654
FXAK68 PAFC 121224
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
424 AM AKDT Sat Jul 12 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through
3/Today through Monday evening)...

A weak shortwave continues to slide south through the southern
Copper River Basin this morning. Light rain persists along the
Chugach, across Valdez, and into Prince William Sound. Farther
west, increased instability is lending to scattered showers over
the southern Talkeetnas southwest across parts of the Anchorage
Bowl and western Kenai Peninsula. Both areas of rain and showers
are expected to taper off through Saturday morning.

The forecast remains on track through the weekend, with quiet
weather expected overall. The upper low in the NE Gulf will exit
to Canada while an Arctic ridge builds southward across the
mainland to Southcentral. The ridge will cut-off as it moves
overhead of Southcentral Saturday night, then connect up with a
building ridge over the NE Pacific and shift eastward Sunday
through Monday. Model guidance is coming into better agreement
with a weak shortwave rounding the base of the ridge and moving
over the Kenai Peninsula for late Saturday with a second,
stronger wave for late Sunday into Monday lifting north across
the western Gulf and into Cook Inlet as the arctic ridge slides
to the southeast.

Given the latest model guidance, the forecast for the weekend
looks the same, with mostly dry conditions and partly to mostly
sunny skies for most of Southcentral. There will be enough
instability for some afternoon/evening convection, but with weak
storm motion, these will be confined primarily to higher terrain.
There is also potential for a push of low clouds up Cook Inlet as
the ridge shifts eastward by Sunday morning, so that could lead
to more clouds and cooler temperatures for some communities on
Sunday.

Forecast confidence drops significantly for Monday. There is
overall agreement with the large scale pattern and flow, with the
ridge exiting eastward and Kodiak/Gulf of AK/Southcentral all
coming under the influence of multiple upstream troughs and deep
southerly flow. Guidance varies on the track and strength of
individual short-waves and therefore on potential for rain. At a
minimum, expect a trend toward cooler and cloudier conditions.
None of the features look particularly strong, so also expect a
chance of rain - but likely light intensity and accumulation.

-SEB/TM

&&


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

The forecast generally remains on track; the most notable
overnight update was to increase wind speeds and adjust the timing
of rain as a front sweeps eastward across the Bering Sea on
Sunday and Monday. Otherwise, much of the previous forecast
discussion stands, with a few minor edits:

Conditions across Southwest Alaska and the Bering Sea are fairly
quiet owing to a collection of weak weather systems affecting the
area. Weak ridging over the Alaska mainland and light offshore
flow will lead to fairly warm temperatures, with high
temperatures in the upper 60s and into the 70s for Southwest
Alaska. Warm temperatures and weak shortwaves rotating around the
ridge will continue to produce scattered to numerous showers
across much of the region through the weekend. Temperatures reach
their peak today with interior areas seeing highs exceed 70
degrees as ridging builds in overhead. This will also contribute
to thunderstorm potential, with isolated storms developing
generally along an axis from the Western Alaska Range over the
Kilbuck and Ahklun Mountains, which through the evening hours
should migrate off the high terrain with potential to move into
Aniak, Bethel, and there is even a chance to reach parts of the
Kuskokwim Delta coast, particularly near and south of the mouth of
the river.

Out west, a weak surface low brings light rain and low stratus to
the Bering Sea and Aleutians. The low dips south of the Aleutian
Chain today, spreading precipitation as far as the eastern
Aleutians and southern Alaska Peninsula. Otherwise, a col over the
eastern Bering Sea leads to stagnant conditions with stratus and
fog. The upper component of the low weakens and elongates, pushing
back north on Sunday. This combines with an incoming front off a
Kamchatka low that returns southerly winds to the western Bering
Sea. A subtle shift to onshore flow also beings on Sunday for
Southwest Alaska, heralding cooler and more stable conditions.
This will increase fog and stratus potential along the coast, and
thunderstorms retreat inland, being limited to the Lower Kuskokwim
Valley and Western Alaska Range for Sunday afternoon/evening. By
Monday, the bulk of the front reaches the central Bering Sea and
the Pribilof Islands, though winds remain below gale force. A
broad shortwave trough lifts across Southwest Alaska, promoting
more widespread wetter conditions with numerous rain showers.

&&

.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)...

Low pressure in the northern Gulf of Alaska remains fairly
stationary through the end of next week though its exact placement
remains uncertain. The GFS places it off the coast of the Kenai
Peninsula with the Canadian and ECMWF both place it just east of
the Barren Islands. Therefore, confidence on the duration and
frequency of the waves of moisture and cloudy conditions each
model suggests into Southcentral is low. However, partly cloudy
skies are most likely in Southcentral away from the coast. High
pressure builds for the Copper Basin in the long range resulting
in a better chance of partly cloudy skies and dry conditions.

In the Bering, a low moves through the Northern Bering Sea during
most of the long range period. Additionally, high pressure
strengthens over the SW Mainland. Though timing and strength
differ with each model, consensus is that the front progresses
eastward toward the SW Mainland as the high builds over the
Mainland. Confidence remains low though in this solution because
of the non-model consensus. Widespread rain and cloudy skies will
accompany the front though regardless of its exact track.


&&


.AVIATION...

PANC...VFR conditions are expected to persist through the period.
Winds will generally be light and southerly through midday today,
then becoming westerly to southwesterly this afternoon. Showers
also look to develop this afternoon, but should remain mostly
confined to the mountains.

&&


$$