Gateway, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

562
FXAK68 PAFC 121325
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
525 AM AKDT Sun Jul 12 2026

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

Discussion:

A broad upper low remains anchored over the Seward Peninsula this
morning, with a longwave trough spanning the Bering and Southwest
Alaska. Several disturbances are forecast to track through the
base of the trough and cross into Southcentral. Yesterday`s trough
axis over the Susitna Valley and Kenai Peninsula will be
overtaken and reinforced by the next shortwave emerging from
Southwest Alaska into the western Gulf this afternoon and tonight.
The end result will be expanding showers across Southcentral and
a slow-moving front into Prince William Sound. Morning radar shows
an axis of precipitation already stretching from south of the
Kenai Peninsula up into the Mat-Su and slowly lifting northward.
Coastal ridging and strengthening easterly flow aloft should
result in downsloping moisture for areas west of the Chugach,
limiting overall rain totals for Anchorage. Meanwhile, the Copper
River Basin remains forecast to see drier conditions with the best
chances for rain expected over the mountains.

The forecast thinking remains mostly unchanged for early next
week late Monday into Tuesday. A new low pressure system over
Bristol Bay will push a front and a newly tightened pressure
gradient in Southcentral, favorable for winds channeling through
gaps. This will also bring another wet low pressure system over
Kodiak Island early next week. Uncertainty remains with the
progression and speed of this system, but forecast models show a
faster moving trough overspreading Kodiak Island Monday afternoon,
amplifying over Southcentral Tuesday morning. Rain chances will
temporarily diminish on Monday with the exception of the Gulf
coast and coastal mountains. Then rain chances return in earnest
on Tuesday as upper level diffluence overspreads the region. Near
Anchorage, there is increased potential for strong winds to
develop out of the Turnagain Arm Tuesday morning. Strong and gusty
winds will be possible through the Arm, and depending on how
these winds move over Cook Inlet, may span into the southern reach
of Anchorage, including the Hillside, Rabbit Creek, and Potter
Valley.

-BL/CL

&&


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

Satellite imagery shows an occluded low pressure system near
Nunivak Island and moving northward with time. This feature along
with its associated surface trough/front is bringing widespread
light rain for much of interior Southwest Alaska this morning.
Also shown on satellite is the northern fringes of a North Pacific
system working its way northward and a shortwave dropping
southward over the Bering from eastern Russia. Much of the Bering
and western Alaska in general is under the influence of persistent
500 mb longwave troughing, containing both an upper low over the
Yukon-Kuskokwim Delta and the aforementioned shortwave. Southwest
Alaska is on track to evolve into more showery weather for a time
as the upper level trough becomes increasingly negatively tilted
and upper level support lifts northward and out of the area today.
Meanwhile, as the aforementioned shortwave digs farther south and
east over the Bering, a weak surface low forms and brings in
precipitation mostly south of the Pribilof Islands by this
afternoon.

The 500 mb pattern becomes increasingly amplified through this
afternoon as a closed upper low/trough complex rotates
northeastward around anti-cyclonic flow from ridging over the
North Pacific. This will set the stage for a moisture-rich North
Pacific low to move towards the Central and Eastern Aleutians by
late this evening. This low is on track to cross the Aleutians and
move across the southeastern Bering Sea through Tuesday morning,
bringing a moisture-rich fetch of warm air from the Pacific and
more rainfall across the Aleutian Chain and to Southwest Alaska
through Tuesday. Of more interest with this system is the renewed
possibility of marine lightning and isolated thunderstorms
beginning Monday morning for the coastal zones south of Adak/Atka,
eventually spreading east to the eastern Aleutians and Alaska
Peninsula through Tuesday morning.

Confidence on marine lightning potential has increased since
yesterday as models show ingredients coming together Monday
morning; a theta-e ridge building in from the south downstream of
a digging 500 mb trough and a 300 mb jet streak embedded within
the eastern flank of the trough. Due to the northeast-southwest
orientation of the jet streak as depicted by the GFS/EC, south of
the Aleutians and Alaska Peninsula would be under the right
entrance region of the jet streak - which is an area of synoptic
vertical ascent, which would enhance the risk of marine lightning.
The theta-e ridge and digging trough moves eastward through
Tuesday morning, though confidence remains low to medium (30-40%)
of marine lightning Tuesday morning south of the Alaska Peninsula.
It would not be out of the realm of possibility to see lightning
over Bristol Bay Tuesday morning as well, as the GFS/EC agree that
this area would be under the left exit region of the 300 mb jet
streak, which is another ideal location of synoptic vertical lift.
Stay tuned.

-AM/JH



&&


.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

Just in case you were hoping for a major pattern change... not
yet. An active and relatively cool weather pattern remains in
place across Alaska through the end of the week as a broad
longwave through persists over the Mainland. Embedded shortwaves
rotating through the flow will continue to bring periods of rain
to much of Southwest and Southcentral Alaska through the longer
term period, with locally moderate rainfall possible where
stronger disturbances track inland. Temperatures are expected to
remain near to slightly below seasonal normals, with plenty of
cloud cover keeping conditions feeling cool. Inland winds
generally remain light, while breezier conditions persist along
the Gulf Coast and adjacent marine waters.

Farther west, ridging over the Bering Sea gradually shifts east as
a series of North Pacific lows approach. This will allow
increasing clouds, rain, and strengthening winds to spread
eastward across the Aleutians and Bering before eventually
expanding into western portions of the Mainland. The overall
pattern remains progressive, with little opportunity for prolonged
drying.

Forecast confidence decreases somewhat late in the week as
guidance continues to differ on the timing and track of additional
shortwaves and surface lows. Despite these differences, confidence
remains high in the overall unsettled pattern. Another North
Pacific low is excepted to move into the Gulf by late week,
maintaining widespread cloud cover and periods of rain across
Southern Alaska into Saturday, while additional showers linger
father inland. Gusty coastal winds will accompany the stronger
systems, particularly along the Gulf Coast and portions of the
Alaska Peninsula. Temperatures are expected to remain on the cool
side through the weekend as persistent cloud cover and recurring
rainfall continue across much of the state.

LM


&&


.AVIATION...

PANC...Scattered showers on Sunday will contribute to mostly MVFR
ceilings on Sunday, with potential for intermittent IFR ceilings
through early this afternoon. Conditions should improve this
afternoon as upper level energy lifts north of the Alaska Range,
though light rain could linger into tonight with MVFR conditions
persisting through Monday morning. Southeast winds up to 20 knots
are forecast late this evening before weakening overnight.

&&


$$