653
FXAK69 PAFG 072231
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
231 PM AKDT Mon Jul 7 2025

.SYNOPSIS...Ridge break down continued across Northern Alaska
today (Monday) as an Arctic trough interacts with a closed low over
the Gulf of Alaska. An associated arctic cold front began tracking
southeast across the state today and triggered several dozen
lightning strikes across the North Slope with blustery northwest
winds and cooler temperatures behind the front. Hot and dry weather
continued fire activity across the northern interior on Monday where
the ridge axis has held on the longed, but today is the last day of
temperatures reaching into the 80s for the foreseeable future. A
Red Flag Warning was expanded eastward across the northern
interior for Monday afternoon and evening for scattered to
numerous thunderstorms containing frequent lightning amidst dry
fuels. By Tuesday, temperatures cool to near or below seasonal
normal nearly everywhere and clouds become widespread except for
the west coast. Scattered rain showers are expected in the
vicinity of the front on Tuesday with a few afternoon
thunderstorms and more widespread rain chances on Wednesday as a
secondary disturbance tracks along the front. Rainfall amounts of
0.5"-1.0" are expected to be widespread across the east-central
interior by Thursday morning. Heavier amounts of 1.0"-1.5" are
expected across the southern Interior with localized amounts up to
2.0" where showers and thunderstorms are most persistent. Heavier
amounts are also possible northeast of Arctic Village where snow
mixes in on Tuesday with a few inches of accumulation by Wednesday
evening at elevations above 2500ft.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- The Red Flag Warning was expanded across the north-central
  interior for today due to numerous thunderstorms capable of
  frequent lightning and gusty winds that may start new fires
  and/or spread existing fires.

- A secondary disturbance embedded within deep WSW flow a band of
more stratiform rain roughly between McGrath and Circle on Wednesday.

- High temperatures cool each day through Wednesday as a cooler air
mass, increasing cloudiness, and rain chances spread across the
interior bringing welcome relief from the heat.

- Very comfortable weather expected late this week through the
weekend with highs around 70F and lows around 50F and little if any
rain expected.

West Coast and Western Interior...
- Warm and seasonably humid have a few thunderstorms along a
convergent boundary along the Middle Yukon and Koyukuk Valleys and
thunderstorm activity is expected to increase in coverage and
intensity this afternoon and evening as the cold front approaches.

- A Red Flag Warning is in effect through 10 PM for the Koyukuk
Valley where thunderstorms with frequent lightning and gusty winds
that may start new fires or spread fire activity.

- Dry weather continues for the West Coast and most of the western
interior behind the cold front with gusty north-northwest winds
gradually diminishing through the week.

North Slope and Brooks Range...
- Low stratus and areas of primarily `nocturnal` fog continue along
the Arctic Coast through much of the week, but breaks are more
likely near and east of Nuiqsut.

- A few thunderstorms are occurring along the cold front near
Deadhorse as of 1230 AKDT with more intense activity developing over
the eastern Brooks Range ahead of the front.

- Colder weather is expected on Tuesday and Wednesday with a rain
snow mix over the eastern Brooks Range on Tuesday then spreading
west on Tuesday night and Wednesday including a chance for minor
snow accumulation at Atigun Pass.

&&

.FORECAST ANALYSIS AND DISCUSSION...
An active period of weather unfolds over the next ~3 days as a
seasonably strong arctic trough digs south across Northern Alaska.
Two closed lows over the Gulf of Alaska interact with this trough
resulting in distinct waves of precipitation. Moisture wrapping
around a 548 dm Gulf low boosts instability ahead of the Arctic cold
front. The first wave of rain chances is therefore expected to be
more convective in nature with showers and thunderstorms primarily
developing along and ahead of the cold front. CAPE values around
1500 J/kg indicate plenty of energy for lightning, especially when
combined with strong forcing from the approaching frontal boundary.
Fortunately, environmental shear is generally 15 kts or less so
severe thunderstorms are unlikely. This outflow-enhanced cold front
surges southeast tonight then becomes quasi-stationary roughly
between McGrath and Circle on Tuesday as flow becomes more parallel
to the frontal axis. Frontogenesis increases between a second and
more energetic Arctic trough and a 545 dm closed low crossing the
Alaska Peninsula on Wednesday. Frontogenic events such as this one
can result in a narrow band of heavy precipitation with much lighter
amounts elsewhere. The latest ensemble means seem to be in good
agreement that this band of rainfall sets up between McGrath and
Circle and drops 0.5-0.75" of rainfall Wednesday through Wednesday
night with rainfall diminishing on Thursday. EFI guidance does a
good job of highlighting the areas of heavier rainfall with both
waves of precipitation and also picks up on the unseasonable and
likely non-impactful, high-elevation snowfall potential in the
Brooks Range Tuesday-Wednesday.

&&

.FIRE WEATHER...
Reduced winds will occur today for much of the Interior but it will
still be hot and dry. The exception is along the Alaskan Range up
into the central Tanana River valley where gusty south-southwest
winds are blowing today. Smoke will restrict visibilities until the
lower atmosphere mixes out later this morning. Widely scattered
thunderstorms return to the forecast today for the Nulato Hills
east to the White Mountains and east to the Yukon Uplands. More
numerous storms are expected Monday with a better chance for
wetting rains.

The big change this week will be from an unseasonably cool system
that will cold front that will drop down from the Arctic Monday
night and Tuesday. Widespread rain...cooler temperatures and
higher humidities should begin to help wildfire fighting efforts.
There will be strong west-northwest winds as that front drops down
through the central and eastern Interior on Tuesday. The wind and
rain should help to improve the smoky conditions.

&&

.HYDROLOGY...No concerns at this time.

&&

.EXTENDED FORECAST DAYS 4-7...
A warming and drying trend is expected during the extended period as
widespread below normal temperatures transition to above normal
beneath a building ridge and increasingly sunny skies this weekend.
The North Slope will be slowest to warm up, but warm southerly
downslope flow appears like to spread west to east early next week.
Primarily dry weather is expected across northern Alaska through the
extended, but a sneaky northwest flow shortwave may result in rain
chances near the Canadian border this weekend ahead of a building
ridge. A more amplified southerly regime is possible at the end of
the extended as the progressive ridging shifts east into Canada.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning for AKZ911-912-919-928-931>933.
PK...Small Craft Advisory for PKZ805.
     Small Craft Advisory for PKZ806-854.
     Small Craft Advisory for PKZ807-810-856.
     Small Craft Advisory for PKZ808-809-811-855.
     Small Craft Advisory for PKZ853.
     Small Craft Advisory for PKZ857.
&&

$$
Kutta