867
FXAK68 PAFC 290001
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
401 PM AKDT Wed Oct 28 2026

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

The upper level high amplitude ridge which has been sitting over
Southcentral is shifting slowly eastward as a short-wave trough
and surface front very slowly approach from the Bering Sea.
Widespread dense fog this morning from the Mat Valley to Anchorage
and the western Kenai has been slow to erode, with some localized
areas persisting as of mid afternoon. Expect conditions to
continue to improve this afternoon and evening as higher clouds
move in. Low clouds and fog could persist for one more day in the
Copper Valley.

The forecast is mostly on track for tonight through Thursday with
the upper short-wave lifting northeastward to the Interior (up
and over the ridge) and the surface front stalling and dissipating
over the western Gulf, Cook Inlet, and the Susitna Valley. Expect
widespread light precipitation to develop through this corridor
tonight and persist into Thursday. The one addition is a Winter
Weather Advisory for the southern Susitna Valley. With deep
southerly flow ahead of the front, a layer of above freezing air
aloft will head for the southern Susitna overnight tonight through
Thursday afternoon, leading to a transition from snow to rain.
Surface temperatures will be slow to warm, especially in the
typically colder Willow area. Thus, a period of freezing rain with
a glaze to a tenth of an inch of ice accumulation are likely. This
has potential to produce slippery conditions along roads and
walkways tomorrow morning. Precipitation type for areas to the
south, from the Matanuska Valley to Anchorage and the Kenai
Peninsula will be in the form of rain with temperatures rising
through the 30s.

Attention then shifts to a large storm system in the Bering Sea,
which ingested the remnants of ex-Typhoon Champi. As this storm
settles in the Bering Sea on Thursday it will further amplify the
upper level flow. Initially, this will lead to strengthening
southerly upslope flow through much of the atmosphere and an
uptick in precipitation rates along the southern Kenai Peninsula
and Susitna Valley beginning Thursday afternoon. A strong
occluding front will then push into the Gulf Thursday night
accompanied by a strong jet streak (100-130 knots) and atmospheric
river. This will produce widespread impacts from heavy
precipitation and strong winds across much of the Gulf and
Southcentral Thursday night through Friday. The key theme for most
areas will be warm, wet, and windy, though a few key areas will
see heavy snow out of this. Here is a summary of products and the
most impactful weather in the forecast:

* A Winter Storm Warning has been issued for the northern Susitna
  Valley, including the Parks Highway corridor through Broad
  Pass, for heavy snow with accumulation of 7 to 15 inches.
  Upslope flow and heavy precipitation should safely keep
  precipitation type in the form of snow until perhaps Friday
  afternoon. Snowfall rates of up to an inch per hour are possible
  Thursday night through Friday morning.

* A Winter Weather Advisory has been issued for Thompson Pass for
  early Friday through early Saturday. Snowfall will not be as
  heavy as in the northern Susitna Valley, but rates of half an
  inch per hour will lead to low visibilities and travel could
  become difficult at times.

* A Flood Watch has been issued for Seward for Thursday evening
  through Friday evening. Deep southerly flow right up
  Resurrection Bay is favorable for heavy rain at sea level in
  Seward and vicinity. Rainfall rates up to a quarter inch per
  hour could lead to flooding of smaller streams and creeks along
  with standing water on area roads. Heavy rain is expect across
  all of the Prince William Sound and embedded communities, but
  Seward is the most likely area to see flooding.

* Strong southeasterly gap winds will affect Turnagain Arm, the
  Anchorage Hillside, south to west Anchorage, the Knik River
  Valley out across portions of Palmer and Wasilla, and the
  Copper River Valley.

* The front will stall as it crosses the northern Gulf and Prince
  William Sound. A barrier jet will form ahead of the front and
  bring a prolonged period of Gale to Storm Force winds to coastal
  waters.

* For more details on expected weather for your area visit
  www.weather.gov/anchorage.

The worst of the weather will come to an end by Friday afternoon
as the front and atmospheric river exit to the eastern Gulf. A
large upper level trough will settle over the region, maintaining
clouds and areas of light rain as we head into the weekend.

-SEB

&&


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

A front is currently bringing a swath of rainfall and gusty winds
to Southwest Alaska and the Alaska Peninsula this afternoon. The
rain and gusty winds will diminish during the evening hours as a
weak and short lived ridge builds in from the west. A subsidence
inversion during the morning hours on Thursday will lead to areas
of patchy fog for coastal Southwest and the Alaska Peninsula.

A large upper low associated with the remnants of Ex-Typhoon
Champi moves into the western Bering early Thursday morning. This
low continues to have a high likelihood of bringing storm and gale
force winds to the Aleutians, especially from Shemya to Atka.
Seas up to 20 ft will spread across much of the western Bering
while propagating across the Pribilof Islands and along the Bering
side of the Aleutians to just offshore of Cold Bay. Meanwhile,
higher seas up to 30 to 35 ft will be possible on the Pacific side
of the Western Aleutians on Thursday.

Further east, south to southwest flow into the Kuskokwim Delta
will continue through Friday. Coastal erosion will be possible
with the sustained southerly winds into the Kuskokwim Delta. The
tide cycle is nearly at its peak, which should allow water levels
to be slightly higher than the previous event Monday into Tuesday.
There is a coastal flood advisory for the Kuskokwim Delta for
water levels reaching 1.5 to 3 feet above the normal highest tide.
The highest water levels for Kipnuk and Kwigillingok are likely
to be around 2.5 feet and 2 feet respectively. The advisory is in
effect from 11 pm Thursday to 7 am Saturday.

As the low moves southeastward towards the Gulf of Alaska on
Saturday, winds will flip in direction for Coastal Southwest
Alaska, alleviating the Kuskokwim Coast of coastal flooding
potential. Cooler air filters in at this point, so any lingering
showers along and north of the Kilbuck Mountains will be snow or a
rain/snow mix depending on the extent of colder temperatures.
Meanwhile, a strong front moves into the Bering from the west,
bringing more winds and rainfall with it.


&&

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

No significant changes to the long term forecast depicting a
persistent active pattern with widespread unsettled weather across
most of the forecast area.

By Sunday, the global models are in fairly good agreement and
depict a large, occluded area of low pressure system moving into
the southwestern Gulf of Alaska by Sunday morning. Cold air
advection and a stout northwesterly flow in the boundary layer
will lend to gale-force winds and gusts through bays and passes of
the AKPen and eastern half of the Aleutian Chain through Sunday
morning. Farther east, there remains good agreement that the front
associated with the low will be over the northeastern Gulf coast.
However, there is uncertainty in how far east and how far west the
barrier jet ahead of the front will extend. The GFS continues to
be the outlier with this jet still extended into Prince William
Sound. Showers will also linger for the AKPen, Kodiak Island, and
Southcentral coast Sunday as moisture continues to wrap around the
low with precipitation enhanced by various vorticity lobes also
rotating around the upper-level low.

By late Sunday into Monday, attention shifts back to the western
Bering and Aleutians as yet another strong Kamchatka Low swings a
high-end gale to storm force front over this area. This system
becomes more complex as various surface lows spin up along the
front with what looks to be a second surface low diving south,
undercutting the aforementioned low, and reinforcing both a core
of very strong winds and heavy precipitation. There is high
uncertainty between the various forecast models as to how this
complex low setup evolves as it moves east over the Bering and
toward the mainland. However, the main takeaway is that there is
high confidence in the development of a broad upper-level trough
and surface low over the southern Bering by Monday with very
strong westerly winds across at least the western two thirds of
the Bering and Aleutians and strong southeasterly winds along a
front driving east toward coastal Southwest Alaska. By late Monday
into Tuesday, this system looks to remain somewhere over the
eastern or southeastern Bering with its front moving over the
Gulf of Alaska and the Kenai Peninsula. This solutions would
favor another strong wind event for the Gulf of Alaska coastal
waters, strong gusty southeasterly gap winds for typically favored
locations, and yet another round of heavy precipitation for the
coastal mountains and upslope areas of the Talkeetna and Alaska
Ranges. The threat for gusty winds and heavy precipitation remains
into Wednesday.

-TM

&&


.AVIATION...

PANC...Patchy dense fog may continue through mid to late
afternoon, reducing visibilities to one-quarter mile or less. Once
the fog lifts, VFR conditions and light north-northeasterly winds
will persist. Low level wind shear is likely late this afternoon
through tonight, and again early to mid morning Thursday through
early to mid afternoon Thursday, with southerly winds aloft at
30-40 mph. A southeasterly wind through Turnagain Pass will
develop by late this afternoon. There is a chance (40-50%) that
this wind clips the terminal at times between 9 PM this evening
and 3 AM thursday morning. Any southeasterly wind that does move
over the terminal will likely limit LLWS potential. Light rain
moves over the terminal late tonight with cloud ceilings falling
below 5000 feet then to below 3000 feet by mid-morning Thursday.


&&


$$