417
FXAK69 PAFG 202307
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
307 PM AKDT Sun Sep 20 2026

.KEY MESSAGES...
Central and Eastern Interior...
- Periods of rain persist through Monday and diminish on
  Tuesday.

- The southern slopes of the AK Range likely see rain change to
  snow tonight or early Monday morning in Isabel Pass. Light snow
  continues at times through Tuesday. Snow accumulations around
  1 inch possible.

- Most precip ends Tuesday afternoon with some sun possible. Much
  drier with sunshine on Wednesday.

- Expect high temps in the 40s and low 50s today, more
  widespread 40s tomorrow through Wednesday. More widespread low
  temperatures below freezing Tuesday night onwards.

West Coast and Western Interior...
- Isolated light rain showers persist along the coast through
  Tuesday.

- A few rain/snow showers possible from the Kobuk Valley to
  Kotzebue Tuesday and Wednesday.

- Temperatures remain in the low to mid 40s for most of the
  region, gradually rising to the mid/upper 40s on Wednesday.

North Slope and Brooks Range...
- Light snow lingers along the Beaufort Sea Coast through
  Monday morning with about 1 inch of accumulation.

- Monday sees a drying trend for most of the area, but the
  Eastern Brooks Range may flurry or lightly snow again.

- An Arctic front brings more widespread light rain/snow to the
  Chukchi Sea Coast Tuesday and Wednesday.

- Light snow expected in the northern slopes of the Brooks Range
  Tuesday evening through Wednesday with rain to snow along the
  Beaufort Sea Coast Tuesday night into Wednesday. For parts of
  the Brooks Range, accumulations of 2-4" may be possible.

&&

.SYNOPSIS...
Fairly quiet weather for the first half of the upcoming week across
northern Alaska, although a complex pattern with weaker features
present will keep some possibilities of precipitation in the
forecast. Snow and rain shower chances remain across the North
Slope as weak arctic fronts rotate in keeping some chances of
minor snow accumulations, although drier conditions are possible
for the eastern north slope on Monday. Chances of showers
remain for parts of the central and eastern interior, along with
the West Coast through early next week before a drying trend
takes hold through Tuesday. Showers for the central and eastern
interior dwindle on Tuesday with drier weather arriving
Wednesday. A strong low will enter the Bering Sea the latter
half of the week.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/... A relatively quiet, or
at least less active pattern, will persist through the first
half of the upcoming week. Weaker shortwaves and remnant fronts
will keep chances of precip in the forecast, even as impacts
remain minimal at best.

Looking aloft, steering flow continues to be direct the larger
systems into south central and the Panhandle, as a deep trough
trough axis keeps the preferred storm track south of our area. N
to NW flow on the trough`s western flank will bring a steady
supply of snow and rain showers for the west coast through
Tuesday, as cold air over-running warmer maritime waters
generates ocean-effect convective activity. Am not expecting
anything significant in the way of accumulations however, with
less than in inch of new snowfall likely for areas near sea
level. Even then, anticipate most portions of the coast to
receive little more than a trace of snow. The North slope will
see weak arctic fronts pushing across through the week. With one
one currently moving through as of the time of writing, another
expected to move in the second half of Monday onwards, and
another slightly better developed shortwave arriving Tuesday.
These will bring in the potential for minor snow accumulations
along the North Slope at times, along with 2-5 inches through
the Western Brooks Range, including Howard Pass.

Looking further east across the central and eastern interior,
chances of showers remain through Tuesday as decaying frontal
remnants sent northward from a dying low in south central stall.
Am not expecting anything extraordinary in the way of precipitation
with these, and much of the rain that does fall will be spotty in
nature. By the latter half of Tuesday, these showers will be
diminishing, and more widespread drier weather will set in as a
ridge builds over the state. This building ridge will also pave the
way for colder temperatures to work their way into the rest of the
interior, with lows dropping below freezing through the first half
of the week. Wednesday will also feature a potentially strong low
entering the Bering Sea from the W, which looks likely to (at least
initially) stall as it interacts with both tropical moisture moving
up from the south and a potential second low to its west. While
ensemble guidance is not in good agreement on timing and placement
of the system, general confidence is building in the likelihood of
elevated seas for the Bering, with additional details for land-based
locations possible later in the week. For additional
information, refer to the long term discussion.


&&

.LONG TERM /WEDNESDAY THROUGH Saturday night... Looking towards
the extended period, the main feature of interest is going to
be a low moving into the Bering Sea Wednesday night into
Thursday. This low initially was looking to track a bit farther
north up along the West Coast, however now models are coming
into better agreement with the storm taking a more southerly
track towards Bristol Bay. As for the strength of this low,
models have been trending weaker over the past two days with an
upper level strength around 525 dam at 500 mb and around 970 mb
at the surface. As this low approaches Bristol Bay Thursday
night into Friday, strong gale force winds are expected along
the Yukon-Kuskokwim Delta coastline along with widespread
precipitation moving from south to north over Western Alaska.
Because this low is tapping into a good amount of tropical
moisture from the Pacific, temperatures are expected to
gradually warm up from west to east across the Interior going
into the weekend. The potential for some minor coastal concerns
such as high waters and high surf remains possible, but impacts
should be lower than with previous systems due to southeasterly
flow and less fetch. Going into the weekend, models are hinting
at this low partially splitting apart, with some energy moving
southeast into the Gulf of Alaska and the remaining energy
lingering just west of Bristol Bay. This solution would allow
for continued precipitation chances over Western Alaska through
the weekend with storm total rainfall amounts around 0.50"
regionwide. However, it is important to note that models start
to diverge when it comes to where the Bering Sea low moves once
it splits apart. Should the remaining energy move north towards
the Seward Peninsula, we could see higher chances for some minor
coastal concerns within Norton Sound as well as higher
precipitation totals closer to around 1.50" across Western
Alaska according to the NBM 75th percentile. As of right now,
forecast confidence is leaning towards the latter, but a more
northerly solution cannot be completely ruled out. We will
continue to monitor the development of this system over the next
few days.

As for the rest of Northern Alaska, weak upper level ridging will
sit over the Central/Eastern Interior, keeping conditions warmer and
fairly dry going into the weekend. As the low moves closer inland,
the pressure gradient tightens over the Alaska Range and supports
southerly gap winds through the passes. Model guidance is leaning
towards winds reaching Wind Advisory criteria (50/60 mph). We have
moderate confidence winds will strengthen beginning Thursday night
through Saturday morning, but exact wind speeds remain uncertain.
Otherwise, fairly benign weather across the Interior through the
weekend with a warming trend settling in due to southerly Chinook
flow over the Alaska Range. Along the North Slope, conditions will
remain cool and dry for the most part, with some rain/snow showers
moving north into the Western Brooks Range Friday into Saturday.


Coastal Hazard Potential... The aforementioned low in the Bering
does pose some coastal flooding threat. The main area we are
monitoring for this is the southern Seward Peninsula and Yukon Delta
Coast. There is still some uncertainty, but confidence is increasing
for a southern solution. With the low looking potentially
weaker, this would contribute towards fewer coastal impacts. In
particular, this would result in the predominant wind would be
south/southeast which could lead to some high water but nothing
too concerning. It is too early to give exact impacts but folks
along the coast should anticipate some higher than normal water
levels heading into the middle and end of next week. We will
continue to monitor the low as details on the track and strength
become clearer.


&&

.FIRE WEATHER...
Benign fire weather is expected. Scattered rain showers linger in
Fortymile Country through Tuesday morning, with an additional 0.10-
0.25" of precipitation. Snow levels drop over the course of Monday
night. Any showers could switch to non-accumulating snow above 1000-
2000 ft, with western Fortymile Country on the low end of the range.
Temperatures cool over the next few days, with highs in the low 50s
on Monday dropping into the low-to-mid 40s by Wednesday. There is
frost/freeze potential each night through at least midweek. Min RHs
stay in the 50-60% range and winds remain light and variable through
Wednesday.


&&

.HYDROLOGY...
Rivers and streams are starting to work their way down across the
Interior. The Chena River in particular has dropped back below minor
flood stage, although it still remains at or near bankfull.
Through most of next week, expect rivers and streams to continue
receding as passing showers produce significantly less
precipitation than the atmospheric rivers from the weeks prior.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
MARINE...Small Craft Advisory until 10 PM AKDT this evening for PKZ801-
     802.
     Small Craft Advisory from 7 PM to 10 PM AKDT this evening for
     PKZ850.
&&

$$

KEY MESSAGES...SPANN
SYNOPSIS.......SPANN
SHORT TERM.....SPANN
LONG TERM......SANTIAGO
COASTAL........SPANN
FIRE WEATHER...SCHLEZINGER
HYDROLOGY......SPANN