Gale Warning 765, NWS Anchorage, AK

584 
FZAK51 PAFC 081556 CCA
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
328 AM AKST Tue Dec 8 2020

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-090130-
328 AM AKST Tue Dec 8 2020
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

Low pressure persists over the Northern Gulf through Tuesday
night. A front enters the Western Gulf Tuesday night reaching the
Central Gulf Wednesday morning.

$$

PKZ119-090130-
Cape Suckling to Cape Cleare-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...S wind 25 kt. Seas 15 ft.
.TONIGHT...SW wind 20 kt. Seas 11 ft.
.WED...S wind 20 kt. Seas 11 ft.
.WED NIGHT...S wind 15 kt. Seas 9 ft.
.THU...W wind 20 kt. Seas 8 ft.
.FRI THROUGH SAT...E wind 25 kt. Seas 9 ft.

$$

PKZ120-090130-
Cape Cleare to Gore Point-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...SW wind 25 kt. Seas 15 ft.
.TONIGHT...S wind 25 kt. Seas 11 ft.
.WED...S wind 25 kt. Seas 11 ft.  and snow showers.
.WED NIGHT...W wind 25 kt. Seas 9 ft.
.THU...NW wind 25 kt. Seas 9 ft.
.FRI THROUGH SAT...E wind 30 kt. Seas 11 ft.

$$

PKZ121-090130-
Resurrection Bay-
328 AM AKST Tue Dec 8 2020

.TODAY...S wind 15 kt with gusts to 25 kt. Seas 3 ft. Higher seas S 
of Caines Head. Snow and rain.
.TONIGHT...S wind 10 kt. Seas 2 ft. Higher seas S of Caines Head. Widespread
snow showers.
.WED...Variable wind less than 10 kt. Seas 2 ft. Higher seas S of 
Caines Head. Widespread snow and rain showers.
.WED NIGHT...N wind 10 kt. Seas 2 ft.
.THU...N wind 15 kt. Seas 3 ft.
.FRI...N wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ125-090130-
Prince William Sound-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TODAY...

.TODAY...S wind 25 kt diminishing to 15 kt this afternoon. Seas 6 ft
subsiding to 3 ft. 
.TONIGHT...SE wind 10 kt. Seas 2 ft.
.WED...SE wind 15 kt. Seas 3 ft. Rain showers and widespread snow
showers.
.WED NIGHT...SE wind 15 kt. Seas 3 ft.
.THU...N wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...N wind 15 kt. Seas 2 ft.

$$

PKZ126-090130-
Port Valdez-
328 AM AKST Tue Dec 8 2020

.TODAY...Variable wind less than 10 kt. Seas 2 ft. Widespread snow
showers and rain.
.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Widespread
snow showers.
.WED...Variable wind less than 10 kt becoming NE 10 kt in the
afternoon. Seas 2 ft. Widespread snow showers.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU THROUGH FRI...NE wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-090130-
Valdez Narrows-
328 AM AKST Tue Dec 8 2020

.TODAY...NE wind 15 kt in the morning becoming variable less than
10 kt. Seas 3 ft. Widespread snow showers and rain.
.TONIGHT...NE wind 10 kt. Seas 2 ft. Widespread snow showers.
.WED...NE wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Widespread snow showers.
.WED NIGHT...N wind 15 kt. Seas 3 ft.
.THU THROUGH FRI...NE wind 25 kt. Seas 3 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ128-090130-
Valdez Arm-
328 AM AKST Tue Dec 8 2020

.TODAY...Variable wind 15 kt. Seas 3 ft. Rain and snow.
.TONIGHT...NE wind 10 kt. Seas 2 ft. Widespread snow and rain
showers.
.WED...NE wind 10 kt. Seas 2 ft. Widespread rain and snow showers.
.WED NIGHT...NE wind 10 kt. Seas 2 ft.
.THU THROUGH FRI...NE wind 15 kt. Seas 3 ft.
.SAT...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-090130-
Passage Canal-
328 AM AKST Tue Dec 8 2020

.TODAY...E wind 15 kt. Seas 2 ft. Rain and snow.
.TONIGHT...E wind 10 kt. Seas 2 ft. Snow showers.
.WED...E wind 15 kt. Seas 2 ft. Widespread snow and rain showers.
.WED NIGHT...E wind 15 kt. Seas 2 ft.
.THU...W wind 10 kt. Seas 2 ft.
.FRI...E wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ130-090130-
West of Barren Islands including Kamishak Bay-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TONIGHT AND WEDNESDAY...

.TODAY...SW wind 20 kt. Seas 7 ft.
.TONIGHT...S wind 25 kt. Seas 8 ft. Freezing spray.
.WED...W wind 15 kt increasing to 25 kt in the afternoon. Seas 5
ft building to 9 ft in the afternoon.
.WED NIGHT...W wind 35 kt. Seas 13 ft.
.THU...NW wind 30 kt. Seas 12 ft.
.FRI THROUGH SAT...NE wind 35 kt. Seas 10 ft.

$$

PKZ131-090130-
Barren Islands East-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...SW wind 25 kt. Seas 13 ft.
.TONIGHT...S wind 30 kt. Seas 12 ft.
.WED...SW wind 25 kt. Seas 11 ft.
.WED NIGHT...W wind 30 kt. Seas 13 ft.
.THU...NW wind 30 kt. Seas 9 ft.
.FRI THROUGH SAT...E wind 35 kt. Seas 14 ft.

$$

PKZ132-090130-
Marmot Island to Sitkinak-
328 AM AKST Tue Dec 8 2020

...GALE WARNING THROUGH TONIGHT...

.TODAY...SW wind 35 kt. Seas 15 ft.
.TONIGHT...SW wind 35 kt. Seas 15 ft.
.WED...W wind 25 kt. Seas 11 ft.
.WED NIGHT...W wind 25 kt. Seas 9 ft.
.THU...S wind 20 kt. Seas 6 ft.
.FRI...E wind 40 kt. Seas 18 ft.
.SAT...S wind 35 kt. Seas 17 ft.

$$

PKZ136-090130-
Chiniak Bay-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SW wind 15 kt becoming S 25 kt in the afternoon. Seas 2
ft building to 4 ft in the afternoon.
.TONIGHT...S wind 30 kt. Seas 5 ft.
.WED...SW wind 15 kt. Seas 2 ft.
.WED NIGHT...W wind 15 kt. Seas 2 ft.
.THU...S wind 10 kt. Seas 3 ft.
.FRI THROUGH SAT...SE wind 35 kt. Seas 12 ft.

$$

PKZ137-090130-
Marmot Bay-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SW wind 15 kt becoming S 25 kt in the afternoon. Seas 4 ft.
.TONIGHT...S wind 25 kt. Seas 6 ft.
.WED...SW wind 15 kt. Seas 3 ft.
.WED NIGHT...W wind 15 kt. Seas 3 ft.
.THU...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...E wind 35 kt. Seas 16 ft.

$$

PKZ138-090130-
Shelikof Strait-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...SW wind 25 kt. Seas building to 9 ft in the afternoon. 
.TONIGHT...SW wind 25 kt. Seas 8 ft. Freezing spray.
.WED...W wind 25 kt. Seas 7 ft. Freezing spray.
.WED NIGHT...NW wind 30 kt. Seas 7 ft.
.THU...NE wind 25 kt. Seas 5 ft.
.FRI THROUGH SAT...E wind 40 kt. Seas 11 ft.

$$

PKZ139-090130-
Cook Inlet Kalgin Island to Point Bede-
328 AM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SW wind 25 kt. Seas 7 ft.
.TONIGHT...S wind 25 kt. Seas 8 ft. Freezing spray.
.WED...S wind 20 kt. Seas 6 ft. Snow showers.
.WED NIGHT...W wind 25 kt. Seas 6 ft.
.THU...N wind 20 kt. Seas 5 ft.
.FRI THROUGH SAT...NE wind 30 kt. Seas 7 ft.

$$

PKZ140-090130-
Cook Inlet North of Kalgin Island-
328 AM AKST Tue Dec 8 2020

.TODAY...S wind 20 kt. Seas 6 ft.
.TONIGHT...SE wind 15 kt. Seas 4 ft.
.WED...E wind 15 kt. Seas 4 ft. Snow showers.
.WED NIGHT...NW wind 10 kt. Seas 3 ft.
.THU THROUGH SAT...NE wind 15 kt. Seas 3 ft.

$$

PKZ141-090130-
Kachemak Bay-
328 AM AKST Tue Dec 8 2020

.TODAY...SW wind 15 kt. Gusts to 25 kt through this morning. Seas 6
ft subsiding to 3 ft.
.TONIGHT...S wind 20 kt. Seas 3 ft.
.WED...S wind 15 kt. Seas 2 ft building to 4 ft in the afternoon.
Snow showers.
.WED NIGHT...SW wind 20 kt. Seas 6 ft.
.THU...N wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 3 ft.

$$

728 
FZAK51 PAFC 090030
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
330 PM AKST Tue Dec 8 2020

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-091300-
330 PM AKST Tue Dec 8 2020
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A front moves over the North Gulf Coast for Wed afternoon. A 1001
mb Alaska Peninsula low Wed morning moves to 15 nm northwest of
Kenai at 1016 mb then inland Thu afternoon.

$$

PKZ119-091300-
Cape Suckling to Cape Cleare-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 11 ft.
.WED...S wind 20 kt. Seas 10 ft.
.WED NIGHT...SE wind 20 kt. Seas 8 ft.
.THU...W wind 20 kt. Seas 10 ft.
.THU NIGHT...Variable wind 10 kt. Seas 10 ft.
.FRI THROUGH SAT...E wind 25 kt. Seas 9 ft.
.SUN...Variable wind 10 kt. Seas 10 ft.

$$

PKZ120-091300-
Cape Cleare to Gore Point-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 11 ft.
.WED...S wind 20 kt. Seas 10 ft.
.WED NIGHT...W wind 15 kt increasing to 25 kt after midnight. Seas
9 ft.
.THU...W wind 25 kt. Seas 8 ft.
.THU NIGHT...Variable wind 10 kt. Seas 7 ft.
.FRI THROUGH SAT...E wind 30 kt. Seas 11 ft.
.SUN...SE wind 15 kt. Seas 11 ft.

$$

PKZ121-091300-
Resurrection Bay-
330 PM AKST Tue Dec 8 2020

.TONIGHT...S wind 10 kt in the evening becoming variable less than
10 kt. Seas 2 ft. Widespread snow showers.
.WED...Variable wind less than 10 kt. Seas 2 ft. Widespread snow
showers.
.WED NIGHT...Variable wind less than 10 kt becoming N 10 kt after
midnight. Seas 2 ft.
.THU AND THU NIGHT...N wind 20 kt. Seas 4 ft.
.FRI...N wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ125-091300-
Prince William Sound-
330 PM AKST Tue Dec 8 2020

.TONIGHT...S wind 10 kt. Seas 2 ft.
.WED...SE wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Snow showers.
.WED NIGHT...SE wind 20 kt. Seas 4 ft.
.THU AND THU NIGHT...N wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...N wind 15 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ126-091300-
Port Valdez-
330 PM AKST Tue Dec 8 2020

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Snow showers
and rain showers.
.WED...Variable wind less than 10 kt becoming NE 10 kt in the
afternoon. Seas 2 ft. Snow showers.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU...Variable wind less than 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI...NE wind 10 kt. Seas 2 ft.
.SAT THROUGH SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-091300-
Valdez Narrows-
330 PM AKST Tue Dec 8 2020

.TONIGHT...NE wind 10 kt. Seas 2 ft. Snow showers and rain
showers.
.WED...NE wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Widespread snow showers.
.WED NIGHT...N wind 15 kt. Seas 3 ft. Widespread snow showers.
.THU...N wind 15 kt. Seas 3 ft.
.THU NIGHT...N wind 20 kt. Seas 3 ft.
.FRI...NE wind 25 kt. Seas 3 ft.
.SAT THROUGH SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ128-091300-
Valdez Arm-
330 PM AKST Tue Dec 8 2020

.TONIGHT...NE wind 10 kt. Seas 2 ft. Snow showers.
.WED...NE wind 10 kt. Seas 2 ft. Widespread snow and rain showers.
.WED NIGHT...NE wind 10 kt. Seas 2 ft. Snow and widespread rain
showers.
.THU...NE wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI...NE wind 20 kt. Seas 4 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ129-091300-
Passage Canal-
330 PM AKST Tue Dec 8 2020

.TONIGHT...E wind 10 kt. Seas 2 ft. Snow showers.
.WED...E wind 15 kt. Seas 2 ft. Widespread snow showers.
.WED NIGHT...E wind 15 kt becoming variable 10 kt after midnight. 
Seas 2 ft. Widespread snow showers.
.THU AND THU NIGHT...W wind 15 kt. Seas 2 ft.
.FRI THROUGH SAT...Variable wind less than 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt.

$$

PKZ130-091300-
West of Barren Islands including Kamishak Bay-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING WEDNESDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 9 ft.
.WED...SW wind 15 kt becoming W 25 kt in the afternoon. Seas 6 ft.
.WED NIGHT...W wind 30 kt with gusts to 40 kt. Seas 9 ft. Heavy 
freezing spray near the coast of Kamishak Bay. 
.THU...NW wind 30 kt. Seas 8 ft.
.THU NIGHT...NE wind 25 kt. Seas 5 ft.
.FRI THROUGH SAT...NE wind 35 kt. Seas 11 ft.
.SUN...NE wind 25 kt. Seas 5 ft.

$$

PKZ131-091300-
Barren Islands East-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt. Seas 12 ft.
.WED...SW wind 25 kt becoming W 15 kt in the afternoon. Seas 10 ft.
.WED NIGHT...NW wind 25 kt. Seas 9 ft. Freezing spray.
.THU...W wind 25 kt. Seas 9 ft.
.THU NIGHT...W wind 15 kt. Seas 6 ft.
.FRI THROUGH SAT...E wind 35 kt. Seas 14 ft.
.SUN...S wind 20 kt. Seas 12 ft.

$$

PKZ132-091300-
Marmot Island to Sitkinak-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 13 ft.
.WED...W wind 20 kt. Seas 11 ft.
.WED NIGHT...W wind 20 kt. Seas 8 ft.
.THU...W wind 15 kt. Seas 6 ft.
.THU NIGHT...SE wind 25 kt. Seas 7 ft.
.FRI...E wind 40 kt. Seas 20 ft.
.SAT...S wind 35 kt. Seas 17 ft.
.SUN...SW wind 15 kt. Seas 12 ft.

$$

PKZ136-091300-
Chiniak Bay-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 4 ft.
.WED...SW wind 15 kt. Seas 2 ft.
.WED NIGHT...W wind 15 kt. Seas 2 ft. Freezing spray.
.THU...W wind 10 kt. Seas 2 ft.
.THU NIGHT...SE wind 10 kt. Seas 3 ft.
.FRI...E wind 35 kt. Seas 12 ft.
.SAT...SE wind 35 kt. Seas 12 ft.
.SUN...Variable wind less than 10 kt. Seas 3 ft.

$$

PKZ137-091300-
Marmot Bay-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 4 ft.
.WED...SW wind 15 kt. Seas 3 ft.
.WED NIGHT...W wind 15 kt. Seas 3 ft. Freezing spray.
.THU...W wind 10 kt. Seas 3 ft.
.THU NIGHT...E wind 10 kt. Seas 3 ft.
.FRI THROUGH SAT...E wind 35 kt. Seas 16 ft.
.SUN...Variable wind less than 10 kt. Seas 3 ft.

$$

PKZ138-091300-
Shelikof Strait-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 8 ft. Freezing spray.
.WED...W wind 20 kt. Seas 5 ft. Freezing spray.
.WED NIGHT...W wind 20 kt. Seas 5 ft. Freezing spray.
.THU...NW wind 15 kt. Seas 3 ft.
.THU NIGHT...NE wind 25 kt. Seas 5 ft.
.FRI THROUGH SAT...E wind 40 kt. Seas 12 ft.
.SUN...Variable wind 10 kt. Seas 2 ft.

$$

PKZ139-091300-
Cook Inlet Kalgin Island to Point Bede-
330 PM AKST Tue Dec 8 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 8 ft.
.WED...S wind 20 kt. Seas 5 ft subsiding to 3 ft in the afternoon.
.WED NIGHT...W wind 20 kt. Seas 4 ft. Freezing spray and patchy
freezing fog.
.THU...NW wind 15 kt. Seas 2 ft.
.THU NIGHT...NE wind 25 kt. Seas 5 ft.
.FRI THROUGH SAT...NE wind 30 kt. Seas 8 ft.
.SUN...NE wind 20 kt. Seas 5 ft.

$$

PKZ140-091300-
Cook Inlet North of Kalgin Island-
330 PM AKST Tue Dec 8 2020

.TONIGHT...S wind 20 kt diminishing to 10 kt after midnight. Seas 3 
ft.
.WED...E wind 10 kt increasing to 15 kt in the afternoon. Seas 3 ft.
.WED NIGHT...Variable wind less than 10 kt becoming W 10 kt after
midnight. Seas 2 ft. Patchy freezing fog.
.THU...NW wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 4 ft.
.SUN...NE wind 10 kt. Seas 2 ft.

$$

PKZ141-091300-
Kachemak Bay-
330 PM AKST Tue Dec 8 2020

.TONIGHT...S wind 20 kt. Seas 3 ft.
.WED...S wind 15 kt. Seas 2 ft building to 4 ft in the afternoon.
Snow showers and rain showers.
.WED NIGHT...W wind 20 kt. Seas 6 ft. Freezing spray and patchy
freezing fog.
.THU...W wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 3 ft.
.SUN...NE wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
600 PM AKST Mon Dec 7 2020

.ANALYSIS AND UPPER LEVELS...

A broad longwave trough remains centered over most of Alaska with
two dominant embedded low centers evident on IR this afternoon.
The first of these consists of a rapidly weakening and vertically
stacked low drifting towards the northern Gulf Coast. A nose of
warm air most prominent near 900 mb has advected into much of
Southcentral with the southeast flow near and to the north of the
low center. The cold air in place at the surface (underneath the
warm layer) resulted in numerous precip type issues this morning
along the Kenai Peninsula, including a disruptive period of
freezing rain in the Homer area before temperatures rose above 32F
by around 9 AM AKST. While temps remain sub-freezing in the
Anchorage vicinity with profiles again supportive of freezing rain
or drizzle, downslope warming/drying has overall prevented precip
streaming in from the PWS from making it into town thus far.

Elsewhere, conditions are deteriorating across the Y-K Delta off
to the north of a second upper level low situated just downstream
of an omega block ridge that continues to spill polar air into
the lion's share of the Bering. Strong northeast winds are
yielding areas of blowing snow combining with a broad band of
falling snow over much of the Y-K Delta and Kuskokwim Bay. Surface
obs from Toksook Bay and Bethel have already indicated winds
gusting to around 35 kts with visibility below 1 statute mile at
times, and blizzard conditions are possible for mainly coastal
sections of the delta region throughout the afternoon and
evening. For the remainder of the Bering, AKPEN and the Aleutians,
areas of convective snow showers rooted in an unstable marine
layer are racing south in the cold advection to the west side of
the low along with plenty of gusty north to northwest winds.

&&

.MODEL DISCUSSION...

Models are in excellent agreement for most synoptic features
through midweek, however, mesoscale details continue to prove
elusive in terms of fully resolving issues with precip type and
location/timing in parts of the Mat-Su Valleys in particular.
Gradual cooling of the overrunning warm layer across Southcentral
is clearly depicted by all reliable models through Tuesday, and
this should result in a changeover from any light freezing
rain/drizzle persisting in the Anchorage Bowl to all snow some
time between tonight and early Tuesday morning. Timing out this
transition may prove a challenge in the immediate term.

In addition to the short term precip type problems, determining
the placement and timing of potentially two rounds of snow between
Tuesday and Wednesday night for parts of the Kenai Peninsula to
Susitna Valley remains difficult. Models show a push of southwest
flow into the area behind the dissipating low as it drifts
inland, likely resulting in a band of snow enhanced by upslope
along and west of the Talkeetna and Chugach Mountains with some
minor model discrepancies persisting for exact locations of higher
amounts. Models differ significantly more with the possible
second round late on Wednesday with the upper low in the Southwest
projected to become part of a very sharp, negatively-tilted
trough that sweeps across the northern Gulf and southern mainland.
The NAM/GFS are currently most optimistic for snowfall for
Wednesday to Thursday with the EC/Canadian more pessimistic
despite what appears to be a favorable setup for a quick but
potentially intense round of snowfall as the trough passes.

&&

.AVIATION...

PANC...VFR conditions are hanging on due to some very dry air in
the low levels and light northerly winds. The thermal profile
still supports the possibility of freezing rain, but there is
little to no precipitation reaching the ground. That will change
later tonight (~10z) when enough precipitation moves in to
saturate the column. This should allow for precipitation to fall,
but exactly what type remains uncertain. There should be a brief
period where a wintry mix reaches the airfield, but that will give
way to all snow. As the snow starts in earnest, expect vis and
cigs to drop into IFR and possibly LIFR range.

&&

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

A very complex weather pattern is expected for Southcentral Alaska
over the next 3 days. The first low that is currently weakening
south of the central Kenai Peninsula is moving northeastward
towards the eastern Kenai Peninsula/western Prince William Sound
will bring a wintry mix of snow with a slight chance of light
freezing rain this evening, turning to all snow overnight. Chances
of precipitation will increase after midnight tonight and
precipitation will become more widespread as the southeasterly
cross-barrier flow across the Chugach Mountains will weaken. This
is important as it will help minimize the amount of downsloping
on the leeward side of the Chugach and thus increase the chance
for precipitation. The combination of cold air advection across
Southcentral and wet bulbing when precipitation becomes more steady
will decrease the temperatures at both the surface and in the
upper levels and thus change any remaining wintry mix to all snow.
Snowfall amounts will generally be 1-3" across the Anchorage Bowl
and across the Mat-Su (including Palmer and Wasilla). However,
locally higher amounts of 2-4" are expected along the Upper
Hillside.

Conditions will become drier late Tuesday morning into Tuesday
afternoon as the first low dissipates. Pressure gradients will be
favorable for a Turnagain Arm wind Tuesday night, though
northeasterly down-inlet flow will keep these Turnagain Arm winds
out of Anchorage which will help keep temperatures cold for the
Anchorage Bowl.

Wednesday will become more active again as the energy from the
aforementioned dissipating low will become absorbed into a
developing low over the AKPEN Tuesday afternoon. This low will
move northeastward into Southcentral for Wednesday. This storm has
the potential to bring another couple inches of snow to the
Anchorage Bowl and the Mat-Su Valley from Wednesday morning
through Thursday morning. The ingredients needed for Anchorage
snow were seen in the past few model runs. The vorticity maxima
(center of counterclockwise circulation) is expected to move
northeastward through Cook Inlet. Meanwhile, the cross-barrier
flow along the Chugach Mountains will remain very weak. All of
guidance shows very weak pressure gradients between Whittier and
Anchorage which will help keep this southeasterly cross-barrier
flow weak. As stated above, weak cross-barrier flow is essential
for precipitation in the Anchorage Bowl because it will help
inhibit the downslope effect in the lee of the Chugach Mountains.
Precipitation type will be less of a concern for the Anchorage
Bowl and Mat-Su Valley with this storm as temperatures will be
cold throughout the duration of the storm. Thus the expected
precipitation type is snow. The biggest area of uncertainty with
this storm is precipitation/snowfall amounts along the southern
Kenai Peninsula as there was significant model disagreement on
precipitation amounts in this area.

With regards to model guidance, the NAM was heavily weighted for
this forecast package for Southcentral Alaska as it had the best
initialization on both the synoptic and thermodynamic situation.
When comparing the GOES-17 water vapor imagery overlaid with MSLP
plots, the NAM had the low center directly over the center of the
low center on satellite. The 12z initialization of the NAM and
NAMNest had very similar vertical profiles with the 12z PANC
sounding. Likewise the 00z frame of the 18z NAM and NAMNest had
the most congruence with the 00z PANC sounding. For the second
storm system on Wednesday, a NAM/GFS blend was used with the NAM
weighted heavier. The biggest disagreement was with the
precipitation amounts, thus that is the area with the most
uncertainty and lowest confidence in this forecast package.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Monday
afternoon through Thursday afternoon)...

A surface low over Bristol Bay is continuing to develop this
evening underneath a now well defined upper level trough. The
heaviest snow and strongest winds will be underneath the occluded
front to the north of the low center. Blizzard conditions have
been observed this afternoon over the coastal areas of the
Kuskokwim Delta and will continue through 5am Tuesday morning.
Snow and blowing snow are also expected for interior areas of the
Kuskokwim Delta with snow accumulations up to 6 inches. Bristol
Bay and the Lower Kuskokwim can expect some snow overnight tonight
and into Tuesday but accumulations should stay below 3 inches.

By Tuesday afternoon the pressure gradient will relax as the low
fills in and begins to move slowly east. This should abate blowing
snow potential as the winds subside. On Wednesday snow is likely
near the western Alaska Range and Lower Kuskokwim Valley as the
upper level low departs to the west. Snow accumulations on
Wednesday should remain below 3 inches with the higher amounts
near the mountains. By Thursday the upper level shortwave will be
to the east with high pressure building in from the west. This
will return clear skies and cold temperatures to the region.

&&

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

An area of low pressure is developing this evening over the
eastern Bering. This will continue the pattern of gale force
winds moving south over the eastern Bering. A Winter Weather
Advisory remains in effect for the Alaska Peninsula from 9pm
tonight to 3pm Tuesday. The wrap around flow to the west of the
low center is expected to bring persistent snow, gusty winds and
blowing snow to the AKPen. Snow accumulations up to 5 inches are
possible with visibilities reduced to one half mile at times. This
upper level wave is expected to move off to the east Tuesday
evening, which will abate the threat of blowing snow.

The hazardous weather threat will then shift to the western Bering
where a storm force low is expected to develop. There is still
some uncertainty on Wednesday with the finer details of this
storm, particularly along the front. A few models have meso-lows
developing and circulating around the primary low. This could
cause localized areas of storm force winds to develop along the
front. On Thursday confidence is moderate and a storm force front
will move across the Bering; however, there is still considerable
model discrepancy in regards to the finer details.

&&

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

Bering: A well-developed Western Bering low merges with a North
Pacific low, forming a new low that moves to the Central Bering
by Sat. Its front sweeps to the Northeastern Bering by Sat. While
model track and development are mixed, widespread high-end gale
force winds and waves wrap the low and front through Sat. The
rear flank winds over the Western and Central Aleutians moves
South and dissipate Sat as the low weakens.

Gulf of Alaska: A weakening low moves across the Northern Gulf
through Thu night. Model track and development vary, but lingering
gap winds bring northwesterly small craft winds and waves over the
Barren Islands into the Western Gulf diminishing Thu. A front
extending across the Alaska Peninsula into the North Pacific moves
into the Gulf through Sat. A well-developed North Pacific low
moves along the front to the extreme southwest corner of the Gulf.
Widespread high-end southeast gale force winds move into the Gulf
becoming easterly across Kodiak Island and the Gulf by Sat.

&&

.LONG TERM FORECAST (Days 3 through 7)...

Models are in decent agreement on a broad vertically stacked low
near the western Aleutians early on Friday with a weakening front
draped across the central/eastern Bering and Aleutians.

On Saturday the Aleutians/Bering storm continues to gradually
weaken, with a new storm system lifting out of the North Pacific
towards the Alaska Peninsula. There is significant disagreement as
to whether this low will bring a front towards the Northern Gulf
Coast, or keeps its impacts primarily just limited to Kodiak and
the AKPEN.

On Sunday this new low looks to retrograde and merge with the
broader low centered in the Bering, with a fairly quiet pattern
setting up for Southcentral which will persist into Monday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard Warning: 155.
Winter Weather Advisory: 181.
MARINE...Gale Warning: 155 175-178 180-185 411 414.
Heavy Freezing Spray Warning: 160 180.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...MSO
SOUTHCENTRAL ALASKA...ED
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CJ
MARINE/LONG TERM...KZ/BG

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
1243 AM AKST Tue Dec 8 2020

AKZ101-111-081700-
Anchorage-Matanuska Valley-
Including the cities of Anchorage, Eagle River, Indian, Eklutna,
Palmer, Wasilla, Sutton, and Chickaloon
1243 AM AKST Tue Dec 8 2020

Periods of light to moderate snow are expected for the morning
commute continuing into the early afternoon hours. That said,
there is still a chance of isolated pockets of light freezing rain
during the early morning hours. Motorists should allow extra time
for their morning commute and use caution while driving.