Winter Storm Warning 3, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
142 PM AKST Wed Jan 15 2025

.SYNOPSIS...
Much colder conditions will settle over the region tonight and
continue Thursday and Thursday evening. Starting late Thursday
and continuing into Friday a warm front will move northwards, not
only bringing in warmer conditions, but producing heavy
precipitation (mainly snow) to much of the west coast and western
interior. The storm system associated with the front will move
into the Bering Sea Friday afternoon and progress northwards
through Saturday and into Sunday. This will bring additional
rounds of heavy precipitation to western areas as well as produce
much stronger winds for the west coast, Alsaka Range passes, and
even throughout the Tanana Valley. This storm weakens by Monday,
but additional systems moving in to the Gulf of Alaska will keep
conditions warmer than normal and a bit unsettled at times next
week.

&&

.DISCUSSION...

Key Weather Messages, Impacts, and Summaries by Region:

Central and Eastern Interior...

- Clearing overnight will allow for our coldest night of the week
  tonight. will likely occur tonight as an arctic high settles in
  with valley locations seeing lows into the -20 F range. Some
  patchy local fog is possible.

- An increasing gradient across the Alaska Range with southerly
  gap winds of up to 50mph winds by Friday. The Tanana Valley Jet
  will increase as well and will blow through the weekend with the
  potential to see winds in the 30 to 50 mph range..

- Temps warm again Friday through the weekend as the cold air
  dome weakens and clouds begin to increase with ridging aloft.

- Chances for snow as a warm front clips the Central Interior
  higher mountains to the Upper Koyukuk Valley on Friday and
  Saturday. Snow will be light with up to 2 inches favoring the
  Upper Koyukuk Valley.

West Coast and Western Interior...

- A strong warm front will usher in a stormy pattern with heavy
  snow, blowing snow, and mixed precipitation for the West Coast
  and Western Interior beginning late Thu night and early Friday.

- Significant blowing snow is likely along the YK Delta Thu night
  and early Friday, spreading north to Nome Friday morning, and
  the Kobuk Valley, Selawik Valley, and Kotzebue later on Friday.

- Heavy snow of 6 to 9 inches of snow is likely by the end of the
  weekend for parts of the West Coast, with 12+ inches for the W
  Brooks Range, Nulato Hills, and higher elevations of the Seward
  Peninsula.

- Gales to 45+ mph for the N Interior valleys to Kotzebue will
  bring near blizzard conditions possible on Friday.

- Nome will see moderate snow and blowing snow with east winds of
  30 to 40 mph.

North Slope and Brooks Range...

 - High pressure settles in with colder temps and benign weather
   through Thursday, with a mix of low stratus and patchy fog to
   liven things up.

- A warm front will bring clouds and east winds along the arctic
  coast with south winds through the passes, along with warming
  temps. Snow will impact the W Arctic coast to Utqiagvik with
  minor blowing snow. Significant warming near the Brooks Range
  Saturday with a chinook flow.

Forecast Analysis and Confidence Discussion...

Relatively quiet weather has settled over much of northern Alaska
as a 1025 surface high pressure has developed over the northern
interior today. This will keep winds relative light for the next
couple of days. At the same time, temperatures will continue to
drop allowing for readings 10 to 15 degrees below normal tonight
through Thursday. Meanwhile our next round of active weather will
be coming together by late Thursday with the most noticeable
impacts likely along the west coast and into portions of the
western Interior Friday and into the weekend.

Currently a vertically stacked closed low is located over the
north Pacific approximately 400 NM south of the Aleutian Chain.
Being vertically stacked will keep this feature primarily
stationary with models indicating only a slow northeasterly drift
over the next 24 to 36 hours. However there is good agreement
between models indicating additional energy from the north Pacific
becoming absorbed by this low and pivoting quickly around the
base and forming a decent 973 surface low to the east of the
primary circulation Thursday night into Friday. This new low will
be the anchor for the upcoming impactful weather event across
western Alaska. This feature will first send a warm front
northwards which will help produce heavy precipitation (mainly
snow) over the YK Delta region early Friday with the precipitation
spreading north and east over the Seward Peninsula and western
interior by Friday evening. Meanwhile the surface low will be
tracking north through the Bering Sea Friday and Saturday keeping
these same regions under a threat for significant precipitation.
However over the past few model runs there has been a trend to mix
the precipitation with rain or even change it to all rain over
the YK Delta Saturday and models are now hinting that portions of
the Seward Peninsula will also see a changeover to rain.
Confidence is rather high for a changeover over the YK Delta, but
more uncertainty arises with precip type over the Seward
Peninsula. We will keep the Winter Storm Watch in place for
locations that are expecting to see the most snowfall (including
Nome for now) as well as Winter Weather Advisories elsehwere
along the west coast where the initial snowfall will combine with
increasing winds to create a good chance for considerable amounts
of blowing snow in the early stages of this storm.

Another change that we have noticed is a trend for the models to
weaken the surface low a bit as it moves through the Bering. A
weaker low will mean somewhat lower wind speeds as the gradient
will be slightly less. However winds will still be strong enough
to result in blowing snow and an impactful east wind of 30 to 40
mph or more near Nome remains in this forecast package.

Winds will also increase across the Alaska Range and through the
passes thanks to this system. This situation will be monitored by
future shifts to see if eventual wind advisories may be necessary
for the passes for Friday. And finally, with the surface high
shifting east as the low tracks up the Bering, models are keeping
a decent east-west gradient over the Tanana Valley where we
anticipate a stronger TVJ to form by Friday as well.

Extended Forecast Days 4-8...

Very high amplitude ridging aloft will be in place over the E
Interior and Yukon and across the Gulf on Saturday. The height
field ridge/trough will extend from around 30N to 80N over the
high arctic, which would put this amplification into the "extreme"
category. Initially, it will be dry over the E Interior and very
stormy out west, through the weekend. Eventually the upper high
will buckle and there will be chances for precipitation over the E
Interior sometime late Sunday into Monday. Heavy snow and mixed
precipitation will be a constant for the West Coast/Interior all
the way through the week, with warm anomalies dominating the
entire state. This pattern looks to stick well into the latter
half of this month with no major arctic intrusions in sight as
the stratospheric vortex shifts into the lower half of North
America.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ816-818-819.
     Winter Storm Watch for AKZ817.
     Winter Weather Advisory for AKZ820-821-824.
     Winter Storm Watch for AKZ822-823.
     Winter Weather Advisory for AKZ825-826.
     Winter Storm Watch for AKZ827.
     Winter Storm Watch for AKZ829-830.
PK...Brisk Wind Advisory for PKZ806-807-854.
     Brisk Wind Advisory for PKZ810-811-857.
     Brisk Wind Advisory for PKZ816-817-853.
     Brisk Wind Advisory for PKZ850.
     Brisk Wind Advisory for PKZ851.
     Heavy Freezing Spray Warning for PKZ855.
     Brisk Wind Advisory for PKZ856.
&&