191
FXAK69 PAFG 181313
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
413 AM AKST Sat Jan 18 2025

.SYNOPSIS...

After a stormy day for the West Coast conditions will slowly
improve this morning for a brief period as dry air encroaches the
mid levels today. Heavy snow has transitioned to a rain/snow mix
for the southern Seward Peninsula and will continue through the
afternoon. Tonight more heavy snow is on tap for the Southern
Seward Peninsula, Nulato Hills, Kobuk Valley. Southerly flow on
the North Slope and Eastern Interior will bring temperatures 20 to
30 degrees above normal. High pressure will continue to
strengthen over the Northwestern Territories of Canada, which will
bring continued southerly gap winds through the Alaska Range
passes and a Tanana Valley Jet through Sunday.

&&

.DISCUSSION...

Key Weather Messages:

Central and Eastern Interior...

- Temperatures will be warming into the 20s tomorrow and will
  persist through the remainder of next week.

- Southerly gap winds through the Alaska Range will continue today
  with gusts up to 65 mph, and begin to weaken overnight tonight.
  Tomorrow there could be occasional gusts up to 50 mph through
  Isabell pass.

- A weak Tanana Valley Jet will continue through Monday night.
  Delta Junction is gusting at 30 mph currently and is expected to
  stay around that strength. Nenana is seeing gusts of 25 mph and
  will slowly weaken tomorrow as the gradient over Nenana weakens.

- Snow chances will return to the interior Sunday night. The
  highest chances will be in a corridor from Tanana to the White
  Mountains. Fairbanks has a chance to see some light
  accumulations associated with the shortwave.

West Coast and Western Interior...

- There will be another round of heavy snow this afternoon for the
  Southern Seward Peninsula, Nulato Hills, and Kobuk Valley with
  an additional accumulations of 6 to 10 inches through tomorrow.

- The Y-K Delta will see continued light rainfall through today
  until transitioning back to snow tonight. Snow accumulations
  will be light with an additional 1 to 3 inches expected
  overnight.

- Easterly wind gusts up to 45 mph in Norton Sound and Kotzebue
  sound will continue until Sunday morning as they begin to weaken
  and turn southerly then westerly.

North Slope and Brooks Range...

- Chinook flow will begin today bringing unseasonably warm
  temperatures from the Brooks Range to the Arctic Coast.
  Temperatures will be in the 20s above on the coast and near
  freezing on the Arctic Plains.

- Atigun Pass and Anaktuvuk Pass will have southerly gap winds up
  to 40 mph. There could be blowing snow throughout the weekend
  from Atigun pass and along the Dalton Highway to Sagwon.
  Visibilities could be as low as 1/2 mile in some spots.

- Point Hope will see additional snow accumulations up to 4". As
  winds shift southeasterly Saturday there may be periods of
  reduced visibility from blowing snow. Wind gusts up to 45 mph
  are possible through Sunday PM.


Forecast Analysis and Confidence...

A 980 mb low is roughly 100 miles east of St. Paul Island will
keep weakening as it moves to the north and the vorticity max get
stretched in the shortwave trough. At 700 mb there is a a dry slot
associated with this low. This will remove moisture from the DGZ
at Nome. With no ice crystals in the cloud the snow will
transition to either a drizzle as there is still enough low level
moisture, or will stop precipitating for some time. A secondary
surface low will begin to spin up this afternoon near Unalaska.
This will bring moisture advection into the mid-levels at Nome
allowing for heavy snowfall to resume tonight.

Monday evening another 985 mb surface low will spin up near
Unalaska and move into Bristol Bay by Tuesday evening. This will
bring another round of snow showers to the Y-K Delta and southern
Seward Peninsula.

Sunday night a shortwave will begin to move through the Interior
and will push the ridge to east allowing for southwest flow in the
Interior. This would allow for moisture to be advected from the
Bering Sea bringing us our snow chances for the Interior. There is
still some model disagreement on the amounts for snow, but
snowfall should remain light. After this shortwave moves across
the Interior, southerly flow will return for a few days. We could
see a brief cool down with this shortwave as 850 mb temperatures
drop to -6 to -10 degrees. Once southerly flow returns we will
return to 850 mb temps of -0 to -2 degrees which is what we are
currently experiencing with our warm up currently.

Extended Forecast Days 4-8...

Ridging over the Eastern Interior will continue through the week
as a series of lows go through the Bering bringing additional snow
chances in the week. Thursday and Friday can see a potential
change in the overall longwave pattern as a potentially strong low
moves into the Bering and would weaken the ridge over the eastern
part of the state. There is still a lot of uncertainty of what
this would bring to the Eastern Interior. The ECMWF and Canadian
brings in an Arctic Front across the interior while the GFS keeps
the low in the Bering, but weakens the southerly flow.



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

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ849.
     Winter Weather Advisory for AKZ813-814-816-818-819.
     Blizzard Warning for AKZ817.
     Winter Storm Warning for AKZ822-823.
     Winter Storm Warning for AKZ829.
     Wind Advisory for AKZ847.
     Winter Weather Advisory for AKZ808.
PK...Gale Warning for PKZ801-850.
     Gale Warning for PKZ802.
     Gale Warning for PKZ803.
     Gale Warning for PKZ804.
     Brisk Wind Advisory for PKZ805.
     Gale Warning for PKZ806-853-854.
     Gale Warning for PKZ807-808-855.
     Gale Warning for PKZ809.
     Gale Warning for PKZ810-856.
     Gale Warning for PKZ811.
     Brisk Wind Advisory for PKZ812.
     Brisk Wind Advisory for PKZ813.
     Brisk Wind Advisory for PKZ814.
     Brisk Wind Advisory for PKZ816-851.
     Brisk Wind Advisory for PKZ817.
     Gale Warning for PKZ852.
     Gale Warning for PKZ857.
     Brisk Wind Advisory for PKZ858.
     Brisk Wind Advisory for PKZ859.
     Brisk Wind Advisory for PKZ860.
     Brisk Wind Advisory for PKZ861.
&&

$$

Dennis