929
FXAK68 PAFC 060123
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
423 PM AKST Thu Mar 5 2026

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through
3: This afternoon through Sunday afternoon)...

Key Messages:

* Expect a gradual trend towards warmer and cloudier conditions as
  incoming storms begin to break down the ridge of surface high
  pressure over the Mainland.

* We continue to monitor a strong low pressure system moving in
  from this evening into Friday. Potential hazards include heavy
  snow, blowing snow, and, along the Gulf coast, potential for
  snow to mix with or change to rain.

* Multiple winter weather hazards have been issued in
  anticipation of the upcoming winter storm. Advisories are in
  effect from late tonight through late Friday night and/or
  Saturday morning for Cordova, Eastern Kenai Peninsula, Kachemak
  Bay, Susitna Valley, Southern Copper Rover Basin, and Thompson
  Pass. Winter Storm Warnings are in effect for late Thursday
  night through Friday night for the far Western Kenai Peninsula.


Discussion:

A weak low pressure system that brought several inches of snow to
Kodiak Island today is moving northeastward across the northern
Gulf and is opening into a trough. That said, weak easterly flow
across the northern Gulf and Prince William Sound is producing
areas of flurries and light snow showers, and they have made it as
far west as the Anchorage bowl despite the dry airmass currently
in place. Aloft, weak waves are lifting over coastal Southcentral,
providing additional lift in the atmosphere to keep this showery
weather going through this evening.

Elsewhere, a positively tilted 500 mb longwave trough has dug
well southward over the North Pacific, south of the Eastern
Aleutians and the Alaska Peninsula. Downstream of this trough is
an area of upper level divergence, which is helping to deepen a
surface low located south of the Alaska Peninsula with its front
stretching northeastward across the Gulf. Aside from the EC, the
global models are in solid agreement that the low will deepen to
about ~970 mb and approach Kodiak Island by 15z Friday morning,
with a large moisture-rich swath of precipitation associated with
its front lifting northward towards the Gulf coast. The front will
set up a storm force barrier jet paralleling the Gulf coast as
this frontal system begins to close in on the Gulf coast.
Widespread snow breaks out across Southcentral from south to north
Friday morning, with perhaps a modest amount of downsloping
holding snow rates down some for the Anchorage Bowl and northern
Cook Inlet region with the initial push of moisture. Due to the
amount of overrunning moisture with this system, any downsloping
will quickly be offset. For areas like Seward, a flip in wind
direction Friday morning will likely change snow to rain for a
time before a transition back to snow later in the near term.

The key difference today in the models is that the trend has been
more eastward with the track than in the previous days as the
latest runs want to bring the low across the eastern Kenai
Peninsula. If nothing else changes, this sets the stage for
potential deformation banding across the Cook Inlet region as the
upper low component of this system and an upper level disturbance
to the west causes stretching and tilting in the atmosphere.
Pinpointing exactly where this banding could setup is a major
forecast challenge. Trended up today for snow totals for the
windward slopes of the eastern Kenai and Chugach mountains due to
high QPF and upsloping. Gusty winds are expected for a time as
the low continues to move north. Thus, any accumulating snow will
likely result in areas of blowing and drifting snow. Many of the
more inland Winter Weather Advisories incorporate the potential
for blowing snow and reduced visibilities.

As the storm begins to move out of the area, generally expect
improving conditions from Friday night into Saturday. Onshore flow
and an incoming shortwave will lead to continued snow along
Eastern Prince William Sound and the Talkeetna Mountains. In fact,
the latest model runs hint at the overall upper-level trough
stalling over Prince William Sound. If this does happen,
widespread snow showers will remain likely across much of the
coastal mountains as well as the Anchorage Bowl and Mat-Su Valleys
through Saturday. Strong cold air advection and southwesterly
winds across Southern Cook Inlet and Kachemak Bay may also result
in prolonged snow showers for this region. Stay tuned, as this
scenario may result in additional snowfall for areas around Homer
after the main storm system exits to the east.


-AM/TM


&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3/Tonight through Sunday)...

A dry, frigid air remains in place under a northerly flow across
the Kuskokwim Delta and eastern Bering Sea. Cloud streaks are
visible on satellite south of the sea ice edge, spanning south
across the Aleutian Chain. Meanwhile, a deep North Pacific low is
barreling north towards the the southern coastline, from Unalaska
east. This is the low that is the primary hazardous weather maker
through Saturday, as moist air from the south collides with cold,
dense air from the north, for accelerated wind speeds (especially
through the wind-prone areas), snow, blowing snow, and reduced
visibilities across southern Alaska from Unalaska, north and east
towards Bristol Bay and the Lake Iliamna Region. The area that
will be most impacted is the Alaska Peninsula and the Bristol Bay
Coastline with Blizzard Warnings already issued; winter weather
advisories have been issued for Unalaska and Akutan, and areas
across the Bristol Bay Interior and Lake Iliamna. Please visit our
website for more information on the relevant Warnings/Advisories
for your area.

As this low pushes further north and east, its associated cloud
deck will spread across the southwest, and areas that haven`t seen
cloud cover for a few days will lose their sunshine, at least
through the weekend, as most areas note light snow showers with
little accumulation. Another impact of this incoming cloud cover
will be slightly warmer temperatures felt across the northern
Kuskokwim Delta, where wind chill values will flirt with the Cold
Weather criteria overnight tonight...nearing -40F...finally
warming above -30F by mid-morning tomorrow/Friday.

Following the departure of this main storm system from Southwest
Alaska, deep northerly flow will re-establish itself over much of
the Bering Sea and Southwest Alaska. Arctic air will reign
supreme across the eastern Bering and Southwest Alaska, leading to
another period of gusty winds and light snow showers that will
bring us into next week. For communities along the Aleutians and
Alaska Peninsula, light snow showers along with gusty northerly
flow will result in a prolonged period of blowing snow potential
through the weekend, with reduced visibilities and blowing snow
potential through the end of the weekend. Stay tuned.

-AB/CL

&&


.LONG TERM FORECAST (Days 4 through 7 - Monday through
Thursday)...

Upper-level troughing centered over the northern Gulf of Alaska
will extend south into the Northern Pacific, with multiple
shortwaves rotating around the trough. High pressure builds across
the Bering Sea through the forecast period. Strong northwesterly
flow and cold air advection will result in gusty gap winds and
cold temperatures across the Alaskan Peninsula. A tightening
coastal pressure gradient will also create strong winds through
the gaps of the North Gulf Coast. Forecast confidence is high that
both Southwest and Southcentral Alaska will continue to see below
normal temperatures into the middle of next week.

&&

.AVIATION...

PANC...There may be some very light lingering snow showers this
evening but the light snow observed today is mostly over. A strong
low will move south of the Alaska Peninsula around midnight,
spreading moisture north into Southcentral. The low will then
track into the Sound through late Friday evening. Light snow with
some downsloping winds off the mountains combined with gusty north
winds will yield MVFR to IFR cigs and vis through 21Z tomorrow.
As the low gets south of Seward around 00Z the downsloping will
shut of and moderate snow will bring cigs and vis down to IFR and
possibly LIFR. 3-6 inches of snow is expected, but totals may
reach as high as 10 inches.

&&


$$