449
FXAK68 PAFC 291315
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
515 AM AKDT Thu Oct 29 2026

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

A short wave is moving through Southcentral this morning bringing
precipitation into the Cook Inlet and MatSu regions. The winter
weather advisory for the central Susitna Valley remains in effect
this morning as the surface air over much of this area has
remained right around freezing with warmer air aloft moving over
the region. This is causing freezing rain in Talkeetna early this
morning and a mix of rain and freezing rain across the central
Susitna Valley depending on temperature which range from 30 to 34
degrees across that region. This freezing rain is expected to end
by later this morning as it transitions to rain with warming
surface temperatures.

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 generally in the mid to upper 30s. However,
there may be colder areas around Anchorage (especially near the
Campbell Tract area) and the Matanuska Valley that will see
pockets of freezing rain early this morning, but nothing
widespread is expected in these areas.

Attention now shifts to the large storm in the Bering Sea. As
this storm heads eastward, 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. However, areas in the
immediate lee of the Kenai, Chugach and Talkeetna Mountains will
likely see less rainfall this afternoon due to cross-barrier flow
bringing in downsloping winds across these mountains.

By tonight, a strong occluding front will push into the Gulf,
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 tonight
through Friday. The key theme for most areas will be warm, wet,
and windy, though a few 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 tonight 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 This evening
  through Friday evening. Deep southerly flow 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 Basin.

* 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.

-EZ/SEB

&&


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

Currently, a front from a large low associated with the remnants
of Ex-Typhoon Champi has moved into the Bering. The front is over
the Pribilof Islands to the Eastern Aleutians and will push inland
by this afternoon. For the low itself, storm force and gale force
winds on the south side of the low impacts the Aleutians from
Shemya to near Adak. South to southwest flow will impact the
Kuskokwim Delta through Friday, which is expected to cause minor
coastal flooding. A Coastal Flood Advisory remains in effect for
the Kuskokwim Delta Coast for water levels reaching 1.5 to 3 feet
above the normal highest tide. The most likely peak water levels
for Kipnuk and Kwigillingok are likely to be around 2.5 feet and 2
feet respectively. The Advisory remains in effect through 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 over the mainland will be snow or a rain/snow mix
depending on how cold temperatures get. Meanwhile, a strong front
moves into the Bering from the west, bringing more winds and
rainfall with it. This front originates from a strong low that
will move into the Bering by Sunday. More gale to storm force
winds will impact the Shemya area by Sunday afternoon when the low
arrives. Meanwhile, the aforemetioned front will traverse
eastward, bringing a large swath of rain or rain/snow and gusty
winds along with it. By Sunday afternoon, the front stretches from
Saint Matthew Island, through the Pribilof Islands to the
Unalaska and Cold Bay area.

-JAR/SS

&&
.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...Low level wind shear is likely into this afternoon with
variable surface winds and southeasterly winds 25 to 35 kt at 2000
ft or less. Sometime late this afternoon to early evening, the
southeasterly wind through Turnagain Arm will move over the
airport with winds gusting 25 to 30 kt. there is potential for
these winds to move in and out over the course of the day which
would make wind conditions rather erratic until the stronger
Turnagain Arm winds take over by this evening.

Rainfall will be light and ceilings are expected to be mainly
VFR. However, there may be some brief periods of MVFR ceilings
this morning. Some more persistent rain is expected to develop
this evening and overnight, but VFR conditions are expected to
prevail due to the wind keeping the lower atmosphere mixed enough
to keep it from saturating. If winds end up being weaker, there
would be a better chance for ceilings to dip into MVFR conditions
this evening and overnight.

&&


$$