Storm Warning 143, NWS Anchorage, AK

798 
FZAK61 PAFC 300052
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
352 PM AKST Sun Nov 29 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.

PKZ399-301445-
352 PM AKST Sun Nov 29 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 984 mb low at 59N 150W weakens to a trough over the north Gulf 
Coast Mon morning. Its front moves inland Mon afternoon. A new 
front enters the western Gulf Mon afternoon and stretches across 
the Gulf through Tue afternoon. A 965 mb North Pacific low moves 
along the front to 55N 155W at 972 mb for Tue afternoon.

$$

PKZ351-301445-
Gulf of Alaska Offshore North of 57N and West of 144W-
352 PM AKST Sun Nov 29 2020

...STORM WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...SW wind 15 to 30 kt. Seas 10 to 17 ft.
.MON...S wind 15 to 30 kt becoming SE 35 to 50 kt in the
afternoon. Seas 9 to 12 ft building to 11 to 19 ft in the afternoon.
Rain.
.MON NIGHT...S wind 35 to 50 kt diminishing to 15 to 25 kt after
midnight. Seas 19 ft.
.TUE...SE wind 15 to 25 kt. Seas 18 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 15 to 19 ft.
.WED THROUGH THU...SE wind 15 to 30 kt. Seas 10 to 18 ft.
.FRI...SW wind 15 to 25 kt. Seas 8 to 12 ft.

$$

PKZ352-301445-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
352 PM AKST Sun Nov 29 2020

...STORM WARNING MONDAY...

.TONIGHT...SW wind 15 to 30 kt. Seas 9 to 17 ft.
.MON...SE wind 35 to 50 kt. Seas 11 to 19 ft. Rain.
.MON NIGHT...S wind 15 to 30 kt. Seas 17 to 21 ft.
.TUE...S wind 20 to 30 kt. Seas 18 to 21 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 16 to 20 ft.
.WED THROUGH FRI...SW wind 15 to 30 kt. Seas 10 to 18 ft.

$$

428 
FZAK61 PAFC 301250
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
350 AM AKST Mon Nov 30 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.

PKZ399-010215-
350 AM AKST Mon Nov 30 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front enters the Western Gulf Mon morning associated with a 964
mb moves across the Gulf into the eastern Gulf by Tue morning. A
front associated with a 980 mb low at 58N 153W Wed morning 
persists across the Gulf.

$$

PKZ351-010215-
Gulf of Alaska Offshore North of 57N and West of 144W-
350 AM AKST Mon Nov 30 2020

...STORM WARNING TODAY...

.TODAY...S wind 15 to 30 kt becoming SE 35 to 50 kt in the
afternoon. Seas 9 to 12 ft building to 11 to 19 ft in the
afternoon. Rain.
.TONIGHT...S wind 30 to 45 kt diminishing to 15 to 25 kt after
midnight. Seas 19 ft.
.TUE...SE wind 15 to 25 kt. Seas 18 ft. Rain.
.TUE NIGHT...S wind 20 to 30 kt. Seas 15 to 19 ft.
.WED...SW wind 15 to 25 kt. Seas 13 to 18 ft.
.THU...W wind 10 to 20 kt. Seas 10 to 15 ft.
.FRI...SW wind up to 15 kt. Seas 6 to 9 ft.

$$

PKZ352-010215-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
350 AM AKST Mon Nov 30 2020

...STORM WARNING TODAY...

.TODAY...SE wind 35 to 50 kt. Seas 11 to 19 ft. Rain.
.TONIGHT...S wind 15 to 30 kt. Seas 17 to 21 ft. Rain showers.
.TUE...S wind 20 to 30 kt. Seas 18 to 21 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 16 to 20 ft.
.WED...SW wind 10 to 25 kt. Seas 12 to 20 ft.
.THU THROUGH FRI...E wind up to 20 kt. Seas 8 to 13 ft.

$$

094 
FZAK61 PAFC 010011
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
311 PM AKST Mon Nov 30 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.

PKZ399-011415-
311 PM AKST Mon Nov 30 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front extends across the Gulf through Wed afternoon. A 969 mb
North Pacific low Tue morning moves along the front to 60N 152W
at 979 mb then inland for Wed afternoon.

$$

PKZ351-011415-
Gulf of Alaska Offshore North of 57N and West of 144W-
311 PM AKST Mon Nov 30 2020

...STORM WARNING TONIGHT...

.TONIGHT...E wind 40 to 50 kt in the evening becoming S wind 25 kt 
after midnight. Seas 17 to 21 ft.
.TUE...S wind 20 to 30 kt. Seas 18 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 16 to 19 ft.
.WED...SW wind 10 to 25 kt. Seas 13 to 17 ft.
.WED NIGHT...W wind up to 20 kt. Seas 12 ft.
.THU THROUGH SAT...NE wind up to 20 kt. Seas 8 to 13 ft.

$$

PKZ352-011415-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
311 PM AKST Mon Nov 30 2020

...GALE WARNING TONIGHT...

.TONIGHT...SE to SW wind 25 to 40 kt. Seas 15 to 22 ft. Rain 
showers.
.TUE...S wind 20 to 30 kt. Seas 19 ft.
.TUE NIGHT...SW wind 15 to 30 kt. Seas 15 to 21 ft.
.WED...W wind 10 to 20 kt. Seas 12 to 18 ft.
.WED NIGHT...W wind 10 to 20 kt. Seas 10 to 15 ft.
.THU THROUGH SAT...NE wind 10 to 25 kt. Seas 9 to 14 ft.

$$

460 
FZAK61 PAFC 011315
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
415 AM AKST Tue Dec 1 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.

PKZ399-020200-
415 AM AKST Tue Dec 1 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front in the central Gulf remains nearly stationary through Tue
night. The associated 969 mb low at 55N 156W moves north and
inland at 980 mb Tue night. Weak low pressure remains in the
northern Gulf through Wed night.

$$

PKZ351-020200-
Gulf of Alaska Offshore North of 57N and West of 144W-
415 AM AKST Tue Dec 1 2020

.TODAY...S wind 20 to 30 kt. Seas 18 ft.
.TONIGHT...S wind 20 to 30 kt. Seas 16 to 19 ft.
.WED...SW wind 10 to 25 kt. Seas 12 to 17 ft.
.WED NIGHT...W wind up to 20 kt. Seas 11 to 15 ft.
.THU...NW wind up to 15 kt. Seas 8 to 13 ft.
.FRI THROUGH SAT...E wind up to 20 kt. Seas 7 to 12 ft.

$$

PKZ352-020200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
415 AM AKST Tue Dec 1 2020

.TODAY...S wind 20 to 30 kt. Seas 19 ft.
.TONIGHT...SW wind 15 to 30 kt. Seas 14 to 20 ft.
.WED...W wind 10 to 20 kt. Seas 12 to 18 ft.
.WED NIGHT...W wind 20 kt. Seas 10 to 16 ft.
.THU...NW wind up to 15 kt. Seas 8 to 13 ft.
.FRI...E wind up to 20 kt. Seas 6 to 9 ft.
.SAT...E wind up to 20 kt. Seas 8 to 16 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
520 PM AKST Sat Nov 28 2020

.ANALYSIS AND UPPER LEVELS...

The upper level pattern continues to present a complex longwave
trough over our forecast area. This trough has shifted east over
the past day and is now centered over Southwest AK and encompasses
almost all of our forecast area, save for a shortwave ridge over
the Western Aleutians. A couple of closed upper low centers exist
within this longwave, with one of the lows centered over the
AKPEN. Several shortwave troughs are also embedded in this flow.
There are two prominent shortwaves in our forecast area. One
weakening trough in the Bering supporting a decaying surface low
over the Aleutians. The other is over the Gulf of Alaska
supporting a surface low moving into the Southcentral Gulf Coast.

On the surface, radar is capturing precipitation associated with
the low along the Gulf of Alaska moving into Southcentral AK.
Surface observations are also showing the trough moving in, with
continued snowfall in areas like Portage and Whittier. Slightly
warmer areas farther south on the coast like Homer are seeing a
mix of snow and rain. The latest low center has pushed ashore near
Yakutat, with the next low right on its heels, currently located
south of Kodiak. In southwest, radar also shows wrap around
moisture in Bristol Bay from this system. A weak decaying low is
currently moving south through the Bering and not producing much
weather.

&&

.MODEL DISCUSSION...

As with the past few days, models are handling synoptic features
well in the short term and depicting the longwave pattern well.
They are continuing to struggle on the mesoscale and with local
effects, especially for Southcentral AK. There has been almost
continuous adjustment to the forecast the past couple of days as
a result. Today is a little better, in part because the pattern
has briefly quieted. However, models still struggle after about
48 hours. In our western domain, models are performing better. So,
we have high confidence in models out west, with lower confidence
in Southcentral.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&

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

A gigantic area of low pressure east of Kodiak Island remains to
be the primary weather producer for Southcentral this afternoon.
A weakening frontal zone over Prince William Sound (PWS) continues
lifting inland and dissipating. Still, more snowfall from this
feature will spread across PWS and Copper River Basin, including
Thompson Pass tonight. A shortwave behind this frontal axis will
arrive across PWS and eastern Kenai Peninsula later tonight while
the upper level low make its way toward the northern Gulf and
inland (east of Cordova) overnight tonight. Once this upper low
moves inland and well east of PWS later tonight, snowy conditions will
taper off over much of the area east of the Anchorage Bowl. This
will last only for a short while before the next upper level
system arrives Sunday morning.

Over Shelikof Strait, a developing upper low is parked there
before moving toward PWS Sunday morning. This will cause another
heavy round of heavy mixing rain and snow to return by late
Sunday afternoon if not sooner over PWS and the Copper River
Basin. Meanwhile, a shortwave north of the upper low will break
away and drift northward past Anchorage Bowl by Sunday night. In
response, more snow will spread over Anchorage, Matanuska Valley
and western Kenai Peninsula on Sunday and Sunday night.

Temperature-wise, most of the area will stay at or above normal
this weekend, though Sunday night into Monday could offer a brief
return to colder, more normal temperatures. This will be brief,
however, because the next low in this parade of storms looks to
bring much warmer conditions and rain chances to much of Southcentral
by early next week.

&&

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

An upper level low continues to spin over the region with its
associated surface low to the east of Kodiak Island. The surface
low will continue moving northward through the Gulf of Alaska
while weakening. However, energy associated with the upper level
low is keeping light snow and low visibilities across the
Kuskokwim Mountains and across northern and central Bristol Bay in
areas such as Koliganek and New Stuyahok. This energy will only
ever so slowly move southward out of the region heading into the
overnight hours. Therefore, light snow was kept in the forecast
with some accumulation until Sunday morning before finally
dissipating. Due to the light snow, only an additional inch of
snow accumulation is anticipated. Radar imagery was showing some
returns possibly making it into the Bethel area this afternoon
through the evening hours. With this in mind, we opted to just
put flurries in the forecast as some moisture may make it into the
area.

This system finally pulls away by late Sunday morning. Skies are
expected to clear the most out over the Yukon-Kuskokwim Delta
with partly cloudy to mostly cloudy skies elsewhere. With the
recent snow and residual moisture in the air, areas of patchy fog
are possible for Monday morning. Other than that, expect a dry but
cold Sunday afternoon through Monday morning before the next
system approaches. Temperatures Sunday afternoon across the
interior areas are expected to be in the upper single digits and
teens with 20s along the coast. Temperatures will become very cold
for Monday morning with single digits below zero across the
interior areas and single numbers and teens along the coastal
areas. The one thing possibly going against it getting this cold
Monday morning is the potential cloud cover that may be around. If
skies clear, the potential is there for temperatures to fall even
further than already forecast. Also, areas of patchy fog will
also play a role in the temperatures for Monday morning.

Lastly, the next storm system moves into the area Monday morning
and continues to affect the area through Tuesday night. This event
should be all snow for areas west of a Lime Village to Koliganek
to New Stuyahok to Dillingham line. Areas east of the
aforementioned line have the potential for a snow changing to rain
situation as warmer air comes in and then back to snow when the
cold air comes back in. These areas may also just mix with rain
briefly especially areas around Iliamna. King Salmon is a tough
forecast for this system as the gradient between warm and cold is
expected to be sharp making any shift in the storm track
detrimental to the type of precipitation that will fall. A further
west track means more rain and warmer for King Salmon with
further east colder and more snow. Of course, the downsloping risk
is there as well with this system and depending on how strong the
downsloping is will factor into the amount of precipitation seen.
Interior Bristol Bay and the Middle Kuskokwim Valley have the
potential to see significant snowfall (greater than 6 inches) from
this event where a band of snow might set up. Where this band
sets up remains in question but where it does could see
significant snowfall and headlines will be possible with the
coming forecast packages.

&&

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

Cold air flowing over the Bering is creating an unstable
atmospheric setup. This is seen on visible satellite imagery in
the form of cumulus clouds. Some of these grow enough to cause
snow showers that may briefly reduce visibility and lower
ceilings for the Pribilofs and the eastern Aleutian Chain (Cold
Bay and Sand Point). This will continue for the duration of this
forecast package, especially for the Pribilofs north and west.

The next weather system is expected to affect the areas mainly
south and west of the Pribilofs with storm force winds especially
in the marine zones south of the Aleutian Chain. The timing on
these storm force winds are expected to be early Sunday morning
through Monday morning. Seas of 20-30 ft are expected south of the
Chain with 16-21 ft seas for the Bering side. The one other thing
to note is the potential for blowing snow Monday afternoon into
early Tuesday for the eastern Aleutians as the cold air is coming
back in and precipitation is still occurring. The better risk for
this is around Cold Bay and False Pass which will have a better
chance of keeping the cold air in place. Sand Point has the
better risk to have rain occurring and having the precipitation
shut off before the winds ramp up Tuesday morning for any blowing
snow to occur.

&&

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

Gulf: A well-developed low moves over the Western Gulf through
Thu. Its model track and development are mixed with the wrapped
low as it weakens. However, widespread southerly high-end small
craft winds and waves with local areas of gale force winds move
over the Gulf through Thu. These winds will diminish to
southwesterly small craft over the Gulf and local southeasterly
small craft winds around the Barren Islands, Kamishak Bay and
lower Cook Inlet.

Bering: A well-developed low moves into the Gulf of Alaska weakens
by Thu. The model track and development of the wrapped low vary
through Thu. Northerly gale force winds and waves over the
Central and Eastern Bering and Alaska Peninsula diminish to small
craft winds over the Eastern Bering and West Coast waters. Cold
high pressure dips into the Bering for Thu, but an upper level
trough brings easterly small craft winds to the West of St Matthew
Island Wed and Thu.

&&

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

A weakening low pushes through Cook Inlet on Wednesday, keeping
the Southcentral coastal areas under showery conditions.
850mb temperatures remain warm enough to keep precipitation as all
rain, followed by a brief period of rain/snow mix on Thursday.
Models differ slightly with this low, where the Canadian/ECMWF
dissipate the low as it makes its way onshore, while the GFS
lingers it over Bristol Bay through Friday. This will have an
impact on a second low that enters the Southern Gulf by Thursday
afternoon where the GFS path is pushed more towards the Southeast
Coast. Both the Canadian and ECMWF solutions track this low north
towards the Southcentral Coast with slight differences between
strength and center location. These differences in model solutions
can impact precipitation type and intensity for the Southcentral
Coast for Friday and will need to be monitored over the next few
days. A third system tracks south of the Aleutians late next week
and will bring gusty winds to the central/eastern Aleutian Chain.
Additionally, persistent upper-level troughing lingers over the
Southwest region through Friday. Flow with this will be
predominantly northerly, thus, below average temperatures can be
expected over the Southwest mainland and the AKPEN/eastern
Aleutians.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Heavy Freezing Spray Warnings 160 180 181.
		 Storm Warning 172 174 175 176 177 178.
	     Gale Warning 150 155 160 165 170 171 173 132.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...BB
SOUTHCENTRAL ALASKA...CB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MV
MARINE/LONG TERM...KM