Blizzard and Heavy Snow in Alaska, December 11 to 13, 2024

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
255 PM AKST Wed Dec 11 2024

.SYNOPSIS...Busy forecast with a number of impactful systems
forecast to move across the forecast area over the next few days.
High pressure in the Arctic will bring Blizzard conditions to the
Arctic Coast this afternoon through Friday. A front moving northwest
from the Gulf of Alaska will form into a deformation band over
the Central and Eastern Interior on Thursday and Friday. This will
bring 3-6 inches of snow to valley locations and up to 8 inches at
higher elevations, though forecast uncertainty as to where the
heaviest snow will fall is extremely high. Temperatures cool back
below freezing overnight tonight and Thursday over the West Coast.
Expect standing water from the recent rain and warm conditions
there to freeze.

&&

.DISCUSSION...

KEY MESSAGES...

CENTRAL AND EASTERN INTERIOR...
- Above-normal temperatures expected to remain through the week,
  but gradually cooling daily through the end of the week as snow
  chances return.

- A front moving northwest from the Gulf of Alaska will form into
  a deformation band over the area on Thursday and Friday. There
  is still a lot of uncertainty as to where the heaviest snow sets
  up, but Winter Weather Advisories have been issued from
  Minchumina to Tanana to Fairbanks to Delta Junction to Eagle for
  a widespread 3 to 6 inches of snow. Some areas may see up to 8
  inches, though that will most likely be in the Fortymile uplands
  or near Farewell Lake. Fairbanks has a 15% chance of seeing
  over 6 inches.

- Snow will likely start out as somewhat wet and slightly heavier
  than normal snow, but transition to light, fluffy snow toward
  Friday afternoon.

- An arctic cold front will bring seasonably cold temps to much of
  the area over the weekend with highs dropping to below zero and
  lows dipping into the 20s and 30s below zero.

WEST COAST AND WESTERN INTERIOR...
- Warm and windy conditions continue today. This will lead to very
  messy snow conditions and difficult travel conditions.

- Temperatures cool back below freezing overnight tonight and
  Thursday. Temperatures drop to near or below normal Saturday and
  Sunday. Expect standing water from the recent rain and warm
  conditions to freeze.

- Quiet conditions with light snow showers mainly near the Seward
  Peninsula and points south Thursday and Friday.

- Breezy easterly winds Saturday and Sunday.

NORTH SLOPE AND BROOKS RANGE...
- Freezing fog near Deadhorse this morning is causing light
  accumulations of ice on surfaces.

- Storm force easterly winds develop Wednesday night through
  Thursday night when blizzard conditions are expected east of
  Point Lay, especially near Deadhorse. This will likely be an
  extended period of hazardous conditions with low visibility and
  extensive blowing snow that may last through the weekend.
  Blizzard warnings have been issued through Friday.

Analysis and Forecast Confidence...Very challenging forecast today
with a number of impactful systems across the forecast area and
very poor model agreement on a few of them. To start, Blizzard
Warnings have been issued for the Arctic Coast for this evening
through Friday due to a strong arctic high that has formed over
the eastern Beaufort Sea. The forecast for this high has weakened
with each sequential model run and is now forecasted to be around
1041 mb this afternoon at the onset of blizzard conditions, down
from 1043 mb during yesterday's model runs. The result of this is
slightly weaker forecast winds, though winds will still likely
gust to 65 mph in spots especially near Deadhorse. Freezing fog
this morning near Deadhorse has likely created a crust over the
snowpack, so blizzard conditions may take a little bit longer to
develop than expected.

Low pressure persists over the Bering Sea and in the Gulf of
Alaska. A front will move north over the Alaska Range and form a
deformation band in the central and eastern Interior tomorrow. The
question is where exactly this will form. Yesterday's model runs
were in good agreement for the heaviest snow to be southeast of
Delta Junction. Today's model runs are all showing snow much further
northeast, likely due to the weaker high in the Arctic. The front
is basically allowed to move further north before it runs into
the high and turns around and heads back south. However, model
runs are all showing different solutions on precipitation
placement and amounts. Despite recent warm temperatures, expect
all snow for the precipitation type. There is a very slight chance
that precipitation may start as freezing drizzle at Delta
Junction for less than one hour on Thursday morning before
transitioning to snow.

For the forecast today, we've issued Winter Weather Advisories for
snow amounts across most of the central and eastern Interior. The
highest confidence area for 6+ inches of snow is Nenana to Tanana
to Minchumina. Areas southeast of Delta Junction now appear that
they will receive less snow. For Fairbanks, model solutions range
from 1 inch to over 6 inches of snow for Thursday and Friday.
There is a very high probability that Fairbanks will see snow. We'll
use a blend of models for the forecast, but the bottom line is
that forecast confidence for snow amounts is very low. As little
as 1 inch to over 8 inches are all possible. Expect snow to start
out wetter and heavier before turning fluffy Friday evening.

Extended Forecast for Days 4 Through 7...The extended period will
begin Saturday evening with a deep closed upper level low over
the eastern Interior. This will help cold temperatures continue
until the low quickly exits the forecast area to the west on
Tuesday morning. After this, a return to Chinook or modified
Chinook conditions looks likely. This will bring temperatures back
to above normal across most of the forecast area by the middle to
end of next week. Precipitation will be limited with most areas
staying dry next week.

Coastal Hazard Potential Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Blizzard Warning for AKZ801>803.
     Blizzard Warning for AKZ804-805-808.
     Winter Weather Advisory for AKZ835-837>846.
PK...Brisk Wind Advisory for PKZ802-855.
     Small Craft Advisory for PKZ804-809-850.
     Brisk Wind Advisory for PKZ805-852-856.
     Small Craft Advisory for PKZ807.
     Brisk Wind Advisory for PKZ811.
     Brisk Wind Advisory for PKZ812-857-858.
     Gale Warning for PKZ813-859.
     Gale Warning for PKZ814-815-860-861.
     Small Craft Advisory for PKZ816-851-854.
     Small Craft Advisory for PKZ817.
     Brisk Wind Advisory for PKZ853.
&&

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