558
FXAK69 PAFG 231519
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
619 AM AKST Thu Jan 23 2025

.SYNOPSIS...A high impact weather pattern continues to evolve
across northern Alaska as a parade of storms moves up the West
Coast. The most impactful storm arrives late today, bringing high
winds, heavy snow above 1000 ft elevation, blowing snow, and low
elevation rain to the West Coast and Western Interior before
pushing into the Central and Eastern Interior Friday through the
weekend. Very heavy wet snow is expected from McGrath to Tanana
to Bettles, with snow mixing with rain at times especially east of
this line. Very cold temperatures, possibly the coldest thus far
this winter, will follow this system and settle across the area by
the middle of next week.

&&

.DISCUSSION...
Key Weather Messages:

Central and Eastern Interior...

- Much warmer than normal temperatures continue with highs mostly
  in the 20s before most areas reach the 30s to near 40 on Friday
  and over the weekend.

- Heavy wet snow begins late Thursday night and continues through
  Friday, mainly north and west of Fairbanks. By Friday evening,
  over a foot of snow is expected at higher terrain along the
  Dalton Highway between the Yukon River and Atigun Pass.

- Heavy snow is also expected across the south slopes of the
  Alaska Range from Cantwell to Trims Camp and across the Denali
  Highway. Snow amounts of 12-20 inches are expected through
  Sunday morning.

- Ahead of the cold front, southerly gap winds may reach 75 mph
  through Alaska Range passes Friday and Saturday.

- Southerly winds may gust to 60 mph over Twelvemile and Eagle Summits
  Thursday night into Friday.

- A NE to SW oriented cold front stalls across the interior this
  weekend with heavy snowfall west of the front likely. Confidence
  is the position of the front is increasing, with it likely
  setting up just east of Tanana. Light rain is expected to mix
  with snow along and east of the cold front.

- Behind the cold front, very cold temperatures -possibly the
  coldest of the winter so far- are expected by the middle to end
  of next week. Lows may reach the -40 to -50 F range across much
  of the area with only a weak inversion due to a very cold
  airmass.

West Coast and Western Interior...

- A potentially high-impact storm brings strong winds, heavy snow,
  and heavy low-elevation rain Thursday into Friday as the storm
  quickly lifts northeast. Southerly gusts over 60 mph are
  possible, but temperatures near to above 32F should temper
  blowing snow impacts. Another foot of snow is possible along the
  Nulato Hills, Seward Peninsula and Kobuk Valley. Numerous
  warnings and advisories have been issued.

- Water is expected to come up through cracks in the sea ice and make
  travel over the sea ice very difficult for much of the West
  Coast.

- More seasonable temperatures return Sunday.

North Slope and Brooks Range...

- Well above normal temperatures continue through Saturday.

- Very strong south winds gusting 50 to 60 mph are expected
  through Brooks Range Passes on Friday and Saturday, with winds
  likely extending north to Toolik Field Station. Expect
  significant blowing snow.

- Strong winds and snow will begin to develop over the western
  north slope and Brooks Range on Friday as a strong low pressure
  system and tight gradient swiftly moves across the area.
  Southwest winds gusting as high as 75 mph are possible Friday
  evening when blizzard conditions are possible from Point Hope to
  Wainwright.

- More seasonable temperatures return to the area Sunday through early
  next week when a wave of light snow is possible across the
  eastern North Slope.

Forecast Analysis and Confidence...A 976 mb low has moved into the
Gulf of Anadyr with a long occluded front stretching from eastern
Siberia to Eastern Norton Sound. Snow is falling along this front
and it will continue north to the Western Arctic Coast through the
day today. This is the middle system sandwiched between 3 storm
systems to move into the Bering Strait region. The third system
will be the strongest storm as a strong gradient will form with
high pressure building to 1048 mb in the Gulf of Alaska by Friday
morning. The third storm will move to St. Paul Island at 987 mb
this afternoon with a moisture laden leading front bringing high
winds, heavy rain and snow to the West Coast and Western Interior
this evening and overnight into Friday. This storm is a quick
mover, and will bring short periods of very high winds from the
Yukon Delta all the way to Utqiagvik through Friday evening. A
storm south of the Aleutians will then form an inverted trough
over southwest Alaska, allowing an Atmospheric River/Pineapple
Express to moved abundant moisture and warm air into the Interior
from as far south as Hawaii. This front will become nearly
stationary through Sunday, with very heavy precipitation expected
along the front, which will form along a boundary between the
Arctic Front and the strong building ridge over the Gulf of
Alaska. The heaviest precipitation is expected from McGrath to
Tanana to Bettles, with 14 to 24 inches possible through Saturday
night. Rain may mix in at times Friday night and Saturday. Further
east of the Arctic Front near Fairbanks, expect more rain than
snow Friday night through Saturday, though precip amounts will be
substancially less due to south winds through Alaska Range Passes
creating a dry slot. The Arctic Front then pushes east Monday and
Tuesday, with more snow expected as it comes through the Eastern
Interior. Very cold temperatures, possibly the coldest of the
year, will set in by the middle of next week behind the Arctic
Front. Also within this system, strong gradients will form across
Brooks and Alaska Range Passes, causing very strong gap winds as
high as 75 mph through Alaska Range Passes late Thursday night
through Saturday and as high as 60 mph through Brooks Range Passes
on Friday.

Models have come into much better agreement on the positioning of
the heaviest precipitation from the Pineapple Express with 1.5 to
3 inches of liquid equivalent expected from Chandalar Shelf to
Bettles to Tanana to McGrath through Tuesday. That said, it is
likely that the heaviest precipitation will be west of Fairbanks.
For areas beneath the area of heaviest precipitation,
precipitatable water anomalies will be 4 to 5 standard deviations
above normal for this time of year. Ensembles are still showing
the potential for wind gusts up to 75 mph, particularly from
Point Lay to Utqiagvik.

Extended Forecast For Days 4 Through 7...Heavy precipitation
continues Sunday and Monday across a large swath of the Interior
as well as the Brooks Range and Arctic Coast. A deep upper level
low will swing southeast from northern Russia on Monday, bringing
a very cold airmass that will persist across the area through next
week and into the weekend. The coldest temperatures of the year
thus far are certainly possible, with deterministic models
consistently hinting at lows in the -40 to -50 F range across the
Interior from the middle of next week through next weekend. Expect
breezy north/northwest winds across the West Coast to create very
cold wind chills.

Coastal Hazard Potential Days 3 and 4...None. With water expected
to push through cracks in the ice with the upcoming storm later
today and tomorrow, expect travel on sea ice to be difficult
across most of the area.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Warning for AKZ801>803-806-807.
     High Wind Warning for AKZ847-849.
     Winter Weather Advisory for AKZ850.
     Winter Storm Warning for AKZ851.
     Winter Storm Warning for AKZ830-852.
     Winter Storm Warning for AKZ812-831-832.
     Winter Storm Warning for AKZ813-819.
     Winter Storm Warning for AKZ814.
     Winter Weather Advisory for AKZ822-824.
     Winter Storm Warning for AKZ823.
     Winter Storm Warning for AKZ825.
     Winter Weather Advisory for AKZ826.
     Winter Storm Warning for AKZ829-846.
     Winter Storm Watch for AKZ804-805.
     Winter Weather Advisory for AKZ834.
     Winter Weather Advisory for AKZ838-841>845.
     Winter Weather Advisory for AKZ848.
     High Wind Warning for AKZ809.
PK...Gale Warning for PKZ801-850.
     Heavy Freezing Spray Warning for PKZ801.
     Gale Warning for PKZ802.
     Gale Warning for PKZ803.
     Gale Warning for PKZ804-805-852.
     Brisk Wind Advisory for PKZ806.
     Brisk Wind Advisory for PKZ807>810-817-851-854>856.
     Brisk Wind Advisory for PKZ811-812-857.
     Brisk Wind Advisory for PKZ813.
     Brisk Wind Advisory for PKZ816.
     Gale Warning for PKZ853.
     Brisk Wind Advisory for PKZ858.
     Brisk Wind Advisory for PKZ859.
     Brisk Wind Advisory for PKZ860.
&&

$$

CHRIEST