434
FXAK69 PAFG 311240
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
440 AM AKDT Fri Jul 31 2026

.SYNOPSIS...
Ridging is building over the Interior with warming temperatures
likely today. Over the weekend, temperatures will begin to
decrease over Western Alaska due to increased cloud cover, but
they remain warm in the Central/Eastern Interior and North Slope.
Temperatures will continue to fluctuate on Sunday, but they
should be cooler for most spots besides the Eastern Interior. More
uncertainty arises early next week as our attention turns to a
developing weak low in the Bering Sea. This low has the potential
to bring heavy rain and gusty west-southwest winds to Western
Alaska from Sunday night through at least Monday. The placement of
this low will help determine if the heaviest rain reaches as far
north as the Brooks Range, or stays south towards the Yukon River.
High Wind Watches have also been issued for the AK Range Passes
and Delta Junction from Sunday night through Tuesday evening. This
evolving pattern will be elaborated on in the Short Term Forecast
Discussion below.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Saturday is the pick of the weekend with mix sun and clouds and
  highs in the 70s to near 80. Temperatures remain warm on
  Sunday, but the Central Interior drops a few degrees. 60s to low
  70s are expected from west to east on Monday with Fairbanks
  around 70.

- Showers become possible Sunday afternoon from FNSB north and
  west with the highest probabilities expected from Minchumina to
  Bettles.

- The Southern AK Range, including Cantwell, likely sees steadier
  rain Sunday night into Monday.

- High Wind Watches have been issued for the AK Range Passes and
  Delta Junction from Sunday night through Tuesday night for
  southerly wind gusts up to 70 mph. There is some uncertainty
  and winds may end up being weaker.

West Coast and Western Interior...
- For those with outdoor activities planned, today and tomorrow
  are your days to do them as temperatures sit in in the 50s/60s
  along the coast and 70s in the Interior.

- Sunday features cooler temperatures and heavy rain moving in
  from the west as early as Sunday morning in St. Lawrence Island,
  and Sunday evening in the Interior. Moderate rain is likely
  north of the Seward Pen./Yukon River Sunday night as well.

- Periods of rain, heavy at times persist into Monday with
  widespread rainfall amounts around 0.50" to 1.50" possible.

- Winds gusts up to 45 mph along the West Coast and 35 mph in the
  Interior Valleys are possible on Monday.

North Slope and Brooks Range..
- Warm weather is expected with highs in the 50s/60s along the
  coast and 60s/70s in the Brooks Range and Flats through Monday.
  The coast will have periods of dense fog through Saturday.

- Mostly dry weather is expected today but rain showers exist in
  the Western Brooks Range and Chukchi Sea Coast today. Scattered
  showers are likely for most of the area Saturday afternoon, then
  the eastern half of the Slope into Sunday.

- Steadier rain moves into the Brooks Range from the south on
  Monday. Rainfall totals Friday-Sunday will be around 0.05" to
  0.15", heavier in the Western Brooks Range. Around 0.15" to
  0.35" possible on Monday in the Brooks Range.

&&

.SHORT TERM...
Satellite imagery from this morning shows the remnants of a frontal
system moving SE from the Upper Tanana. This is providing a shallow
cloud layer across the White Mountains and portions of the Eastern
Interior. These are not expected to last long as higher pressure
builds in from ridging expected to continue shifting east across the
state. This will allow for seasonal temperatures to return across
the Interior during the weekend with highs in the mid 70s to low
80s. Meanwhile, a series of shortwaves will continue to move NE
across the NW Arctic Coastline; providing ongoing isolated showers
across the West Coast through the start of the weekend. These
shortwaves are a part of a sub-arctic jet energy over Siberia that
is expected to shift south a play a larger role in the second half
of the forecast period.

Up to this point in the forecast, models are in fairly good
agreement. However this does not last much longer. The sub-tropical
jet is expected to move across the Kamchatka Peninsula by the mid
weekend and phase with the energy from the south moving sub-polar
jet. The timing and positioning of the phasing is the disagreement
that begins to be seen amongst the models. The GFS shows a more
aggressive solution, phasing just east of the Kamchatka
Peninsula. This would allow the trough to develop into a more
organized upper- level low as it moves into the Bering. Associated
with this system is a 990mb low and a series of fronts moving NE
across the state from the YK Delta. Widespread, heavy rainfall and
gusty winds are expected across much of the West Coast and
Western Interior Sunday and Monday. The earlier phasing would
allow higher potential for the system to tap into tropical
moisture from systems in the Western Pacific and allow for more
rainfall across the area. The ECMWF shows the phasing occuring
about 12 hours later and slightly farther east. This solution
would not allow the organized low to form until the trough reaches
the Central Bering and the warm front begins to move across the
YK-Delta. While this would still allow for widespread rain, the
heavier rainfall would be kept farther south over the Kuskokwim
Valley and South-Central Alaska. In addition, wind gusts would be
slightly weaker as the associated 925mb low-level jet will not be
as strong.

More uncertainty continues through the end of the forecast period.
The different solutions yield different impacts regarding the
strength and the positioning of the ridging that is expected to form
over Eastern Alaska out ahead of the trough. This will continue to
be monitored closely as southerly flow is expected to set up across
the central portion of the state; bringing gap winds across the
Alaska Range and chinooking conditions across the Interior. More on
this in the extended portion of the discussion.

&&

.FIRE WEATHER...
Drier weather has settled across much of northern Alaska as a
ridge build across the interior of the state. High Temperatures
through the weekend will be on a warming trend as the ridge
traverses east across Alaska, reaching into the 70s and -for some
locations-the lower 80s. Relative humidity will reach down to 25
to 35 percent over the weekend across the Eastern Interior and
Yukon Flats, and 30-50% across the central and Western Interior.
By late Sunday, widespread wetting rains will be spreading across
the Western Interior, and into the central interior by Monday,
though drier weather may linger further east between the Yukon
Flats and Fortymile country. Cooler temperatures in the 50s and
60s will arrive with this precipitation, with wet weather expected
to continue south of the Brooks Range through the first half of
the week.

&&

.HYDROLOGY...
An atmospheric river arriving across the western interior late
Sunday into Monday will bring river rises across smaller rivers in
the west and along the Alaska Range through the first half of next
week. No flooding concerns are expected. Precipitation totals of 1-3
inches are looking increasingly likely from Sunday to Tuesday for
these areas, with isolated higher amounts possible in areas of
terrain.

&&

.EXTENDED FORECAST DAYS 4-7...
The big story for the middle and latter half of next week will be
the decaying low along the west Alaska Coast. By Tuesday, the low
will have largely occluded. While the GEFS and EMCWF ensembles do
show some differences in final placement - dependent on how the low
phases with shortwaves moving in from the West and how strong a
ridge that builds to the east is - the broad brush strokes remain
the same. The low will remain centered over the West Coast until
late in the week when it is dislodged into the interior of the
state. By Tuesday, the heaviest precipitation over northern Alaska
will be winding down as the atmospheric river wraps around further
south, instead focusing on the Alaska Peninsula and areas further
east (Anchorage). The previously moderate to heavy rainfall over the
western interior will revert back to more standard periods of light
rain. In the east, drier weather (or at least a significantly lower
chance of showers) will prevail north of the eastern AK range as
southerly flow brings general downsloping across the area. The
southerly flow will also bring chinook conditions at times to some
of the mountain passes, with the strongest Chinook winds
likely to be Tuesday into early Wednesday.

Coastal Hazard Potential Days 3 and 4...
Some minor beach erosion and high surf are possible for Norton
Sound and the Kuskokwim Delta Monday and Tuesday as a 985-995 mb
low over St Lawrence Island sends SW winds up across much of the
west coast. More updates will be made available as forecast
confidence in a final track and strength of the low develops.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...High Wind Watch for AKZ837-847-849.
PK...Small Craft Advisory for PKZ811.
     Small Craft Advisory for PKZ812.
     Small Craft Advisory for PKZ856.
     Small Craft Advisory for PKZ857-858.
&&

$$

SYNOPSIS.......Bianco
KEY MESSAGES...Bianco
SHORT TERM.....Twombly
FIRE WEATHER...Spann
HYDROLOGY......Spann
LONG TERM......Spann
COASTAL........Spann