Butte, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

775
FXAK68 PAFC 190115
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
515 PM AKDT Wed Jun 18 2025

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

Discussion:

The large dome of high pressure that has been centered over inland
Alaska will begin to settle southwards as a large low drops south
across the Northwest Territories of Canada. Its front will help
nudge the upper ridge more over Southcentral as the low over the
eastern Gulf continues to drop south along the coast before moving
into the PacNW. This will allow for clearer skies and warmer
temperatures over much of Southcentral. The warmest temperatures
should be felt in the Copper River Basin where afternoon
temperatures will reach the upper 70s to low 80s the next several
days. The Mat-Su Valley and inland Kenai Peninsula will also see
temperatures warm nicely with highs in the mid to upper 70s by
Thursday. Coastal areas should see temperatures in the 60s,
especially for areas that remain mostly cloud free.

Convection will be mainly tied to the slopes of the Wrangells,
Talkeetna Mountains, and Alaska Range. Given lack of flow with high
pressure sitting overhead, storms will be pulse-like in nature
resulting in brief downpours, gusty outflow winds, and lightning.
Better instability axis will be over the Susitna Valley where
moisture advection will be a bit more enhanced under southerly mid-
level flow. Have kept the greatest shower and thunderstorm chances
north of Talkeetna and along the eastern slope of the Talkeetna
Mountains in the Copper River Basin. The thinking is that
convection will initiate over higher terrain, then rain itself out
as lack of flow will limit cells` ability to organize and be
longer-lived.

On Friday, a low over the Central Aleutians will lift a front up
into the western Gulf bringing rain and gusty gap winds to the AKPEN
and Kodiak Island by late Friday. The front will weaken as it
encounters the ridge and precipitation chances look to rapidly drop
off as the front washes out near the Barren Islands By Saturday
morning. Still, expect cloud cover to increase from west to east
as the front moves in, which will help stabilize the atmosphere
and limit convection to near the Wrangell Mountains by Saturday
afternoon.

- PP/KC

&&


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

Cool conditions have persisted across much of Southwest Alaska
today thanks to lingering cloud cover from the morning hours over
the Kuskokwim Delta and Greater Bristol Bay regions. Southwest
Alaska remains in a region of high pressure for the moment, wedged
between a weakening Bering low to the north, a deepening North
Pacific low moving into the Aleutians, and an area of low pressure
further east over the Gulf of Alaska. High pressure has resulted
in light and variable winds and mostly dry conditions. However,
moisture trapped beneath a warm air inversion has helped to
maintain cloud cover over much of the region. A lone area of light
rain has persisted within upslope flow into the windward side of
the Wood River Mountains.

Elsewhere, the Kuskokwim Delta has been the one dry spot with
mostly clear skies today, which has allowed the region to warm
into the mid 60s. Despite reduced thunderstorm chances, a lone
thunderstorm or two over the Kuskokwim Delta may still be possible
through the evening hours as satellite imagery shows evidence of
a few building cumulus cloud fields. A better chance for storms
may develop on Thursday with conditions forecast to be more clear
and warmer. Temperatures across the interior will likely breach 70
degrees. Additionally, the presence of a shortwave trough may be
enough to initiate storms along the Western Alaska Range and also
west of the Kilbuck Mountains into the Kuskokwim Delta.

Further west, an occluded low and front are lifting into the
Central Aleutians this evening with increasing rain and
northeasterly winds gusting from 15 to 25 knots. Adak is currently
reporting rain and this shower activity will expand eastward with
the front`s progression. Low pressure is forecast to deepen
somewhat tonight into Thursday, which will allow for a few
southeasterly gales along the front, though small craft winds will
be more prevalent. The front reaches the Alaska Peninsula
Thursday and Thursday night, eventually pushing into the Southwest
coast on Friday as a dying front.

BL

&&


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

There has been little overall change in the weather pattern
across the Alaskan zones. A broad upper level closed low and its
trough stretches across the Bering and extends a trough across
Southwest Alaska into the Gulf of Alaska through the forecast
period. The main low center meanders around the Central Bering. An
broad upper level ridge over most of Mainland Alaska reorients
with a high center forming across the Canadian border by midweek.
Individual models and ensembles remain is good agreement for the
large scale, for most of the forecast but begin to vary through
Wednesday. Greatest uncertainty rest with the smaller transient
details throughout the forecast.

Most of the Southern Interior will see scattered convection with
warmer temperatures South of the Alaska Range. Transient surface
lows and their fronts bring locally moderate rains across the
Central and Eastern Aleutians and Bering into Southwest Alaska,
the AKPEN and Kodiak Island by Tuesday. Frontal weather will
linger over Kodiak Island and the Southcentral coasts through
Wednesday. A second low and front starts another round of moderate
rain over the Western Aleutians and Bering late Sunday before
dissipating over the Central Aleutians on Tuesday. Another low and
front approaches the Western Aleutians on Wednesday.

- Kutz

&&


.AVIATION...

PANC...MVFR ceilings in place earlier this morning will continue
to clear out this afternoon. A light west to northwest sea breeze
will continue to affect the terminal through this evening, but it
will likely stay under 10 kts.

&&


$$