968
FXAK68 PAFC 130150
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
550 PM AKDT Sat Sep 12 2026

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

Clearing skies and seasonable temperatures across Southcentral
this afternoon as a weak frontal system shifts east and shears
apart toward the Alcan border. Rainfall amounts with this system
were unimpressive, with most lower-elevation areas only seeing a
few hundredths of an inch of precipitation. Areas of low clouds
remain trapped over the Mat-Su Valley and the higher elevation,
but should break up with time this evening as drier air filters in
from the northwest. An offshore flow develops tonight behind the
departing frontal system, resulting in gusty gap winds through
Seward and Whittier through Sunday.

Minimal change in the weather pattern through the rest of the
weekend as a Pacific ridge attempts to move high pressure back
into the region. This will result in mild and dry conditions
Sunday, with light winds and partly sunny skies. Mostly clear
skies will allow temperatures tomorrow morning to dip quite a bit
cooler than last night, particularly in the Copper River Basin
where overnight lows may reach near freezing. However,
temperatures are expected to rebound back into the low 60s
tomorrow afternoon for most lower-elevation spots.

A warm front extending from a Bering low pushes into
Southcentral Monday morning. Though much of the day will remain
dry, expect increasing cloud cover through the afternoon as this
system begins to filter in moisture-rich southwesterly flow. By
late Monday afternoon, chances for light rainfall gradually
increase across the Kenai Peninsula and shift northeast across
Anchorage and the Mat-Su Valley by the evening. By Tuesday morning
expect more widespread precipitation, spreading into Prince
William Sound. Concurrently, a strong coastal ridge develops along
the Northern Gulf Coast, bringing strong gap winds down the
Turnagain Arm and into Anchorage. This wet and windy pattern is
likely to continue into mid-week as the parent Bering low
continues to drift inland.

-CW

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: This morning through Tuesday afternoon)...

As of this afternoon, a front and trough axis remains draped from
Bristol Bay to the Central Aleutians and farther south down in
the North Pacific. With the front, there is a swath of rainfall
from the Bristol Bay waters to Adak along with sub-small craft
advisory level winds. Where it is not raining across the Bering
and Aleutians, fog, low stratus, and misty conditions are being
observed from the Central Aleutians and eastward. Due to a strong
~1032 mb North Pacific high to the front`s south and east, the
front will continue to stall over the course of the short term.
Having said that, moisture transport will continue to ride along
the boundary from the subtropics and tropics, keeping periods of
rainfall in the forecast. As the high slowly migrates eastward
over the next 24 to 48 hours, the corridor of precipitation will
shift eastward as well. Aloft, while the flow is currently zonal
across the domain, a robust, digging longwave trough is progged to
enter the Bering and stretch as far south as the North Pacific by
Monday morning. This will also help to nudge the vertically
stacked ridge farther eastward.

Downstream of the digging 500 mb trough in the midst of the
moisture advection from the North Pacific is a relatively weak
area of low pressure that moves across the Central and Eastern
Aleutians sometime Monday morning. Models have really been
struggling to capture this system, as there has been poor run-to-
run consistency with a lot of the guidance regarding timing and
location of the low. Normally, this would not be a big deal as the
low being depicted is fairly weak, but models are latching onto
the solution of the low deepening as it moves northeastward across
the Bering and into the Yukon-Kuskokwim Delta. Regarding model
uncertainty, the GFS has been the "most" consistent over its last
few runs and the EC has been trending towards the GFS. The NAM, on
the other hand, continues to go back and forth with poor run-to-
run consistency. So, with this forecast package, the consensus is
to lean into the GFS/EC solution. This means a relatively more
impactful system arriving to Yukon-Kuskokwim Delta by Monday
afternoon. The fetch of southwesterly winds associated with this
system does not look impressive, but what is interesting is that
most of the model guidance wants to continue to steadily deepen
the low just as it moves inland, and also shows westerly small
craft winds on the backside of the low sometime on Tuesday
morning. This last minute push of onshore winds may be enough to
cause minor water level rises and coastal erosion for locations
like Kipnuk. The probabilistic extratropical storm surge guidance
only wants to bring water levels barely above MHHW (Mean Higher
High Water) Tuesday morning. Due to the fact that almost all of
the models show the low strengthening on its approach to the
Kuskokwim Bay area, we will continue to closely monitor this
system. Stay tuned.

-AM

&&


.LONG TERM FORECAST (Wednesday through Saturday)...

A progressive pattern will bring more systems through the region
for the rest of the week. A Bering low tracks into Southwest
Alaska early Wednesday. While the model QPF values do not seem
high, the synoptic set up seems indicative for heavy rain in
Southcentral. There is enhanced upper level flow from a strong
ridge over the North Pacific and an upper level low over interior
Alaska. This southerly flow is bringing moisture from tropical
latitudes. Given the surface pressure gradient, there could be
strong gap winds through Southcentral as well as the Alaska
Peninsula. The exact track of the low will determine whether or
not there will be a strong Turnagain or Knik Arm wind during this
system. The upper level flow mentioned earlier winds down before
Thursday from the upper level ridge progressing eastward, shutting
down any chances of heavy rain or winds.

For the rest of the week, a weak trough in the Gulf will bring
mostly cloudy conditions with showers for Southcentral, Southwest,
and the Alaska Peninsula.

An upper level Kamchatka low will enter the Bering early Friday
and form a Bering low. West of Adak could see rain and wind on
Friday. The low is expected to strengthen through out Saturday and
will continue to move eastward. Models are not in agreement with
the exact track of this low given how far out in time. The system
should bring rain and windier conditions for the remainder of the
Aleutians. It is important to note that there is minimal
confidence of conditions reaching hazardous criteria for any of
the Aleutians.

-SS

 &&


.AVIATION...

PANC...VFR by late afternoon as a weather front moves east and
High pressure begins to briefly move back into the area. There is
expected to be mostly clear conditions overnight. Mostly clear
skies, along with weak flow aloft and at the surface, could allow
for fog formation late tonight into Sunday morning. Light and
variable winds will persist through most of the TAF period.

&&


$$