula and Prince William Sound in
association with this advancing wave. Behind this wave and to the
south is a North Pacific low which is lifting northward towards
the southern Gulf.

Out west, the Canadian ridge which has dominated the weather over
Southcentral for the last few days, noses west-southwestward into
Southwestern Alaska and over the eastern Bering Sea. Due to this
ridge trapping in low-level moisture, Kipnuk observes misty
conditions with low visibilities. Bristol Bay locations
experience quiet and mostly clear conditions. Meanwhile, the
Aleutian Chain is under the influence of southerly upper flow
which stems from a North Pacific advancing east-northeastward.
This in turn yields cloudy conditions with low ceilings for the
Chain while the Pribilofs experience mist, and Dutch Harbor sees
rain in association with weak shortwaves coming in from the south.

&&

.MODEL DISCUSSION...

Models remain in good agreement with overall synoptic pattern in
the short term. The main forecast challenge with Southcentral
Alaska will be nailing down precipitation type details,
specifically dealing with the possibility of freezing rain, as
low pressure systems impact the eastern Kenai Peninsula and Prince
William Sound regions through Monday. Meanwhile, the forecast
challenge out west will be nailing down the exact track of a
surface low on the North Pacific side of the Aleutian Chain for
the short term and the associated shortwaves that rotate around
the upper low. Currently, the 00z Canadian is the fast solution
with the low approaching Kodiak Island by Monday afternoon, while
the 00z NAM is is the slowest solution with the low hanging back
by Sand Point at the same time period. The 00z GFS and 00z ECMWF
are kind of in between those track solutions. All-in-all,
confidence is high for active weather to continue during the short
term for both of the domains.

&&

.AVIATION...

PANC...VFR conditions and light winds will prevail through the
TAF package.

&&

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

The change in overall pattern is underway as the low is now in the
Gulf and displacing the warm ridge that was over southern Alaska.
The strong inversion that has been over the area has weakened a
bit but is still a significant part of the weather situation and
even more so now that there is precipitation approaching the
region. For the radiosondes that were launched at 12Z this
morning (2 AM AKST) both Anchorage and Kodiak were above freezing
until around 3700 ft. However, in Kodiak the surface temperature
was 43F while Anchorage started at 22F and rose above freezing
about 500 ft with the warmest level at 2000 ft with at 39F (4C).
For comparison, the Anchorage inversion at the same time
yesterday was up to 44F (6.6C) and finally dropped below freezing
at 7300 ft. This inversion is likely to remain over Anchorage and
the northern Cook Inlet region through Monday so this will make
the precipitation type a challenge. Basically, snow will be hard
to come by at elevations below 2500 to 3500 ft across the Kenai
Peninsula and northern Cook Inlet into the Susitna Valley.
Therefore, areas above freezing will see rain but low-lying areas
where the colder, denser air has collected will see freezing
rain. This will be the situation through at least Sunday.

The inland areas of the eastern Kenai Peninsula are most likely to
see freezing rain today with enough warm air making it in by
tonight to transition precipitation to rain. The Anchorage, MatSu
and western Kenai areas will see a chance for rain and freezing
rain late tonight into Sunday. Precipitation amounts are not
expected to be very much in these areas, but even a little
freezing rain can cause transportation issues.

By Monday, the atmosphere will be slowly cooling off aloft and
most of the areas should see more of the precipitation type go to
snow or rain with the freezing rain chances becoming unlikely by
Monday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today
through Monday night)...

A resident high pressure system over Central Alaska begins to
weaken and its influence is expected to wane into the weekend. As
such, drier, cooler air expected to move in to Southwest Alaska
through tonight. Offshore winds will persist into the first half
of the weekend with a slight cooling trend expected at the
surface. Fog in the Kuskokwim Delta that broke up a few hours ago
is not currently expected to repeat tonight due to slightly
stronger offshore flow, however the potential hasn't been
completely ruled out.

Beginning Saturday morning, light precipitation from a North
Pacific occluded front is expected to commence along the Alaska
Peninsula shakily spreading northward, reaching the Greater
Bristol Bay area by Sunday afternoon. As mentioned, with cooler
temperatures setting in across Southwest leading into the weekend,
precipitation will likely start off as wintry mix for the Bristol
Bay area. This is expected to transition to plain rain as the low
pulls in another batch of warmer air during the day. Monday
evening in the northern Alaska Peninsula, a return to wintry mix
is possible with very light freezing rain and minimal
accumulations possible. Any light precipitation associated with
this system that makes it north of Goodnews Bay is expected to
remain snow through Monday night.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3:
Today through Monday night)...

Currently, a North Pacific low tracking eastward along the south
side of the Aleutian Chain will continue to bring warmer air on
the leading edge along with light precipitation across the Chain.
A shortwave that provided rain to the Pribilofs last night has
moved northwest and will merge with the elongated inverted trough,
stretching from the northwest Bering, south of the Western
Aleutians. This trough will begin to spread to the Central Bering
Sunday, expected to provide precipitation to the Pribilofs
Sunday night. As the low swings eastward it will push a front up
from the Pacific that will provide light precipitation across the
Central Aleutians, spreading eastward as the weekend concludes. On
the western backside of this low, cold air will be drawn down
from Siberia and the northern Bering. This movement is expected to
amplify wind speeds in the western Aleutians, with the core of
northerly winds to shift to the Central Aleutians by Monday
afternoon. Colder air temperatures in combination with strong
winds and low sea surface temperatures mean that freezing spray is
likely in the Northern Bering Sea.

&&

.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)

Looking ahead in the extended forecast, the latest model runs and
ensemble guidance are in fairly decent agreement with the
evolution and progression of the synoptic features. The strong
upper ridge over mainland Alaska breaks down at the start of the
period, but will help deflect the main storm track to the south.
At the start of the period, a series of low pressure systems are
expected to track from the North Pacific into the Gulf of Alaska.
Because of the small to mid-scale interaction of embedded features
moving upstream, models have yet to iron out the intensity and
track of these systems for the coastal areas of Southcentral.

The first deep low moves into the central Gulf Monday through
Tuesday, with heavier precipitation pushing onshore along western
Prince William Sound (PWS) and eastern Kenai Peninsula. This
system may develop a barrier jet along the north gulf coast and
downslope the amount of moisture streaming inland. By Tuesday,
precipitation increases across the inland valleys and throughout
the mountainous areas as the low moves between Cook Inlet and PWS.
A second deep low moves into the eastern Gulf Wednesday through
Thursday, with most of the precipitation along eastern PWS and the
northern Alaska Panhandle.

Out west, a deep trough and strong upper low over eastern Russia
moves southward into the Bering Sea between Monday and Tuesday.
Ahead of the trough/low, a cold front pushes across western Alaska
and brings scattered showers with below normal temperatures. For
the eastern Aleutians and Alaska Peninsula, the main feature to
note is the colder air advection promoting localized gusty winds
out of the bays and passes. Cold, northerly flow over the
relatively warm waters will also help generate widespread showers
over the Pribilof Islands and along the Aleutian Chain.

By midweek, an amplified ridge builds across the western/central
Aleutians before unsettled conditions returns with another upper
trough/low developing between Wednesday and Thursday. The
GFS/EC/CAN are advertising a deep surface low and front with
increasing warm, southerly winds that will impact the western
Bering/Aleutians during the middle part of next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storm Warning: 411
       Gale Warning: 119, 120, 131, 176-178, 185, 351, 412, 413.

FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...DAN
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CL
LONG TERM...MF