073
FXAK68 PAFC 061238
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
438 AM AKDT Sat Sep 6 2025

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

The forecast remains on track with rain returning today and
tonight as a large Bering Sea low extends a front into southern
mainland Alaska. The leading shortwave trough may be just enough
to promote some light rain showers for the Anchorage and Matanuska
Valley this morning as mid-level moisture begins to stream in
with southwesterly flow. Low-level flow begins to intensify out of
the south to southeast later today, leading to some downsloping
which limits precipitation amounts in the lee of the coastal
mountain ranges. A coastal ridge also develops as the front slowly
pushes into the western Gulf. This will initiate typical
southeasterly gap winds, including the Turnagain Arm, Knik River,
and Copper River winds later this afternoon. Expect light,
intermittent rain for inland locations, while 1 to 2 inches of
rain is squeezed out along the north Gulf coast through Monday.

As the main surface front lifts across Southcentral on Sunday,
weakening cross-barrier flow may limit downsloping and allow for a
more sustained period of light rainfall for inland areas. Upper
level support for the Bering low weakens as it progresses toward
Southcentral. The surface low opens into a trough Sunday night
through Monday. Thus, the potential for light rain showers will
persist area-wide. Decreasing pressure in the Gulf of Alaska
erodes the coastal ridge, however, leading to fairly calm winds
for the beginning of next week.

Quesada/Rux

&&



.SHORT TERM FORECAST SOUTHWEST ALASKA / BERING SEA / ALEUTIANS
(Today through Tuesday Morning)...

The forecast remains on track at least in the near term through
today. More about lingering uncertainty with a North Pacific low
below...Starting with the current weather status, a large
vertically stacked low continues to take up real estate in the
central Bering Sea this morning west of the Pribilof Islands. The
front it currently draped over mainland Southwest Alaska with
strong gusty southeasterly winds across the Kuskokwim Delta coast.
Along with the gusty southeasterly winds, higher wave heights and
increased water levels are likely this morning along the northern
Kuskokwim Bay coast including the communities of Kongiganak,
Kwigillingok, and Kipnuk. Peak water levels (1 to 2 feet above the
normal highest tide line) are expected late this morning before
slowly subsiding during the afternoon hours. While significant
coastal flooding is not expected, low-lying areas filling up with
water is not out of the question. Wave heights of 4 to 8 feet
within the coastal waters of the Kuskokwim Delta and along the
coast will persist most of today before slowly subsiding tonight
into Sunday morning. A Special Weather Statement remains out for
the Kuskokwim Delta Coast/Northern Kuskokwim Bay Coast to bring
further awareness to the water level rise, gusty southeast winds,
elevated wave heights/surf, and impacts.

Elsewhere, showery conditions will continue across the Aleutians,
Alaska Peninsula (AKPEN), and mainland Southwest for most of
today. While the Western and Central Aleutians will see improving
conditions as the day progresses due to a ridge building across
the western Bering, mainland Southwest and the AKPEN remain
showery through Monday. The Eastern Aleutians sees improvement by
Sunday afternoon as the ridge across the Western and Central
Aleutians moves east over the area.

Behind the developing ridge, a North Pacific low looks to track
in close proximity to the Aleutian Chain Sunday evening through
Tuesday morning. There is still uncertainty in exactly how close
the low will track to the Chain. As of early this morning,
guidance has come in stronger and shifted the track of the low a
little bit further to the north and closer to the Aleutians, which
would be a windier and rainier solution as opposed to a further
south in the North Pacific/away from the Chain solution. However,
guidance has been flipping back in forth between close the
Aleutians and further away; thus the continued uncertainty.
Continue to follow the latest forecast updates as details about
this system become more clear with time.

&&

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

Only minor changes from previous discussion... At the beginning
of the week, a gale or potentially storm-force low is likely to be
located near the central Aleutians. To the east, a trough extends
south across Western Alaska into the Gulf of Alaska. Near and
ahead of the trough axis, rain showers will be favored as a former
surface low pressure system winds down and deposits its moisture
across the state. The trough exits east into Yukon by Tuesday,
with a quickly- progressing ridge moving in to replace it across
southern mainland Alaska. As a result, rain showers diminish
across the region. Along the Aleutians, it is difficult to
pinpoint impacts from the potentially storm-force low, as there is
significant uncertainty in the track. Regardless, expect periods
of strong, gusty winds, potentially as strong as storm force.
Accompanying the low will also be tropical moisture with
precipitable water values of 1.5 inches or greater sourced from
Tropical Storm Peipah (currently located over southwestern Japan)
and strong dynamics which will lead to moderate to heavy rain
along the Aleutians on Monday.

For Tuesday, the low tracks near or just south of the Aleutians
toward the Alaska Peninsula and into the northern Gulf of Alaska.
The occluding low begins to lose some of its moisture tap and
strength, though its front, depending on track, may lift into the
Southwest Alaska coast near gale force. This would lead to a low
potential for some coastal flooding/erosion concerns on Tuesday,
though a more southern track would negate this potential. Light to
moderate rainfall begins to move inland over parts of Southwest
Alaska, regardless of track. In general, the low appears stronger
than the previous low, so winds and precipitation are expected to
be greater than what is seen on Friday and Saturday.

The low tracks somewhere in the vicinity of Kodiak Island by
Wednesday. Its front pushes east along the Gulf of Alaska coast,
where it may cause moderate to heavy rain along the coastal
mountains. The abundant moisture and weak to moderate cross-
barrier flow likely allows for at least some rainfall to push past
the coastal mountains into inland Southcentral at times. The low
continues to shift slowly eastward toward the end of the week,
keeping generally showery conditions in place across the southern
mainland, with heavier rain along the coast. For the Bering Sea
and Aleutians, surface high pressure moves in mid-week, though the
upper-level pattern appears fairly messy and the confidence in
any individual feature`s location is very low.

Quesada/DD

&&

.AVIATION...

PANC...A weak disturbance may bring a period of light rain and
potentially lower ceilings to MVFR early this morning before
lifting by mid-day. A Turnagain Arm wind is expected to develop
this evening and persist through Sunday morning.

&&


$$