268
FXAK69 PAFG 131355
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
555 AM AKDT Thu Aug 13 2026

.SYNOPSIS...
A warm, dry pattern will persist across Northern Alaska through
the weekend as a strong ridge sits entrenched over the state. A
shortwave disturbance shifting northward Thursday will produce
showers and isolated thunderstorms north of the Yukon River,
peaking over the western Brooks Range and Arctic Plains Thursday
afternoon and evening. A weak disturbance pushing into the North
Slope will nudge this energy southeastward, bringing showers and
isolated thunderstorms, along with a brief dip in temperatures to
higher terrain and areas from Fairbanks north. High pressure
rebuilds over the region on Saturday, returning warm and dry
conditions through the weekend, with widespread temperatures
reaching into the 70s and 80s across valley locations. Along the
Arctic Coast, easterly flow will keep temperatures relatively
cooler in the 40s and 50s while ushering in areas of morning fog.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- A warm and largely dry pattern persists into the weekend, with
  high temperatures reaching into the 70s and mid 80s. As clouds
  and chances of scattered showers increase north of Fairbanks on
  Friday, temperatures will cool by a few degrees.

- A weak upper-level disturbance moving through on Friday will
  bring chances of showers and isolated thunderstorms, mainly from
  Fairbanks northward and across higher terrain. Any rainfall
  will be light, with drier weather returning Saturday as high
  pressure builds over the region.

West Coast and Western Interior...
- Warm conditions will continue through Thursday. Daytime highs
  will reach the 60s to near 70 along the coast, while inland
  areas warm into the mid to upper 70s.

- Showers and isolated thunderstorms will persist Thursday before
  tapering off, leading to a warmer and drier trend Friday through
  the weekend.

North Slope and Brooks Range...
- Warm weather will continue across the Western and Central North
  Slope and Brooks Range, with highs reaching the 60s and 70s.
  Highs will approach 80 across the Arctic Plains near Umiat.
  Temperatures will remain cooler from Deadhorse east along the
  Arctic Coast, with highs in the 40s and 50s.

- Scattered showers and thunderstorms are anticipated along the
  Western Brooks Range and North Slope through Thursday before
  shifting into the Eastern North Slope on Friday.

- Thursday morning, onshore flow will usher in fog along the
  Arctic Coast.

&&

.SHORT TERM...
An anomalously warm pattern will dominate Northern Alaska through
the end of the week as a 594 decameter ridge near 30N extends
northward to the Arctic Coast. A shortwave originating from a weak
560 decameter low south of the Alaska Peninsula will drift toward
the Brooks Range and North Slope Thursday. Accompanied by 50 to 80
knot flow within a 300 mb jet streak, this wave will act as the
primary dynamic forcing mechanism across Western Alaska and the
Northern Interior through Thursday evening. By Friday, the
overarching ridge gets pinched between low pressure features on
its flanks, allowing an anomalous high to set up over Northern
Alaska. Model guidance shows good agreement on this blocky pattern
remaining fairly stationary this weekend, with the primary ridge
remaining entrenched over Eastern Alaska and the Yukon.

As the shortwave interacts with an unstable airmass on Thursday,
it will draw on 700 mb moisture and jet support to trigger showers
and isolated thunderstorms north of the Yukon River, with a
bullseye over the western Brooks Range and Arctic Plains Thursday
afternoon/evening. On Friday, a weak cold front pushing into the
North Slope will force this shortwave energy to the southeast.
With a degrading moisture source and weaker instability, activity
over the Central and Eastern Interior and Brooks Range Friday
afternoon will transition primarily to showers with only isolated
thunderstorms possible.

Thermodynamically, 850 mb temperatures across Northern Alaska will
climb above normal values as the ridge builds overhead. Median 850
mb values for mid-August are around 5C, but guidance projects
widespread values reaching 10C to 12C by Saturday. With a
predominantly dry airmass aloft limiting cloud cover outside of
areas of convection, these elevated 850 mb temperatures will
readily support temperatures in the 70s and 80s across valley
locations, extending all the way to the Arctic Plains. Friday will
see a brief reprieve with temperatures a few degrees cooler,
particularly north of Fairbanks and across the North Slope, due to
an increase in clouds and a frontal passage before heating
resumes over the weekend.

&&

.FIRE WEATHER...
Hot and dry conditions persist across most of Northern Alaska this
week and into the weekend as upper level ridging continues over the
state. Embedded within the overall pattern is a shortwave feature
that will follow along the periphery of the upper level ridge,
causing isolated to scattered showers and thunderstorms across the
region into the weekend. For this afternoon, the highest chances for
thunderstorms will be from the lower Koyukuk Valley north towards
the Western Arctic Plains, with coverage shifting south and east
Friday afternoon. Due to the fairly disorganized shortwave feature
and increasing instability over the Central/Eastern Interior going
into the weekend, a broad area of isolated thunderstorms is expected
Friday afternoon from the Central Arctic Plains south through the
the White Mountains and towards the Upper Kuskokwim Valley. There`s
a non-zero chance for dry lightning to develop, mainly over the
Eastern Interior, but still looks to be unlikely for now. Continued
shower and thunderstorm activity is likely through the weekend as
the ridge gradually breaks down and interacts with an approaching
low pressure system in Bristol Bay.

Otherwise, widespread afternoon highs in the upper 70s/low 80s are
expected throughout the Interior and Arctic Plains. A Heat Advisory
is in effect beginning this afternoon through the evening for
temperatures nearing 80F in the Arctic Plains. Along the West Coast
and Arctic Coast, highs will be a tad bit cooler in the mid to upper
60s. Brief periods of cooler temperatures are possible Friday
afternoon where isolated to scattered showers occur. However, with
high pressure expected to continue this weekend, additional Heat
Advisories may be issued as clear skies, light winds, and limited
precipitation give way to temperatures nearing 85F, especially in
the Upper Tanana Valley and Yukon Flats. In addition to anomalously
warm temperatures, min RH values will remain fairly low between 30-
40%, with brief improvement across the Central/Eastern Interior
Friday afternoon due to increased chances for showers. For the Upper
Tanana Valley, isolated pockets of min RH values ranging from 25-30%
are possible this weekend, but will mainly stay above critical
thresholds through the weekend.

Looking towards next week, models are hinting at a chance for
southerly flow to set up over the state sometime Monday afternoon,
which may allow for some gusty winds to develop through the Alaska
Range Passes. If this situation plays out, we may see an elevated
fire weather risk north of the Alaska Range early next week. The
other possibility is that broad southwesterly flow sets up over the
state, increasing chances for cooler and wetter weather next week,
especially over Western Alaska. Given the high amount of forecast
uncertainty regarding this pattern, we will be keeping an eye on
this over the next few days. Overall though, winds will remain
fairly light going into the weekend. Some diurnally driven wind
gusts around 15 to 20 mph are possible, but should be occasional and
not widespread enough to pinpoint exact locations. Lastly, areas of
smoke and haze are expected to persist over the next few days as hot
and dry conditions continue across the Tanana Valley.

&&

.HYDROLOGY...
No concerns at this time.

&&

.LONG RANGE...

Throughout the extended period, model guidance diverges with two
main possible patterns. For the first regime, the persistent ridge
over Alaska will gradually weaken and be nudged north and east as
a closed low pressure system advances from the Bering Sea toward
the southwest coast on Sunday. Model guidance shows good overall
agreement on maintaining a blocky pattern, with upper ridging
remaining entrenched over eastern Alaska and the Yukon, while a
broad trough dominates the southern Bering Sea and northeast
Pacific. As this southern Bering Sea low approaches, deep moisture
with a tropical origin will spread across southwest Alaska,
increasing rainfall potential along the coast and introducing
chances for scattered thunderstorms across the Yukon-Kuskokwim
Delta on Saturday evening, with isolated convection continuing
into the Interior through Tuesday. Temperatures will begin to cool
across southwestern portions of the state by Sunday and Monday as
Alaska becomes split between northern ridging and southern
troughing, though highs in the 70s and 80s will persist under the
ridge across the Eastern Interior.

The second, less-likely solution favors warmer and drier
conditions with southerly flow from the Gulf of Alaska Monday
afternoon. As the Bering Sea low tightens pressure gradients
against the ridge, wind gusts could increase through favored
mountain passes of the Alaska Range, including Isabel Pass and
Windy Pass, from Sunday into Tuesday.

Coastal Hazard Potential Days 3 and 4...None

&&


.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Heat Advisory for AKZ806-808.
PK...None.
&&

$$

SYNOPSIS...Satcher
KEY MESSAGES...Satcher
SHORT TERM...Satcher
FIRE WEATHER...Santiago
LONG RANGE...Satcher