Gale Warning 110, NWS Anchorage, AK

261 
FZAK62 PAFC 070002
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
302 PM AKST Thu Feb 6 2020

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.

PKZ499-071345-
302 PM AKST Thu Feb 6 2020
.SYNOPSIS FOR CENTRAL BERING SEA...
A 989 mb low at 55N 164W moves to 58N 152W at 1008 mb and dissipates
Fri night. A 978 mb low near 47N 178E moves to 54N 170W at 963 mb 
Fri night then to 60N 163W at 975 mb for Sat afternoon. A 962 mb low 
at 47N 164E moves to 48N 177E at 994 mb by Sat afternoon.

$$

PKZ411-071345-
Bering Sea Offshore West of 180 and East of the International
Dateline-
302 PM AKST Thu Feb 6 2020

...GALE WARNING THROUGH FRIDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING FRIDAY NIGHT...

.TONIGHT...E wind 15 to 30 kt increasing to 35 kt after midnight.
Seas 9 to 16 ft. Freezing spray. Snow showers.
.FRI...E wind 40 kt. Seas 14 to 22 ft. Freezing spray.
.FRI NIGHT...NE wind 40 kt. Seas 20 to 24 ft. Heavy freezing
spray. Snow.
.SAT...NE wind 20 to 35 kt. Seas 15 to 23 ft.
.SAT NIGHT...NE wind 15 to 30 kt. Seas 10 to 18 ft.
.SUN...E wind 15 to 30 kt. Seas 8 to 13 ft.
.MON...SE wind 30 to 45 kt. Seas 17 to 29 ft.
.TUE...S wind 15 to 30 kt. Seas 15 to 22 ft.

$$

PKZ412-071345-
Bering Sea Offshore 171W to 180 and North of 56N-
302 PM AKST Thu Feb 6 2020

...STORM WARNING FRIDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...NE wind 20 to 30 kt. Seas 10 to 14 ft. Heavy freezing
spray.
.FRI...NE wind 40 kt. Seas 10 to 18 ft. Heavy freezing spray.
.FRI NIGHT...NE wind 35 to 50 kt. Seas 16 to 24 ft. Heavy freezing
spray.
.SAT...N wind 25 to 40 kt. Seas 13 to 21 ft.
.SAT NIGHT...N wind 10 to 20 kt. Seas 8 to 13 ft.
.SUN...NW wind 15 kt. Seas 6 to 10 ft.
.MON THROUGH TUE...SE wind 20 to 35 kt. Seas 10 to 18 ft.

$$

PKZ413-071345-
Bering Sea Offshore 171W to 180 and South of 56N-
302 PM AKST Thu Feb 6 2020

...STORM WARNING FRIDAY NIGHT...

.TONIGHT...E wind 10 to 25 kt increasing to 20 to 30 kt 
after midnight. Seas 8 to 11 ft.
.FRI...NE wind 25 to 40 kt. Seas 10 to 18 ft.
.FRI NIGHT...NE wind 35 to 50 kt. Seas 21 to 26 ft. 
Freezing spray. Snow.
.SAT...NE wind 25 to 40 kt. Seas 17 to 25 ft.
.SAT NIGHT...NE wind 10 to 25 kt. Seas 10 to 18 ft.
.SUN...E wind 10 to 25 kt. Seas 7 to 11 ft.
.MON...SE wind 25 to 40 kt. Seas 12 to 20 ft.
.TUE...SW wind 10 to 25 kt. Seas 9 to 17 ft.

$$

PKZ414-071345-
Bering Sea Offshore East of 171W-
302 PM AKST Thu Feb 6 2020

...STORM WARNING FRIDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...NE wind 15 to 30 kt. Seas 4 to 9 ft. 
Heavy freezing spray.
.FRI...NE wind 15 to 30 kt increasing to 25 to 40 kt 
in the afternoon. Seas 6 to 11 ft. Heavy freezing spray.
.FRI NIGHT...NE wind 35 to 50 kt. Seas 10 to 18 ft. 
Heavy freezing spray. Snow.
.SAT...N wind 30 to 45 kt. Seas 9 to 17 ft.
.SAT NIGHT...NW wind up to 20 kt. Seas 6 to 11 ft.
.SUN...N wind up to 20 kt. Seas 3 to 8 ft.
.MON THROUGH TUE...SE wind 15 to 30 kt. Seas 4 to 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
500 PM AKST Wed Feb 5 2020

.ANALYSIS AND UPPER LEVELS...
There is an upper level trough over southwest Alaska moving
eastward. Ahead of this trough (to the east) there is considerable
moisture and fairly mild conditions. Snow and snow showers are
being reported at most sites across southern Alaska. A surface low
centered near Bethel is ushering in an Arctic front from the
west. There is a short-wave ridge stretching from the Alaska
Peninsula through the Pribilofs. There is an upper low over the
central and western Aleutians that is moving eastward. Associated
with this upper low is a surface low center just north of the
central Aleutians and one to the south of the central Aleutians.
Another surface low is over the western Bering well north of the
western Aleutians, and this low is moving towards the south.

&&

.MODEL DISCUSSION...
The numerical models are in fairly good agreement through Friday
afternoon. There are some differences in how they handle various
surface low centers associated with a "complex" low crossing the
Aleutians and Alaska Peninsula tonight through Thursday afternoon,
but these are less than in previous runs and do not present too
much of a forecast problem. Thus the forecast confidence is a bit
above normal.

&&

.AVIATION...
PANC...Generally MVFR conditions are expected through Thursday
morning, with a chance of occasional IFR visibilities (and
possibly ceilings) in snow. Light winds are expected through this
evening. Southerly winds will kick in tonight, which may be gusty
at times through Thursday morning.

&&

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

Very light snow ongoing across portions of the area will continue
through the first half of the overnight tonight as weak cold
advection from out of the southwest brings colder air and moisture
into the area. Cooling air and moisture coming together usually
results in precipitation as the air cannot hold onto the moisture,
so it falls out as snow. That is what is happening over much of
Southcentral this afternoon. The upper level wave helping cause
the snow passes through late tonight. Behind it, a period of
clearing should result in a lot of sunshine for much of the day
Thursday. The next system moves into Southcentral Thursday night
as a front and its associated low move into the western Gulf. Much
of the focus for precipitation is expected along the coast. Some
very light precipitation may make it inland, but little
precipitation is expected on Friday.

The primary impactful weather expected across Southcentral will
come Friday night into Saturday. As a strong low moves into
Southwest Alaska, its leading front will move into Kodiak Island
late Friday night, then across the rest of Southcentral on
Saturday. Most areas will get a good amount of rain, especially
along the coast. Rain specifically was used as the precipitation
type because this front and low will bring a warmer air mass into
the region along with it. Since the low and front will both be
strong, this will lead to increases in the winds, especially
through Turnagain Arm, higher elevations, and the usual windy
barrier jet areas through Prince William Sound and the north Gulf
coast. As it moves through, the Turnagain Arm wind will likely
move into Anchorage by Saturday afternoon. This will boost
temperatures well into the 40s, and along with gusty winds will
take a bite out of the snowpack. How strong the winds get remains
uncertain, but it's certainly possible that gusts will get to
hurricane force along Turnagain Arm. Gusty winds through the Knik
River Valley moving into the Matanuska Valley will also boost
temperatures to around 40 in those areas as well. Meanwhile the
strong onshore push through Prince William Sound may cause a
period of potentially heavy snow through the mountains around
Thompson Pass as well, though fortunately the period of time where
heavy snow will be possible will be short.

&&

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

A weakening low over the Y-K Delta continues to move inland. South
flow over the Southwest Mainland has given way to southwest flow
behind the low, bringing temperatures down from their peak this
morning. Showers are starting to diminish in coverage, as the
source of lift exits the area and a shortwave ridge builds in from
the west. Expect some patchy fog along the Bristol Bay coast
tonight and Thursday morning with this. That said, models indicate
potential for a deformation band to set up tonight, bringing
another steady round of snow to the Kuskokwim Mountains into the
Alaska Range.

A distinct cooling and drying trend is expected tonight into Friday,
particularly for the Kuskokwim Valley/Delta. North/northeast flow
along an Arctic front has dropped temperatures in Chevak and
Hooper Bay around 20 degrees over the last 24 hours, with sea
level pressure rising 7 mb. Expect temperatures to drop to the
negatives in the Kuskokwim Delta tonight. The coldest windiest
conditions will be along the coast north of Kipnuk, though it
will depend how far south the front propagates tonight. The
Kilbuck/Ahklun/Russian Mountains will provide some blocking for
the middle Kuskokwim Valley and Bristol Bay area, thus those areas
shouldn't have as dramatic of a cool down as the Kuskokwim Delta
and lower Kuskokwim Valley. As for the Kuskokwim Delta, a Wind
Chill Advisory is in effect Thursday evening. A low will form
near the AKPEN late Thursday into Friday, bringing another round
of precipitation to the Bristol Bay area into the Alaska Range.
The challenge will be determining how far north precipitation
reaches, and a few factors are increasing uncertainty right now.
The cold, dry air over the Kuskokwim Delta will provide a good
wedge for wrap-around moisture to overrun; however, the low may
move east too quickly for precipitation to overcome the dry air in
the low levels. Also, there is still model disagreement in the
track of the low. If the low stays too far south and heads toward
the Gulf, the potential for precipitation farther north will
diminish.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

A vertically stacked low centered roughly 150 miles south of Adak,
and several secondary lows north of the chain is shifting
eastward across the North Pacific. Its leading front will continue
to bring a swath of precipitation to the Aleutians from west to
east tonight into Thursday, with widespread showers in the cold
air mass behind the front. Arctic troughing will strengthen
Thursday into Friday. Expect cold air advection showers over much
of the Bering Friday. A series of lows will track south of the
Aleutians during this time frame, enhancing geostrophic flow over
the central Bering. Expect widespread easterly gales and
heightened freezing spray concerns Friday.

&&

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

Gulf of Alaska:

A strong low will be in the eastern Bering Sea with a front
extending across the Gulf of Alaska Friday. This low and front
will likely support gale force winds across the Gulf of Alaska,
Kodiak Island Waters and the North Gulf Coast Saturday. The lows
and gradient weaken Sunday and wind across the Gulf of ALaska,
Kodiak Island and south central Alaska coastal waters will remain
below gale force Sunday and Monday.

Bering Sea/Aleutians:

Beginning Friday night, storm force winds will move over the
waters south of the Aleutians and track eastwards. By Saturday,
the winds north of the AK Pen will strengthen to storm force as
well. This storm is expected to weaken rapidly during the day on
Saturday and by Sunday, winds will weaken to gales or lighter
across the area. Late Sunday, a new storm in the western Aleutians
will bring gale force winds, but these will remain west of Atka
and continue to weaken through Monday.

&&

.LONG TERM FORECAST (Days 3 through 7: Saturday through Wednesday)...

Active weather remains on tap for the southern mainland and
Kodiak Island through the long term Saturday through Wednesday.
Strong low pressure over the eastern bering Sea supports a strong
gradient across SouthCentral Alaska Saturday along with an influx
of warm moist air. This will bring above normal temperatures to
the region along with strong winds, especially across the coastal
mountains, that will support Chinook-like conditions. Continuing
through the weekend there will be a strong southwest flow. An
upper level ridge then pushes into western Alaska and builds over
the mainland through Tuesday to then have a strong upper level
trough push into the mainland Wednesday. At the surface the models
are not in great agreement, thus the confidence in the longer
term forecast is not high and will reflect the expected trends of
the weather for Monday through Wednesday.

In the west, the first concern is the storm moving through the
region on Saturday. There is some warm air associated with this
system, but that looks like it will remain over Bristol Bay and
the Upper Kuskokwim Valley. Meanwhile, northerly winds to the west
will bring plenty of cold air down over the Kuskokwim Delta.
Residents in this area should be on the lookout for traditional
wintry weather with winds and snow reducing visibility along the
coast. By Sunday this system will weaken dramatically as it moves
northeastward and relatively quiet conditions will begin the week.
As we move into Tuesday and Wednesday, the model forecasts begin
to differ greatly. GFS indicates a strengthening low in the
central Aleutians, but other model solutions indicate a weaker low
moving through the Bering. Therefore, confidence is low on timing
and strength of weather systems moving through western Alaska
through the middle of next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY: 160 179 185 411 412 414
         GALE: 155 177 178 185 411
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...JW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MM
MARINE/LONG TERM...LF/SA