Butte, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

560
FXAK68 PAFC 160056
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
456 PM AKDT Sun Jun 15 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Tuesday)...

Relatively warm and dry weather is expected for interior
Southcentral AK for the remainder of this weekend and into the
start of the work week. Conversely, the Southcentral coastline to
see continued periods of light rain, drizzle, and mist with mostly
cloudy skies. Upper level systems have favored winds advancing up
Cook Inlet this morning, resulting in the return of this more
maritime airmass. As a result, cooler daytime temperatures today,
though abundant sunlight and dry air aloft should help dissipate
or shrink this cloud deck through the remainder of the evening.
There is the potential that this pattern repeats into Monday
morning, bringing another round of the marine stratus into the
Western Kenai Peninsula, Anchorage area, and Mat-Su Valleys. This
would similarly be expected to breakdown with the afternoon heat.

The weather pattern through early next week will remain mostly
consistent to the current pattern. Upper-level flow and the arrival
of more favorable convective patterns, including the entrance of
several shortwaves from the east. This creates a favorable pattern
for showers and thunderstorms with each passing trough. As such,
thunderstorm potential similarly is expected to rise early next
week, currently expected mostly for the Susitna Valley, the Copper
River Basin, with elevated thunderstorm initiation off of the
Talkeetna Mountains becoming increasingly likely given the quick
deterioration of mountain snowpack. However some locations closer to
bodies of water are expectedly remains relatively cooler.
Locations like Seward, Whittier, and Valdez to expect a relatively
consistent sea- breeze picking up during the afternoon hours,
given the strong diurnal heating trend. Additionally, over
interior Southcentral haze originating from Canadian wildfires
will become increasingly apparent. Strongest over the Copper River
Basin, the Mat-Su Valleys, and visible in Anchorage, this haze
will appear brownish and slightly reduce visibility along the
horizon.

-CL/Brown

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: This afternoon through Wednesday afternoon)...

The Bering Sea, Aleutian Islands, and coastal Southwest Alaska are
currently under the influence of two low pressure systems: one
near Saint Matthew Island in the Northern Bering Sea, and one
just south of the Alaska Peninsula in the North Pacific.
Meanwhile, high pressure is bringing clearer skies and warmer
temperatures to interior Southwest Alaska.

For the Bering Sea, Aleutian Islands, and Southwest coastline,
expect more active weather to persist through tomorrow afternoon,
especially around the Alaska Peninsula. Mariners can expect some
gales south of the Alaska Peninsula tonight, and the Pacific side
of the peninsula can expect moderate to heavy rain along the
front. The low weakens and exits south through Monday morning,
bringing a reprieve through mid-week. By Wednesday afternoon,
another North Pacific low begins to approach the Western and
Central Aleutians. Gale-force winds are possible, and the decent
moisture advection associated with this storm will likely bring
moderate to heavy rain for the Central Aleutians.

For Southwest Alaska, hot and drier conditions continue,
especially along Kuskokwim Valley. Temperatures will likely hit
their peak tomorrow afternoon, with highs of 70-79 degrees for
Kuskokwim Valley and highs of 60-69 degrees for most other parts
of Southwest Alaska. These warmer surface temperatures will create
a favorable environment for convection. Chances are high that
we`ll see some lightning by Tuesday over interior Southwest
Alaska, with the most likely location being Kuskokwim Valley, Lime
Village, and the northern reaches of Bristol Bay Borough.
However, the intensity and location of these thunderstorms
continues to be a bit challenging to forecast. Models have
generally been trending towards more organized upper level
shortwaves moving east to west across Southwest Alaska. This could
lead to greater cloud cover, making the environment less
conducive to thunderstorms than currently forecast. In addition,
the more organized upper level shortwaves could lead to the
development of a weak surface low near Bristol Bay, which could
advect in a more stable, maritime air mass that limits convection.
Given these trends, have cut back a bit on thunderstorm coverage
with this latest forecast. Stay tuned as we continue to refine the
forecast.

-Chen

&&


.LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)...

For much of the long term, the operational models agree that the
upper level ridge of high pressure that has been situated across
interior Southcentral will remain steady-state and anchored in
place, keeping temperatures generally warmer than average. The
ridging will also keep an upper level easterly to northeasterly
flow, allowing for more hazy skies from the Canadian wildfires,
particularly for the Copper River Basin. This flow regime will be
reinforced by a large upper level low across the Gulf of Alaska.
Afternoon and evening showers and thunderstorms will be likely
confined to the northern Susitna Valley and Copper River Basin.
There is also fair agreement at the end of the long term of a
large upper low in the Bering with smaller shortwaves rotating
around its periphery that may help nudge and erode the ridge
across Southcentral and force it to lift to the north. At the same
time, for the Aleutian chain, there is average confidence of a
large low pressure system moving out of the North Pacific and
across the islands and retrograding to the northwest with its
front becoming more elongated and pushing into the western Gulf of
Alaska.

-AM

&&


.AVIATION...

PANC...A stubborn marine layer crept into the airport Sunday
morning into the early afternoon and brought in IFR ceilings. This
marine layer will be the big forecast challenge for around the
airport again overnight tonight and into Monday morning as the
low-level flow will remain southwesterly up Cook Inlet and
continue to push any marine stratus toward Anchorage. While there
is a good chance that the low ceilings develop again tonight
shortly after midnight, the presence of an upper level wave
tomorrow and the increased vertical mixing due to that makes it
more likely to clear out the low clouds earlier on Monday than
what happened today. However, this marine layer and potential
periods of lower ceilings may come and go over the next few days.

&&


$$