000
FXAK69 PAFG 122304
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
304 PM AKDT Wed Aug 12 2026

.SYNOPSIS...
A summer-like pattern will continue over most of Northern Alaska
as a ridge builds in from the south and stations itself over the
area through the weekend. On the west side of the ridge, scattered
showers and isolated storms will be prevalent through this
evening from McGrath northward to the Western North Slope. A weak
piece of energy from a low in the Pacific will race northward and
be the main driver of precipitation chances today. The Eastern
North Slope will remain dry due to a surface high north of
Kaktovik. Easterly winds along the Eastern Arctic Coast should
keep it cooler than the Plains and Chukchi Sea Coast. Otherwise,
the Central and Eastern Interior will be baking as highs remain in
the 70s/80s through the end of the week. There will be a chance
for isolated showers/thunderstorms, especially in the higher
terrain Thursday afternoon, but the most prominent time period
for some wet weather will be Friday as a weak upper level
disturbance provides moisture and enough lift to support showers
and thunderstorms across the Interior.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Warm and dry with highs in the 70s/80s today, tomorrow and
  Saturday. Friday will be a few degrees cooler, especially north
  of Fairbanks with an increase of clouds and scattered showers.

- From Fairbanks south/east it should remain mostly dry, but there
  will be a slight chance for a shower Friday morning into the
  afternoon as a weak disturbance moves overhead.

West Coast and Western Interior...
- Warm today with scattered showers and isolated storms, mainly in
  the Interior today as a weak disturbance moves from south to
  north.

- Temperatures are warm today with highs in the 60s to near 70
  along the coast, and in the mid to upper 70s inland. Tomorrow is
  a few degrees cooler due to an increase of clouds and showers
  but highs warm once again Friday through the weekend.

- After the showers/storms today and tomorrow, Friday through the
  weekend will be much drier with increased sunshine.

North Slope and Brooks Range..
- Warm weather is expected across the Central and Western North
  Slope with highs in the 60s along the coast, and mid 70s in the
  Plains. Cooler temperatures from Deadhorse east with highs in
  the 50s/60s. The Brooks Range will be in the 60s and 70s.

- Scattered showers and thunderstorms expected, particularly in
  the Western Brooks Range/North Slope today and tomorrow.

- Shower coverage shifts over the eastern North Slope on Friday
  with a chance for a thunderstorm in the Plains and Brooks Range
  with drier and warmer weather expected on Saturday.

&&

.SHORT TERM...
Although we are seeing an increase in ridging, there are quite a
bit of moving pieces to this forecast and each one will contribute
to different types of weather across Northern Alaska. Getting into
the details, we`ll look at the general overview of the upper
levels. We are beginning to see our overarching pattern take
shape over the Interior as a 594 decameter ridge near 30N extended
northward through the Arctic Coast. A relatively weak 560
decameter low south of the Alaska Peninsula near 45N is being
sheared apart allowing for a shortwave to extend northward in the
Western Interior today, then towards the Brooks Range/North Slope
tomorrow. Accompanied by this shortwave is a 300mb jet streak,
around 50-80kt which will help support some wet weather in Western
Alaska today and tomorrow, the Eastern Alaska on Friday as it
shifts east.

Otherwise, the main ridge of high pressure will be getting choked
in the middle by two areas of lower pressure on each end. This
allows for an anomalous +2 sigma high to set up over Northern
Alaska by Friday. The high will gradually meander northwest this
weekend, then potentially east by next week. But that will be
spoken about more in the long range forecast.

Getting into more of the specifics, there was a shortwave
mentioned before from a low in the Pacific. This wave of energy
will be coming with jet support and 700mb moisture. This energy
will be running into an atmosphere capable of producing
thunderstorms and will be the forcing mechanism. Isolated to
scattered showers and thunderstorms are likely to develop this
afternoon in the Western Interior, then gradually shift northward
to the Brooks Range this evening. The shortwave will lose some of
its punch as it slows and weakens over the Brooks Range tonight.
However, it will be over an unstable airmass, so thunderstorms are
still likely to occur north of the Yukon River with a bullseye
over the Northwestern Brooks Range and Western Arctic Plains
Thursday afternoon/evening. Moving into Friday, this energy will
be forced southeast by a weak cold front moving into the North
Slope, allowing for slightly cooler temperatures across the area.
With a degrading moisture source and less instability, a few
thunderstorms are possible in the Brooks Range, Central and
Eastern Interior Friday afternoon, but most of the area would only
see rain showers. This weekend, the ridge builds overhead with
very warm temperatures likely.

Getting into temperatures, something being monitored are the 850
mb temperatures which will be well above our normal values across
the area. For reference, the median 850 mb temperature for this
time of the year is around 5C. As this ridge builds in, we will be
seeing temperatures approximately between 10-12C across most of
Northern Alaska by Saturday. 850 mb temperatures this warm tend
to support surface temperatures in the 70s to low 80s for most
valley locations, disregarding cloud cover or any other
atmospheric features. Regarding cloud cover however, the ridge
will be pretty dry aloft, so there shouldn`t be too many clouds
except by any pop up shower or storm. So, there will be widespread
valley temperatures in the 70s and 80s, even on the North Slope
this weekend.

&&

.FIRE WEATHER...
Conditions will continue to warm today and tomorrow with many
valley locations expected to be in the 70s and low 80s, even in
the Arctic Plains. A shortwave will drift northward into an
unstable atmosphere over Western Alaska today through tomorrow
allowing for isolated to scattered thunderstorms from McGrath to
the Western Arctic Plain. the bulk of the activity will be north
of the Yukon River today, then in the Western Arctic Plain and
Brooks Range tomorrow. Isolated thunderstorms are then possible in
the Central/Eastern Interior on Friday. Temperatures will cool on
Friday, particularly on the North Slope with highs expected to be
5 to 10 degrees cooler, in the 60s and low 70s. Most of Interior
will also be approximately 3 to 5 degrees cooler due to an
increase in clouds and potential for showers and storms, but only
by a couple of degrees. The one exception will be in the Kuskokwim
Valley which remains in the upper 70s and low 80s while the
remainder of the Interior will be near the mid to upper 70s. This
weekend, the ridge builds in overhead allowing for a warming trend
over most of Northern Alaska.

Winds will remain fairly weak, but each afternoon there will be
variable diurnal wind gusts which may peak around 15 to 20 mph,
though they will be occasional and not widespread enough to
pinpoint exact locations. Min RHs will be low but mainly remain
above critical values with valley locations bottoming out near 30%
through the weekend. Isolated 25-30% values are possible in the
Tanana/Kuskokwim valleys, particularly this weekend. We will gain
more confidence in any critical values over the next couple of
days.

&&

.HYDROLOGY...
No concerns at this time.

&&

.LONG RANGE...
Throughout the extended period the stagnant high that has
remained persistent over Alaska will begin to progressively weaken
and be forced north and east by a closed low originating from the
Bering Sea that will travel towards the southwest coast of Alaska
on Sunday morning. Though there is low confidence, model guidance
suggests that by the end of the extended period, Alaska will be
divided by ridging along the Brooks Range and Interior and general
troughing towards southern portions of Alaska. Cooler
temperatures will likely be felt throughout the southwestern
portions of Alaska as soon as Monday when the state begins to be
divided between Northern ridging and southern troughing, with the
cooler conditions lasting through Tuesday. Generally drier
conditions will persist at the beginning of the extended period as
the ridge lingers through Saturday. As the Bering Sea low
approaches the southwest coast on Saturday wetter weather and
thunderstorm potential increases throughout the YK-Delta with
chances for scattered thunderstorms Saturday evening and isolated
storms in the Interior through Tuesday. Relatively calm winds are
expected throughout the extended time frame with the exception of
the Alaska Range Sunday to Tuesday, as the Bering Sea Low
increases the likelihood of both Isabel and Windy Pass
experiencing higher wind gusts throughout the end of this period,
although the peak strength and timing of these wind speeds are
still not certain.

Coastal Hazard Potential Days 3 and 4...None

&&


.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Heat Advisory for AKZ816.
     Heat Advisory for AKZ806-808.
PK...None.
&&

$$

SYNOPSIS...Bianco
KEY MESSAGES...Bianco
SHORT TERM...Bianco
LONG RANGE...Donner
FIRE WEATHER...Bianco