King Lake, Alaska Weather Forecast Discussion

608
FXAK68 PAFC 011346
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
546 AM AKDT Wed Oct 1 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
A frontal system is moving in from the west that is bringing both
an increase in cloud cover and southeasterly gap winds through
Turnagain Arm this morning. Gusts for the Knik River Valley will
continue to gradually increase through the rest of this morning
and the Copper River Valley will see an increase by this
afternoon. The combination of increased clouds and wind will allow
for temperatures to warm in advance of the precipitation
associated with the front.
The aforementioned precipitation will overspread the Susitna
Valley by mid-morning and late-morning to early afternoon for the
Kenai Peninsula, Anchorage Bowl, Mat Valley, and Prince William
Sound areas. A strong south to southwest flow along the front and
upper-level trough will allow precipitation to fill in over Cook
Inlet, with the heaviest precipitation for upslope areas of the
northern Susitna Valley, Hatcher Pass, and Kenai and Chugach
Mountains. Kodiak City may have showers, but the prevailing flow
pattern will be favorable for some downsloping into town. Snow
levels will rise to around 3,500 ft by this afternoon. Thus, any
snow accumulation will be confined to the mountains as well as the
northern half of Broad Pass and the extreme northern and western
Copper River Basin.
As the upper-level wave drives into Southwest Alaska later today,
a new surface low will spin up near southern Cook Inlet and drive
east through Thursday. This new system, along with its upper-
level support, stout moisture advection and southerly winds aloft,
will drive ample moisture and precipitation into the northern
Susitna Valley, Talkeetna Mountains, Prince William Sound, and
Chugach Mountains through late Thursday. Upwards for an inch or
more of rain is possible around Talkeetna with less than an inch
from Kenai to Anchorage and Palmer. Closer to 2 to 3 inches of
rain is likely from Valdez to Cordova, with locally higher amounts
at elevation.
For locations that do see cooler temperatures and snow potential,
light accumulations, on the order of 1 to 3 inches, is possible
for Paxson and Eureka. 6 to 12 inches of snow could fall at
Summit Lake in Hatcher Pass. What`s that saying?...Winter is
coming!
As the low moves into then east of Prince William Sound, the
southerly gap winds, with gusts around 30 mph for parts of
Anchorage, the Matanuska Valley, and Copper River Valley, will
quickly diminish then become more northerly as colder air moves
in behind the low. Westerly and northerly gap winds are then
expected for Whittier and Seward, respectively, by Thursday
afternoon and lingering into Friday as precipitation quickly
comes to an end from west to east. A brief shower could return
Friday night through Sunday morning across the Matanuska-Susitna
Valley and higher elevations.
-TM/Rux
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3/Today through Saturday)...
Currently, as of 5 AM Wednesday, there is a large low just south
of the Bering Strait. A front from this low has moved across the
East Bering and is passing through the Southwest Mainland.
Widespread precipitation is being seen from the Andreanof Islands
throughout the rest of the Aleutians, Alaska Peninsula and the
mainland. The reason for such a large swath of precipitation is
due to a North Pacific low south of the Central Aleutians that
the aforementioned low is in phase with. This line of
precipitation will quickly move eastward through the course of the
day. Southerly flow is allowing for temperatures to remain warmer
than they have been as of late. The upper trough south of the
Bering Strait will dip into the Southwest Mainland by Wednesday
night/Thursday morning, prolonging precipitation chances and
allowing for an area of small craft winds to impact the Pribilof
Islands. The trough will also bring in colder air, so temperatures
in the mainland will become cooler. Behind all of the action is a
building ridge. This ridge will move eastward and envelop the
Eastern Bering by Thursday. Precipitation chances and winds will
diminish as a result of this ridge. The ridge will flatten out and
flow will become zonal by Thursday evening.
Friday sees a low move into the Western Aleutians. This low will
bring gale force winds and moderate to heavy precipitation along
with it as it moves eastward. By Friday evening into Saturday
morning, the low will bring gale force winds to the Eastern
Aleutian and the Pribilof Islands. The low will then take a
northward turn, with its center arriving west of Nunivak Island
by Saturday morning. The low will bring southerly gale force winds
into the Kuskokwim Delta coast, increasing wave heights for
communities along the coast. A near full moon along with an
extended period of gusty winds (~24 hours) could allow for coastal
flooding issues for these communities. Confidence has been
increasing for this low`s track, but even minute differences could
lead to different outcomes, so continue to monitor the forecast
for updates. A more unsettled pattern remains in the Bering for
the rest of the weekend as upper level troughing sets in. Expect
more active weather to continue next week.
-JAR
&&
.LONG TERM FORECAST (Days 4 through 7: Saturday through
Wednesday)...
The weekend starts out with a deep upper level low/trough
extending from the Chukchi Sea through the Bering Sea, Western
Aleutian islands and into the North Pacific with troughs rotating
through the region. These troughs will produce potentially strong
surface features, keeping the conditions unsettled across the
area. A significant deepening 970 mb low will cross the Bering
Sea before weakening slightly as it moves towards the Bering
Strait and Western AK Sunday and into Monday. The main concern
with this system will be possible gale force winds across the
Western Aleutians and steady strong southwesterly winds and
coastal erosion in the communities along the central west coast
of the state.
A second Sea of Okhotsk low will quickly pass over the Aleutians
and southern Bering sea and cross the Alaska
Peninsula on Tuesday then track northwestward to the Gulf of
Alaska impacting Southcentral towards the end of the forecast
period. There is a potential to see gale force winds and heavy
precipitation with this system as it passes over the Aleutians and
Bristol Bay and along the Gulf coast. Some snow accumulation
above the Pass levels is possible.
&&
.AVIATION...
PANC... A front moving through the area will bring steady rain
throughout most of the TAF period. Conditions may lower into MVFR
especially for the this afternoon through tonight. Winds from
Turnagain Arm are expected to bend into the terminal. Gusts of
around 25 kt can be expected, though a brief gust up to 30 to 35
kt is possible this afternoon. Winds decrease tonight along with
precipitation and should be out of the area by Thursday afternoon.
&&
$$

NWS AFC Office Area Forecast Discussion