Storm Warning 22, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
346 PM AKST Sun Nov 17 2024

.SYNOPSIS...Drier conditions expected across much of northern
Alaska through Monday as dry and very cold air pushes southward
across the state. Mostly clear skies and a building ridging
Tuesday and Wednesday will allow for widespread low temperatures
of 20 to 30 below, with the well known cold spots of Chicken and
Fort Yukon near 40 below. A low pressure system moves east out of
Siberia and across the Chukchi Sea by early next week, bringing
strong and gusty onshore winds, moderate to heavy snow, and
potential for blizzard conditions to portions of the Seward
Peninsula and Arctic Coast late Monday night through Wednesday
night. There's also growing confidence in a short period of
freezing drizzle and/or freezing rain across the Y-K Delta and
northward to the Seward Peninsula and as far inland as Galena by
Tuesday morning.

&&

.DISCUSSION...

Central and Eastern Interior Key Messages...
- Drier conditions and clearing skies expected today with temperatures
  turning much colder tonight through Monday/Tuesday.
- Temperatures drop to 30 below tonight across the Upper Koyukuk Valley.
  These cold temperatures drop further south to the Tanana Valley
  by Monday night into Tuesday.
- Moderate north winds on the south side of the Alaska Range
  Monday and Monday night will support the development of areas
  of blowing snow, reducing visibility to one half mile or less at
  times, supporting a Winter Weather Advisory.
- A front brings rapidly warming temperatures and light snow chances
 Tuesday night through Wednesday.

North Slope and Brooks Range...
- Cold temperatures (around -30F) become more widespread through Monday
  night across the Arctic Plains and Brooks Range. North winds
  around 15 mph in the Brooks Range tonight into Monday morning
  will result in very cold wind chills near 50 below, short of a
  Cold Weather Advisory.
- Winds shift westerly tonight into Monday resulting in an
  increase in sea effect snow showers downwind of the Chukchi Sea
  and stronger west winds of 30-40 mph will result in blowing
  snow for Barter Island/Kaktovik, justifying a Blizzard Warning.
- A strong warm front brings a period of snow and strong south to southwest
  winds to the Chukchi and western Arctic Coast Monday night into
  Tuesday, justifying Blizzard Watches.

West Coast and Western Interior...
- From the Seward Peninsula south to the Y-K Delta and east
  towards the Lower Yukon Valley, a mix of precip is expected
  Monday night into Wednesday with a glaze of ice possible. Ice
  accumulations up to a glaze will be possible for southern
  portions of the Seward Peninsula, therefore a Winter Weather
  Advisory has been issued.
- Sea effect snow showers in the vicinity of Emmonak will
 gradually taper off to flurries through this evening.
- Strong southerly winds accompanied by moderate to heavy snow may
  result in blizzard conditions along the Bering Strait coast
  between the Seward Peninsula to Point Hope Monday night into
  Wednesday.

Broad upper level troughing prevails across mainland Alaska as an
embedded mid lvl short-wave trough over southwest Alaska continues
to drop southeast into the Gulf of Alaska through this evening. Snow
will taper off across much of northern Alaska through this evening
as drying mid-levels combined with a building ridging over the
Aleutian Chain eastward will allow for skies to clear as winds turn
northerly, with the exception of the western Y-K Delta where sea-
effect snow showers continue.

A weakening upper level low west of Banks Island continues to push
cold air south across the Interior tonight into Tuesday. Meanwhile
strong ridging builds north out of the Aleutian Chain and North
Pacific with the ridge axis stretching from near Amchitka through
the Bering Strait and into the Chukchi Sea by Monday afternoon. Very
cold overnight temperatures are expected tonight, with temperatures
dropping into the 30 below range over the Arctic Plains to the
Upper Koyukuk Valley tonight. These very cold temperatures will be
accompanied by northerly winds around 15 mph in the Brooks Range
dropping wind chill values to near 50 below. By Monday night,
these very cold temperatures drop further south across the
Interior with low temperatures near 40 below at Arctic Fort Yukon
and Chicken and 25 to 30 below across the Tanana Valley.

A deepening low tracks north across eastern Siberia and over the
Chukchi Sea, Monday night into Tuesday. Model guidance continues to
prog a stout mid to upper lvl ridge which may limit the amount of
snowfall for the Seward Peninsula as the strong warm front shifts
over the West Coast by late Monday night. The front then lifts
northeast across the Interior Tuesday night into Wednesday. Strong
southerly winds develop along the Bering Strait and Chukchi Sea
coasts, which combined with falling snow continue to signal
potential blizzard conditions. In addition, localized ice shoves are
a possibility with the new ice starting to form along the Northern
Kotzebue Sound. From St Lawrence Island east to the Lower Yukon
Valley and south to the Y-K Delta there is the potential for
freezing drizzle. Further into the interior the front may be
completely dry with better chances for precip with the cold front
late Wednesday or Thursday.

Extended Forecast Days 4-7...There still remains a good deal of
spread in model and ensemble solutions with a low and associated
front that moves out of Eastern Russia and across the Chukchi Sea
through early next week. While all solutions continue the same
trend, there remains a lot of spread in track and speed. The 17/12Z
runs continue the trend of strengthening the ridge pushing north out
of the North Pacific, which in turns keeps pushing the low further
north. The northward trend pushes precip further north, cutting
amounts from the Seward Peninsula south by more than half. This
solution would limit precip at Kotzebue, lowering blizzard potential
there. Nevertheless, still expect strong winds north of the Seward
Peninsula and potential blizzard conditions along the Chukchi Sea
Coast and Bering Strait coast. By Wednesday the upper ridge should
become flattened a bit as an upper low moves east over the Arctic.
This will bring more of a westerly flow pattern that will push the
front and accompanying snowfall across northern Alaska.

Coastal Hazard Potential Days 3 and 4...Strong southwest to west
winds develop into Tuesday and persist into Wednesday from Point
Hope east to Utqiagvik. These winds will result in the potential
for elevated water and beach erosion along the coast. At this
time, there remains a large amount of uncertainty with the
details.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Watch for AKZ801-814>817-820-821.
     Winter Weather Advisory for AKZ848-850.
     Winter Weather Advisory for AKZ822.
     Blizzard Warning for AKZ805.
PK...Small Craft Advisory for PKZ801-853.
     Heavy Freezing Spray Warning for PKZ801-805-853-854.
     Brisk Wind Advisory for PKZ802.
     Small Craft Advisory for PKZ805.
     Small Craft Advisory for PKZ806.
     Heavy Freezing Spray Warning for PKZ806-807-817-856.
     Small Craft Advisory for PKZ807-856.
     Brisk Wind Advisory for PKZ814-860.
     Gale Warning for PKZ815.
     Small Craft Advisory for PKZ816-817-851-854.
     Heavy Freezing Spray Warning for PKZ816-850.
     Gale Warning for PKZ850.
     Heavy Freezing Spray Warning for PKZ852.
     Gale Warning for PKZ861.
&&