Blizzard in Alaska, February 17, 2023

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
248 PM AKST Thu Feb 16 2023

.SYNOPSIS...Strong winds across the Arctic Coast will finally begin
to weaken this evening as the surface pressure gradient slackens.
Pockets of light snow across the interior will increase in coverage
spreading northeast from McGrath to north of Fairbanks with only
light accumulations expected. A strong low pressure system is coming
onshore across the Alaskan west coast which will spread winds and
accumulating snow through the YK Delta, into the Western Interior
and Interior into Friday. Another, weaker system follows in the wake
of the first low, reinforcing snow chances through the interior
Saturday.

&&

.DISCUSSION...
Overall pattern in place involves broad weak low pressure aloft from
the Chukchi Sea through the Interior. Another weak shortwave will
lift through this broader trough tonight generating light snow
through the interior. Models seem to have a pretty good handle on
this. Meanwhile a deeper cut-off 492 dam low stationed near the
western end of the Aleutian Islands will eject more vigorous
shortwaves into the West Coast through Saturday, the first one
arriving tonight.

Latest model guidance seem to have initialized well when compared
with the latest 12z RAOB data. Subtle differences exist in the
overall depth of the shortwave troughs as they eject from the parent
low and push towards the YK Delta.

North Slope and Brooks Range...
Surface high pressure over the northern Beaufort Sea will
continue to erode today as broad low pressure establishes control.
This will allow for the gradual relaxing of the pressure gradient
along the Arctic Coast from Barter Island through Point Thomson.
Expecting winds to weaken allowing lowered visibilities to ease
and wind chills to moderate by late tonight. Elsewhere, we're
expecting a mix of sky conditions as clouds will begin to stream
into the eastern North Slope this evening. Expect low temperatures
in the 20s below for most locations however a few inland
locations will drop into the 30s below. Highs on Friday will be in
the single digits above and below for locations through the
Brooks Range, teens to near 20 below through the Arctic Plain and
along the Arctic Coast.

Central and Eastern Interior...
Broad low pressure through the interior and weak troughing aloft
has led to increased cloudiness through the interior today, mixing
in a few pockets of snow, primarily west of Fairbanks. Snow near
Tanana will lift north into the Yukon Flats this evening. Little
additional accumulation is expected. As low pressure is reinforced
by the advancing low through the West Coast, surface winds will
increase from the Alaska Range and through upper reaches of the
Tanana Valley. Remnant moisture from the low moving into the West
Coast will arrive into the southern Interior late tonight into
early Friday. Light accumulating snow is expected for most
locations throughout the Interior. The Alaska Range and higher
elevations along the Yukon River near Tanana could see 2-4 inches
of snow. Clouds and light snow will then continue for most in the
Interior Saturday as another, weaker low pressure system moves
through the southern Interior. With the added moisture and clouds,
temperatures will moderate, especially overnight tonight where
lows will generally range from near zero to teens below. Highs on
Friday will tick up a few degrees with most location outside of
the Yukon Flats above zero. The southern Interior could even see
teens above.

West Coast and Western Interior...
Already seeing snow arrive in coastal areas of the YK Delta
associated with the first of two low pressure waves that will
advance through over the next 48 hours. Still looking at around
2-4 inches of snow along the west coast tonight into Friday. In
addition to the snow we'll see winds increase this evening leading
to blizzard conditions in the YK Delta south and west of Anvik.
Snow and blowing snow will lead to near whiteout conditions in
coastal areas and around the southern reaches of Norton Sound.
Gradual improvement is expected Friday evening, but another wave
of low pressure will arrive Saturday, reinforcing snow chances and
increasing winds again. Additional or extended Advisories or
Warnings may be needed during this time. The additional moisture
and surge of warmer air will allow temperatures to moderate.
However, the increasing winds will keep cold wind chill readings,
especially along exposed coastal areas.

Extended forecast for days 4 to 7...
Models continue to call for a building ridge over the Interior
into next week with considerable agreement in the broad details.
This is expected to lead a warming trend into next week, but also
puts the West Coast and Western Interior into southwest flow
aloft, which will lead to more precipitation activity over the
coming week. Finer details still need to be worked out, but the
system next week should be followed for potential impactful
weather including accumulating snowfall and even the chance for
rain or freezing rain into the Interior.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ212.
     Winter Weather Advisory for AKZ213.
     Blizzard Warning for AKZ214.
     Winter Weather Advisory for AKZ215.
     Winter Weather Advisory for AKZ204.
PK...Brisk Wind Advisory for PKZ200.
     Gale Warning for PKZ201.
     Gale Warning for PKZ210.
     Brisk Wind Advisory for PKZ220.
     Brisk Wind Advisory for PKZ225.
     Brisk Wind Advisory for PKZ240.
     Gale Warning for PKZ245.
&&