743
FXAK68 PAFC 071249
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
449 AM AKDT Tue Oct 7 2025

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

Generally quiet weather is currently under way early this morning
across Southcentral Alaska. Water vapor imagery shows an amplifying
ridge off to the southwest with a cirrus shield quickly
overspreading northeastward into Southcentral. Meanwhile, the
remnant low pressure in the Gulf of Alaska continues to weaken as it
shifts towards SE AK. VIIRS Nighttime microphysics imagery shows a
few spots of low stratus and perhaps even fog across portions of the
area, but mainly remaining off the road system and out of
populated areas. Elsewhere, mostly clear skies to thin cirrus have
allowed temperatures to drop into the upper 30s to low 40s in
many places, though that`s still at or a few degrees above
average lows for this time of year.

While no significant weather is forecast in the short term, the
pressure gradient before the aforementioned ridge building from the
west and the surface low in the northern Gulf will sustain gusty
westerly winds through Whittier to near 30 knots. The pressure
gradient will do an abrupt 180 degrees on tonight as the Bering
trough and its front push into the Western Alaska Range and high
pressure builds over the Gulf. Additionally, gusty SE winds out of
the Turnagain Arm will bend into Anchorage this evening into
Wednesday. The arrival of the trough will also see the pressure
gradient tighten from the Shelikof Strait up into Cook Inlet, with
25 to 35 knot southerly winds gusting to as high as 40 knots.
Southerly winds across the higher elevations of Southcentral will
increase through the day on Wednesday as the trough lifts
northeastward. The Copper River wind, in particular, is expected to
intensify Wednesday morning with southerly gusts along the
Richardson Highway in the 35 to 40 mph range.

The biggest forecast uncertainty over the next few days entails
precipitation amounts across Southcentral on Wednesday. The highly
amplified pattern will result in a strong baroclinic zone extending
from the Alaska Peninsula up into the Western Alaska Range. This
zone will be characterized by broad difluent flow aloft and a plume
of deeper moisture advecting into interior Alaska within the
stronger southwesterly flow within the baroclinic zone. Forecast
models have a shortwave trough ride over the Gulf ridge, with
moisture spilling into the Susitna Valley initially, before
expanding east and southeast into the Talkeetnas and Western
Chugach. As a result, the Anchorage Bowl could see a few hundredths
of an inch to up to a tenth of an inch of rain, while areas on the
hillside may see a quarter of an inch of more. The mountains will
likely see the the most rainfall with the bulk of precipitation to
fall through the morning hours. Further north, the Mat-Su Valleys
could see anywhere from a tenth to two-tenths of an inch of rain.

-Brown/BL

&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Friday morning)...

Key Messages:

* Coastal Flood Advisory remains in effect for the Kuskokwim Delta
  Coast and Nunivak Island from this morning through Wednesday
  morning.

* Special Weather Statement for strong gusty winds along the
  Southern Alaska Peninsula today through tonight.

Discussion:

Warm air continues to advance across mainland Southwest Alaska
this morning as a ridge builds eastward across the eastern Bering
this morning as light rain continues across interior Southwest. A
broad Kamchatka trough continues to dig into the North Pacific as
a strong mid-960s mb surface low near Kamchatka continues to near
the Bering Strait by Wednesday morning. An atmospheric river
containing moderate to heavy rain across the Central Aleutians
will move eastward across the rest of the Aleutian Chain and the
Pribilof Islands through today and make it to the southern Alaska
Peninsula (AKPEN) by Wednesday morning. Light to moderate rain
associated with this atmospheric river also moves into mainland
Southwest this morning, but initially confined mostly to the
Kuskokwim Delta and Kuskokwim Delta Coast. Rain spreads into
Bristol Bay and interior Southwest by this afternoon and persists
through Wednesday afternoon. By Wednesday evening, rain tapers off
to showers across Southwest and the AKPEN with more persistent
rain remaining confined to the Western Alaska Range/Northern
Aleutian Range.

In addition to the rain, strong winds and coastal flooding will
be of concern beginning today for the Kuskokwim Delta Coast and
Nunivak Island. Elevated water levels are expected during high
tide cycles this morning as well as tonight. The highest water
push will occur with tonight`s high tide cycle. In general, expect
water level rise to be 1.5 to 3.5 feet above the normal highest
tide line. Thus, a Coastal Flood Advisory remains out for the
Kuskokwim Delta Coast and Nunivak Island through early Wednesday
morning. Strong gusty winds will also be likely along the
Kuskokwim Delta Coast and inland up to Bethel. Peak winds will
occur this afternoon through tonight. Gusts up to 55 mph are
likely along the coast with 40 to 50 mph inland to Bethel.

Strong gusty southerly winds are also likely along the southern
AKPEN today through tonight. Like the Kuskokwim Delta Coast, peak
winds along the southern AKPEN will occur this afternoon through
the overnight hours before slowly diminishing Wednesday morning.
Wind gusts along the southern AKPEN will range between 50 to 65
mph. Cold Bay has the best chance to see more persistent gusts to
65 mph. Therefore, a Special Weather Statement remains issued for
the southern AKPEN to bring further awareness to the strong gusty
wind threat.

Winds diminish area-wide during the day Wednesday. However,
persistent southwesterly winds into the Kuskokwim Delta Coast of
25 mph or so will continue Wednesday through Thursday morning.
Cold air, via westerly flow off the Bering, filters back across
Southwest Alaska from west to east starting Wednesday as the
trough axis draws near. What is left of the once broad Kamchatka
trough will finally make it coastal Southwest for Thursday which
will bring scattered showers back into the forecast for the
Kuskokwim Delta Coast and coastal Bristol Bay.

Returning back west, the next big weather-maker will takes shape
as a Sea of Okhotsk low moves across southern Kamchatka and into
the North Pacific by Wednesday. Its storm-force front looks to
deliver strong gusty southeast winds to the Western Aleutians for
Thursday. Moderate to heavy rain will also accompany this strong
front. Stay tuned for more forecast updates regarding this next
system that looks to first impact the Western Aleutians on
Thursday. There are indications that this system will also be the
main weather player for the end of the week and into the weekend.

&&


.LONG TERM FORECAST (Days 4 through 7: Friday through Monday)...

Southcentral Alaska will see high pressure build in on Friday,
leading to a decrease in precipitation chances and lower wind
speeds. Saturday sees a front move into the Gulf of Alaska in the
evening. This front will come with a large fetch of moisture,
allowing rainfall to begin in Kodiak Island, eventually moving up
into Cook Inlet. Sunday is more uncertain, but steadier rainfall
may move into the Anchorage and Mat-Su Valley regions. Winds will
increase, but are not expected to be very gusty. Lighter winds
aloft means that rainfall is more likely in the aforementioned
areas due to a lack of downsloping. Prince William Sound should
see heavy rainfall at this point as the front progresses eastward.
Sunday night sees a bit of a break in active weather due to
slight ridging before another front from the west moves into
Southcentral Alaska. This front will bring even more rainfall and
this time, gustier winds.

Starting from the beginning in Southwest Alaska has a front moving
through the Bering. By Friday night/early Saturday morning, gusty
winds will push into the Kuskokwim Delta Coast, causing water
levels to rise and may cause low level flooding. Weak ridging
builds in on Saturday over the Southwest mainland and the Eastern
Aleutians. This is short lived and a strong low that is associated
with the remnants of Halong moves up into the Bering. There is
some uncertainty with its intensity, but a swath of storm force
winds in the Central and Eastern Aleutians, then the Pribilof
Islands is likely. The low will quickly move northward and then
weakens by Monday. Behind the low is yet another low. Gale force
winds along the Aleutian Islands and along the Southwest Mainland
coast are possible by Monday afternoon. There is some
disagreement with the track and strength of the low, but models
are not too far off from one another.

-JAR

&&
.AVIATION...

PANC...VFR conditions will most likely persist through the TAF
period, with ceilings improving this morning in the wake of a
departing northern Gulf low. A light SSE wind will continue
through the early afternoon that could bend into the terminal
along with the chance of an isolated rain shower. Ceilings may
hover around or just below 5,000` late this afternoon. Winds
increase through the evening, with gusts as high as 20-25 kts by
tonight and Wed morning.

&&


$$