197
FXAK69 PAFG 212249
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
249 PM AKDT Sun Jun 21 2026

.SYNOPSIS...
A rinse and repeat pattern continues through Monday ahead of an
unseasonably wet frontal system pivoting into the southeastern
interior on Tuesday. Thunderstorm chances across the southern
interior are the forecast challenge for Sunday and Monday, but they
are expected in the same general area as the past two days. A
frontal boundary pivoting from southeast to northwest focuses
thunderstorm chances on Tuesday and shifts them over the Western
Interior by Wednesday. Locally heavy rainfall is possible with
storms on Tuesday and rising river levels are possible.

&&

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

- Warm temperatures continue through Tuesday, with widespread highs
in the mid 70s to low 80s. The warmest temperatures continue to be
across the Yukon Flats where temperatures around 80F continue today
and Monday with warmer temps up to 85F on Tuesday.

- Scattered afternoon and evening thunderstorms are expected across
the Southern Interior Sunday through Tuesday with isolated
thunderstorms possible over the eastern Brooks Range this evening.

- A front tracking from east to west brings high rain chances from
the White Mountains southward late Monday night through Tuesday
night with locally heavy rain possible, especially near the Alaska
Range.

West Coast and Western Interior...

- Temperatures remain seasonably cool along the West Coast, with
temperatures in the 50s to 60s. In the Western Interior, highs in
the mid to upper 70s are expected to continue.

- Scattered thunderstorms are expected in the Upper Kuskokwim and
Lower Yukon Valleys Sunday afternoon and evening, with isolated
thunderstorms in the Middle Yukon Valley. Storm chances become more
isolated on Monday and continue through Wednesday afternoon.

North Slope and Brooks Range...

- Cooler conditions are expected today in the wake of yesterday`s
cold front with a warming trend starting on Tuesday.

- A frontal boundary brings rain chances to the central Arctic Coast
and widespread clouds Monday morning before clearing by Tuesday
morning.

- Northern Brooks Range valleys will see much cooler highs in the
50s or low 60s today, with temperatures quickly recovering into the
upper 60s or low 70s by Tuesday.

- Isolated thunderstorms will be possible over the Eastern Brooks
Range today with a lull Monday and Tuesday before storm chances
return on Wednesday.

&&

.FORECAST ANALYSIS AND DISCUSSION...
Upper ridging dominates the pattern across Interior Alaska between
Arctic troughing over the North Slope and a closed low centered near
Kodiak Island. The Arctic trough is sending a cool front southeast
across the interior that will limit the northwest extent of
thunderstorm chances while also focusing afternoon thunderstorm
development along its leading edge. A drier post-frontal air mass is
also resulting in deeper mixing and near Red Flag Warning criteria
conditions across the northern interior under crystal clear skies.
The pre-frontal airmass has temperatures warming through the 70s and
dew points in the 50s early this afternoon, which is already
initiating thunderstorms across high elevation portions of the
interior. This thunderstorm activity is expected to peak this
afternoon then gradually diminish this evening.

By Monday morning the frontal boundary will have settled across the
southern interior. However, the sensible weather affects will be
very similar to Sunday with another day of scattered afternoon
showers and thunderstorms across the southern interior. Upper level
ridging begins to shift northward on Tuesday as a potent easterly
wave tracks around the Gulf of Alaska low and over the southeast
interior. As a result, warmer temperatures shift back across the
northern/western interior and North Slope for the middle of the
week. The more impactful weather associated with this frontal
passage is the potential for heavy rainfall across the southern
interior, mainly on Tuesday. More information is contained in the
hydrology section below, but precipitable water values exceeding 1"
and EFI/SoT values support unseasonably heavy rainfall mainly across
the Alaska Range.

&&

.FIRE WEATHER...
We have already begun to see lightning developing along a cold front
from near Arctic Village southwest to near McGrath and ahead of the
front over the Fortymile Country. We are expecting thunderstorms to
continue throughout the Interior, Western Interior, and eastern
Brooks Range through this evening. Scattered thunderstorms bringing
frequent lightning prompted issuance of Red Flag Warnings Sunday and
Monday afternoon/evenings. Winds are expected to be generally light
except around thunderstorms where erratic gusts up to 40 mph are
possible. Widespread high temperatures in the 70s and 80s are
expected through Tuesday with cooler temperatures and higher RH on
Wednesday east of the frontal boundary. The Yukon Flats and Western
Interior are expected to stay dry with high temps around 80F and RH
values as low as 25%.

By Tuesday morning, rain showers and embedded thunderstorms
associated with a frontal system are expected to begin across the
southeast interior and spread west across the southern interior.
This frontal system is expected to bring a swath of wetting rains
across the southern interior. As the front passes, cloud cover, and
rainfall limits high temperatures and raises RH values. This front
is expected to stall roughly between McGrath and Bettles for
Wednesday into Thursday. This front brings potential for locally
heavy rainfall amounts >1", especially across the north-facing
slopes of the Alaska Range and the foothills.

&&

.HYDROLOGY...

As we progress into the week, a front will be moving westward over
the state. As this front progresses, we are expecting widespread
rain showers and thunderstorms. Rain showers and thunderstorms are
expected to begin Tuesday morning for the eastern Alaska Range and
spread west through Tuesday night when the time of heaviest rainfall
is forecast. Widespread rainfall totals of 0.5" to 1" and locally
higher amounts >2" possible will combine with glacial runoff to
result in rising mainstream river levels for the middle to end of
this week. Rapid rises of smaller rivers are possible with the
heaviest rain on Tuesday into Wednesday near the Alaska Range.

By Wednesday, this front will be set up over the Western Interior
and become relatively stationary, allowing for more precipitation to
fall through Thursday afternoon. Upwards of 1" or more is expected
in the Upper Kuskokwim area near McGrath and Lake Minchumina for
this event.

&&

.EXTENDED FORECAST DAYS 4-7...
A upper level low situated in the eastern Gulf of Alaska will bring
a series of shortwaves that move easterly across the state on
Thursday and Friday. These shortwaves will bring convective
preciptiation to the Central and Eastern Interior, with daily
chances for thunderstorms along higher terrain in the Central
Interior. Clouds and precipitation associated with these shortwaves
will not reach far into the Northern Interior, keeping warm
temperatures in the region. On Friday, a new upper level low moves
into the Bering north of the Aleutians. Though there isn`t consensus
on the strength and extent of this low, there is agreement that it
will bring troughing to at least the western portion of the state.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning for AKZ929-930-934>947-951>953.
     Red Flag Warning for AKZ935>945-947-951>953.
     Heat Advisory for AKZ833.
PK...Small Craft Advisory for PKZ812.
     Brisk Wind Advisory for PKZ813.
     Brisk Wind Advisory for PKZ859.
&&

$$

Kutta
Lewis - Hydrology and Fire
Schlezinger - Extended