989
FXAK69 PAFG 311447
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
647 AM AKDT Mon Aug 31 2026

.SYNOPSIS...
A cold, wet, and windy start to the week will give way to a brief
break Tuesday before renewed rain and wind returns from the West on
Wednesday. The Chukchi Sea low will move further southeast across
the Interior on Monday bringing continued rain to the southeastern
Interior, gusty winds, and accumulating wet snow in the Alaska
Range. Showers will decrease Tuesday as the low pulls away and high
pressure builds across the Interior, while cooler and showery
conditions continue to linger across the North Slope. By Wednesday,
a strengthening low pressure system in the Bering Sea will bring
renewed widespread rain and increasing winds to the West Coast.

&&

.KEY MESSAGES...
Central and Eastern Interior...

- Wet snow in the Alaska Range today. Snow levels will fall to
  around 2,000-2,500 feet with 3 to 7 inches possible along the
  Richardson Highway near Isabel Pass and locally higher
  amounts at higher elevations.

- Cool, wet, and windy weather continues through today. Showers
  will affect much of the Interior today, with gusty west to
  northwest winds, especially in exposed areas and higher
  terrain. Heaviest precipitation coverage is expected to shift
  further southeast today into the Upper Tanana Valley with
  totals ranging from 0.10-0.50 inches. Strongest winds expected
  through the Tanana Valley with gusts up to 35 mph possible.

- Cool conditions continue through today with highs generally in
  the 40s and 50s and overnight lows in the mid 30s to low 40s.
  Clearing overnight tonight will allow for some valleys to fall
  near freezing temperatures on Tuesday morning. Temperatures
  are expected to warm through Wednesday with highs in the mid
  to upper 50s across most of the Interior, with locally lower
  temperatures in the southeast temperatures where cloud cover
  and showers are expected to linger.

West Coast and Western Interior...

- Gusty winds are expected to be the most noticeable impact
  along the West Coast. West to northwest winds will increase
  today with gusts peaking around 20-30 mph along the northern
  Seward Peninsula coasts into the Kotzebue Sound. Winds will
  then dramatically increase with the arrival of the next system
  in the Bering with wind gusts ranging 25-45 mph possible along
  the Bering Sea Coast. Greatest gusts are expected to be along
  St Lawrence Island as the main system is expected to remain in
  the western Bering Sea.

- Any lingering showers along the Chukchi Sea Coast will
  gradually decrease throughout the day before widespread
  precipitation returns Wednesday. Rainfall totals are expected
  to be around 0.10-0.50 inches of rain with the highest impacts
  expected along the southern Seward Peninsula, Norton Sound
  Coast, and YK Delta. Rainfall is expected to be especially
  heavy across St Lawrence Island with locally higher totals up
  to an inch possible.

- Temperatures are expected to remain relatively steady with
  highs near 50 before cooling to the mid 40s Wednesday as the
  next system begins to impact the area. Overnight lows are
  generally expected to be in mid to upper 30s.

North Slope and Brooks Range...

- Cool and unsettled weather remains through midweek. Scattered
  to numerous showers are expected to continue beneath the
  lingering upper level trough. Rainfall will generally be
  0.10-0.50 inches through Monday with the highest totals
  expected further west. Snow levels around 1-2,000 feet will
  support snow in the Brooks Range, with total accumulations of
  a trace to 2 inches expected.

- Westerly winds increase Monday with gusts of 30 to 40 mph
  possible along the Arctic Coast west of Deadhorse and gusts of
  15 to 25 mph possible along the coast east of Deadhorse.

- Highs are expected to be the warmest today, gradually trending
  cooler through midweek with temperatures in the upper 40s to
  low 50s today dropping to the upper 30s to mid 40s by
  Wednesday. Overnight lows will generally be in the mid 30s
  with some areas in the western Arctic Plains falling below
  freezing into the upper 20s Tuesday night. Areas across the
  Brooks Range are expected to remain colder with lows in the
  low 20s.

- Expect showers through much of the week as additional
  disturbances continue to circulate around the lingering low
  pressure in the Arctic.

&&

.SHORT TERM...Today through Wednesday Night.
The current pattern is dominated by a broad upper trough over
northern Alaska, with a cold core low moving southeast from the
Chukchi Sea across the Interior. This system will keep
conditions cool, wet, and windy today as the low continues to
move southeast over the region. Precipitation will shift farther
southeast today, with the best coverage across areas of higher
terrain where orographic lift adds to the the large-scale
ascent. Cold air aloft will keep snow levels fairly low,
generally around 1,500-2,500 feet, so areas of higher terrain
may be of concern for accumulating snowfall. West to northwest
winds will increase behind the low as pressure rises over
western Alaska, with the strongest gusts along the Northwest
Coast and higher terrain across the Interior. As the low moves
farther southeast towards the panhandle this evening, the main
area of precipitation will shift along with it and become less
organized, but the larger trough will remain, keeping chances
for continued scattered showers.

The Alaska Range deserves particular attention today as the
combination of cooling aloft, persistent precipitation, and
terrain lift allows snow levels to fall to around 1,500-2,500
feet. This is low enough for accumulating snow along the higher
portions of the Richardson Highway in Isabel Pass, where 4 to 8
inches are expected with locally higher amounts above pass
level. Precipitation will initially be wet, but continued cold
advection and evaporative cooling should allow the snow level to
fall throughout the day rather than rise much with daytime
heating. Northerly to northwest flow into the range will also
maintain orographic lift even as the main surface low shifts
east, helping snow persist over the higher terrain throughout
the day.

The upper low over the panhandle will continue to weaken and
move farther south on Tuesday allowing the pressure gradient and
precipitation coverage to ease across much of northern Alaska.
The remaining trough will still support scattered showers,
especially across the Brooks Range and North Slope, but the
central and eastern Interior should see a noticeable decrease in
precipitation as subsidence increases behind the departing
system. Higher pressure building in from the North Pacific
should bring more breaks in the clouds and allow temperatures to
begin to recover. How much warming occurs will depend on how
quickly cloud cover breaks with some areas warming into the 50s,
while lingering clouds and showers will keep other areas
cooler. The developing ridge will also weaken the winds across
the Interior, however some gusts will linger near the West Coast
and exposed ridges in higher terrain. By Tuesday night,
attention will shift west as the next disturbance strengthens
over the western Bering Sea. Increasing height falls and
moisture transport ahead of that system should start rebuilding
the cloud and wind fields along the West Coast, bringing an end
to the brief improvement in conditions.

The western Bering system becomes the main feature on Wednesday
as the low strengthens and its associated frontal zone moves
toward western Alaska. Increasing moisture transport ahead of
the low should bring a return of more widespread rain to the
West Coast and western Interior, while tightening pressure
gradients bring stronger coastal winds. The central and eastern
Interior should remain relatively quiet as the front remains
west, but precipitation and wind impacts could spread farther
east if the Bering Sea low deepens more quickly or tracks
farther east than currently expected. A majority of the impacts
will fall mainly in the extended period which will be covered in
the extended forecast section.

&&

.LONG TERM...Thursday through next Monday.
The upper level pattern mid to late week across Northern Alaska
will be dominated by an H5 ridge in the Gulf of Alaska
extending north into Alaska and Northwest Canada, with a broad
H5 low and associated trough out over the Bering Sea and Western
Alaska. Up across the North Slope and High Arctic, an H5 low
centered over the Beaufort Sea Thursday will track east as upper
level ridging from Siberia and the Chukchi Sea shift east. With
this setup, southwesterly flow will help to push temperatures
warmer later in the week while allowing for several fronts to
work into Western Alaska with widespread rain and gusty winds.
The first front will be ejected from a triple point low in the
Bering Sea late Wednesday into Thursday into Western Alaska,
with rain and winds shifting across the Interior Thursday into
Friday.

This system will be tapping into atmospheric river moisture
from as far south as 20-30N, supporting moderate to heavy rain
across Western Alaska. The biggest difference amongst GFS/ECMWF
ensembles continued to be how far east this precipitation will
get, with the ECMWF favoring a more easterly track versus the
GFS more westerly track. Overall rainfall amounts Wednesday
through Friday have come into increasing agreement with the
latest guidance, showing around 0.5 to 1.5 inches across the
Central/Western Interior, Brooks Range, and Western Alaska.
Locally higher totals around 1.5 to 2.5 inches will be possible
across the West Coast, with highest totals expected out at St.
Lawrence Island given their closer proximity to the main fetch
of moisture. Driest conditions are expected across the Arctic
Coast/Plains and in the Upper Tanana Valley where southerly
downsloping flow will keep conditions drier. With colder
antecedent conditions out ahead of this large plume of moisture
lifting north towards the Brooks Range, expect a rain/snow mix
in this corridor with moderate snow accumulations possible
across highest elevations. Winds out of ahead of this first
front will pick up late Wednesday into Wednesday night, peaking
on Thursday, with strongest wind gusts across the West Coast
around 30 to 50 mph. Limited coastal impacts are expected with
these winds however, given the bulk of the strongest winds are
expected to be offshore.

Following that first round of widespread precipitation late
Wednesday into Thursday and Friday, persistent low pressure in
the Bering Sea will continue to send additional shortwaves and
surface lows into Southcentral and Western Alaska. This pattern
will keep precipitation chances around through the weekend into
early next week, as temperatures hold seasonable for early
September. During this timeframe, the overall trend shows the
bulk of ensemble guidance allowing for that broad area of low
pressure in the Bering Sea to shift east, with the main caveat
being just how quickly the ridge in the Gulf of Alaska will
weaken and shift east.

&&

.COASTAL HAZARD POTENTIAL...
A strong area of low pressure in the Western Bering Sea will
eject a front into Western Alaska late Wednesday into Thursday
with widespread moderate to heavy rain and gusty winds. While
wind gusts are expected to peak around 30 to 50 mph along the
West Coast, limited coastal impacts are expected at this time
given the bulk of strongest winds will be offshore. The only
exception to this will be around Hooper Bay where more southerly
flow is expected.

&&

.FIRE WEATHER...
Fire weather concerns remain low this week across the Interior.
As a low tracks southeast into the Gulf of Alaska later today
into tonight, scattered to widespread rain showers and high
elevation snow will continue across the Southern Interior and
Alaska Range. Additional rainfall totals through tonight will be
around 0.10-0.50" in this corridor, locally higher around Delta
Junction and the Alaska Range closer to 0.50-1.00". West to
northwest winds will increase later today across the Interior,
with gusts peaking around 25-35 mph, strongest in the
Middle/Upper Tanana Valley and across higher elevations, before
subsiding Tuesday morning. Conditions will trend drier Tuesday
and Wednesday as isolated showers persist, with attention
turning to late Thursday into Friday as another round of
widespread rain lifts northeast from the Bering Sea. Southwest
flow will lead to cooler temperatures early in the week trending
warmer, which with drier air, will lead to minimum RHs
Wednesday and Thursday dropping to around 35-45% for driest
locations out ahead of the next round of widespread rain. Winds
will be breezy on Wednesday with gusts to around 20 to 30 mph,
with gap winds through Alaska Range passes picking up Thursday
into Friday out of the south with gusts of around 30 to 45 mph.

&&

.HYDROLOGY...
As as low pressure system tracks southeast towards the Gulf of
Alaska today into tonight, rain and high elevation snow will
continue across the Southern Interior and Alaska Range.
Additional rainfall totals through tonight will be around
0.10-0.50" in this corridor, locally higher around Delta
Junctionand the Alaska Range closer to 0.50-1.00". Another low
is expected to bring more rain to the West Coast and Western
Interior Wednesday into Thursday, with rain building across the
Interior Thursday into Friday. Overall rainfall amounts
Wednesday through Friday have come into increasing agreement
with the latest guidance, showing around 0.5 to 1.5 inches
across the Central/Western Interior, Brooks Range, and Western
Alaska. Locally higher totals around 1.5 to 2.5 inches will be
possible across the West Coast.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory until 4 AM AKDT Tuesday for AKZ849-850.
MARINE...Small Craft Advisory from 1 PM to 4 PM AKDT this afternoon for
     PKZ811.
     Small Craft Advisory from 1 PM this afternoon to 4 AM AKDT
     Tuesday for PKZ812.
     Small Craft Advisory from 10 AM this morning to 10 PM AKDT
     this evening for PKZ857.
     Small Craft Advisory from 10 AM this morning to 4 AM AKDT
     Tuesday for PKZ858.
&&

$$

SYNOPSIS.......Cruz
KEY MESSAGES...Cruz
SHORT TERM.....Cruz
LONG TERM......MacKay
COASTAL........MacKay
FIRE WEATHER...MacKay
HYDROLOGY......MacKay