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FXAK68 PAFC 150018
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
418 PM AKDT Tue Oct 14 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Tonight through Friday)...

A negatively-tilted shortwave trough is lifting into the north
Gulf Coast this afternoon as an attendant compact low moves
onshore between Yakutat and Cordova. A shield of mostly cold rain
now extends along a deformation axis north of the low and trough
out to the eastern half of the Copper Basin. This band of rain
should end from southwest to northeast as the supporting low heads
off into the Yukon later tonight. Elsewhere, conditions are
relatively calm under a transient upper ridge heading into
Southcentral from the Gulf. Areas of low clouds and a few light
showers persist across the Anchorage, Mat-Su, and western Kenai
Peninsula areas, though this should also begin to clear out later
this evening as the upper ridge moves overhead.

By tomorrow morning, an occluded front vaulting ahead of a strong
low tracking over the Aleutians will quickly head northeast into
the Gulf, first brushing past Kodiak Island, then into the
northern Gulf by the afternoon hours. A corridor of gale force
winds will intensify to Storm force as the front approaches the
northern Gulf coast as a barrier jet forms ahead of the boundary.
These strong easterlies will affect the Barrens briefly on
Wednesday afternoon before the front continues to the north. A
secondary corridor of storm force winds will move south of Prince
William Sound Wednesday afternoon into Wednesday night before
winds rapidly weaken as the front moves onshore.

Aside from the marine impacts, strong easterly winds are also
expected to move up into the Kenai Mountains and Turnagain Arm,
but a sharp down-inlet gradient developing ahead of the front
will prevent strong winds from coming into Anchorage. However,
fairly strong winds gusting up to 40 mph will still pick up across
the Mat Valley out of the northeast Wednesday afternoon through
Wednesday night thanks to the same northeast to southwest pressure
gradient picking up ahead of the front. In terms of rainfall,
the heaviest rain will shift from Kodiak on Wednesday morning into
the eastern Kenai Peninsula and Prince William Sound Wednesday
afternoon. Most areas in the lee of the mountains (including the
Mat Valley and Anchorage) will stay dry through Wednesday night
due to the strong cross-barrier flow moving in ahead of the
front.

By early Thursday, the parent low currently moving over the
Aleutians will drift northeast into the Gulf and move south of
Prince William South by Thursday evening. Winds along the
coastline will mostly subside as winds up to gale force south of
the low shift from southerly to westerly over the open Gulf
waters. Steadier periods of rain will give way to scattered
showers as multiple weak waves rotating around the low pinwheel
into Southcentral. Unsettled and showery conditions will persist
into Friday as the low continues to degrade over the northern Gulf
and as a cooler air mass begins to filter in from the west across
the Alaska Range.

-AS

&&

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

Afternoon satellite analysis shows an incredibly large and complex
series of low pressure clusters south of Adak in the shape of a
large comma head. East of this cluster is a front barreling to the
east across the Aleutian Chain. Wind gusts at Unalaska peaked
around 60 MPH this afternoon. To the west strong gale force winds
are seen wrapping around the low in counter clockwise fashion.

The forecast for this low remains unchanged as it shifts to the
east. Despite the parent low weakening as slows down over Kodiak
Friday, it`s front will continue to slide to the east with gusto.
Winds and rain out of the southeast to east will reach Bristol Bay
late tonight, and push north and east through the morning hours.
Coastal winds will peak early afternoon on Wednesday. These
easterly winds are not favorable for coastal flooding, so coastal
communities will not be expecting any more significant coastal
flooding as this weather system affects the region. Elevated water
levels may still be possible during higher tide cycles. Strong
winds will be accompanied by light to moderate rainfall, with
around a half inch of rain expected for the Kuskokwim Delta Coast
through tomorrow night.

Northwest winds with gale force gusts and showery weather on the
back side of the low will continue for the Eastern Aleutians and
AKPen through Thursday morning as the low tracks towards the Gulf.
This northwest flow and cold air advection behind the low will
bring a change of airmass to the Bering and Southwest Alaska late
this week into the weekend, with low temperatures falling to
around freezing by Friday morning.

&&


.LONG TERM FORECAST (Days 4 through 7/Saturday through Tuesday)...

Starting with this weekend, all guidance points toward a continued
stormy pattern, with a highly amplified and strong subtropical jet
stream. However, there is a huge spread in operational model
guidance and poor run-to-run continuity with the handling of
individual storm systems. The hemispheric flow does look
progressive and favors a west to east storm track across the
southern tier of Alaska from the Aleutians and southern Bering Sea
to Bristol Bay and the Alaska Peninsula to the Gulf of Alaska and
north Gulf coast/Prince William Sound. These regions would be
favored for strong winds and heavy precipitation. Areas further
north would see lesser impacts from wind and precipitation.

By early next week, models indicate the jet stream becoming more
zonal and the center of the long-wave trough shifting just a bit
eastward (with some ridging indicated upstream over the Asian
continent). This could bring an end to this period of intense
storms that we have been experiencing over the past week.

-SEB

&&

.AVIATION...

PANC...Cigs and vis are improving quickly this afternoon as a
shortwave ridge builds in overhead and drier westerly flow moves
in off of the AK Range. Light and variable winds will become north
tomorrow morning and increase through the day as a front moves
into the Sound and a strong low pressure system near the Alaska
Peninsula begins to impact our area. There is a possibility of
LLWS as the front moves over the Chugach Mountains tomorrow, but
the shear layer level will depend on the strength of the northerly
down-Inlet flow. Cigs and vis should be VFR with the incoming
front.


&&


$$