838
FXAK68 PAFC 280118
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
518 PM AKDT Fri Jun 27 2025

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

The overall thinking for the near term has not changed much from
yesterday. Satellite still shows an occluded low south of Kodiak
Island, which in turn is sending a weak, occluded front towards
the Gulf coast. Ahead of the front, an easterly upper level wave
has provided enough forcing for showery conditions to persist
along the coast and even some drizzle for the Anchorage area. As
the front slowly advances northward this afternoon and evening,
coastal ridging will slowly try to erode away, allowing for
overall pressure gradients to decrease, which could help relax gap
winds somewhat across the Turnagain Arm, Knik Arm, and Copper
River Basin. However, to counter that, a thermal trough to the
northwest could still keep these locations a little gusty this
afternoon.

Looking aloft, the longwave troughing pattern has become more
amplified, which will likely impact weekend weather. A broad upper
level low is situated in the Gulf, vertically stacked with the
surface low, with shortwaves rotating around its periphery. A
rather robust shortwave is located on its southern flank, and that
will be part the main weather maker for the weekend for
Southcentral. Weaker easterly waves are now moving into the Copper
River Basin and parts of the interior, but convection should be
limited this evening due to increasing cloud cover. The only
exceptions will likely be confined to the northeastern Copper
River Basin.

The short term becomes rather tricky with the details. Although
there is relatively high confidence regarding rainfall for this
weekend across Southcentral, forecast timing has been the main
challenge as models are still struggling to come into agreement.
First, a few showers and isolated thunderstorms may develop along
the foothills of higher elevations, including the Alaska Range and
the eastern slopes of the Talkeetna mountains as soon as Saturday
afternoon and evening as the aforementioned vigorous easterly
shortwave makes progress rounding the upper level low in the Gulf.
Locally heavy downpours are possible in these locations as lapse
rates steepen as cooler air moves in aloft. Due to the sharper and
amplified pattern, the flow of the main axis of precipitation
will likely move northeast to southwest. Overall storm motion and
instability ahead of the wave may drag some convective cells as
far south as Palmer for a time Saturday evening into Sunday
morning. Models are in better agreement of precipitation
developing than they were yesterday, but diverge on the timing and
extent of storm activity. Hopefully, overnight guidance comes in
with more agreement. However, there is above average confidence
that much of Southcentral could see a wetting to soaking rain at
some point later this weekend.

-McCormick/Rux

&&


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

The large low in the Gulf continues to sit and spin south of
Kodiak Island today; this will be the case through Sunday.
Numerous shortwaves continue to rotate around this low and across
Southwest Alaska also through Sunday. Scattered showers will move
into western portions of the Kuskokwim Valley and interior
Kuskokwim Delta by this evening and continue into the morning
hours Saturday. Showers and isolated thunderstorms are likely for
Saturday afternoon and evening across interior Bristol Bay and
along the Western Alaska Range with the best chances for lightning
strikes being across the Western Alaska Range. There is a low
chance for a lightning strike or two near Dillingham Saturday
afternoon and evening but confidence is low. Confidence is a
little higher for a few strikes around the King Salmon area. For
Sunday, a wave of moisture rides over top an easterly propagating
ridge in the Bering Sea and gives Nunivak Island, the Kuskokwim
Delta Coast, and the southern Alaska Peninsula (AKPEN) a round of
showers Sunday morning. The interior sees another chance for
isolated thunderstorms Sunday afternoon and evening mostly
centered along the Western Alaska Range. The setup for Sunday does
not appear to be as widespread as what will be witnessed for
Saturday as far as lightning strikes are concerned.

Further west, a large area of high pressure occupies much of the
Bering through Saturday. Behind this ridge, an area of low
pressure near Kamchatka will move eastward into the western Bering
by Monday. First, its front moves across the Western Aleutians and
western Bering Saturday morning into the evening as the ridge
begins to weaken to the east. There will be a west to east moving
corridor of gale-force winds across the western and central
Bering Saturday through Sunday. Most precipitation with this
system will stay confined to the Bering Sea itself with some light
to moderate rain across the Western Aleutians Saturday before it
moves off to the north by Saturday evening. Warm air from the
tropical Pacific moves in behind the front starting Saturday
evening as does additional moisture. Showers move back into the
Western Aleutians for Sunday as the front makes it to the Pribilof
Islands by then. Light to moderate rain moves into the Pribilof
Island late Sunday morning to early Sunday afternoon and then to
the mainland southwest coast by Sunday night. Expect widespread
light to moderate rains across the Kuskokwim Delta, coastal
Bristol Bay, and the AKPEN for Monday. The front and rain pushes
inland to the Kuskokwim Valley and interior Bristol Bay for
Monday evening as showers look to continue across the Aleutian
Chain then.

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

A broad, closed upper level low continues to reside in the Gulf
of Alaska while high pressure strengthens in Interior Alaska at
the start of the long term forecast period. A fast moving low in
the southern Bering Sea will push the remnants of Tropical
Depression Sepat across the Alaska Peninsula on Tuesday, bringing
enhanced winds and rain to the region before phasing with the Gulf
low on Wednesday. An omega block pattern looks to take shape by
Thursday with a Kamchatka low drifting to the central Bering,
closed high pressure interior, and the resident low pressure
system in the northern Gulf. Easterly shortwave troughs moving
through the Gulf low will likely bring periods of rain showers to
the southern coast through the week, but north-south positioning
of the system will have an impact on how far inland we will see
precipitation. Generally warmer than normal temperatures are
expected over interior locations by the second half of the week
while coastal areas will remain moderated.

&&


.AVIATION...

PANC...VFR conditions prevail through the TAF period with
sprinkles or occasional very light rain possible over the terminal
through this evening and again Saturday morning. Light and
variable wind this afternoon will likely become southeasterly
later this evening as winds through Turnagain Arm develop. Any
southeasterly wind clipping the terminal this evening is expected
to be weaker than that observed that previous two days, with gusts
around 20 kt. Winds become light again around early morning
Saturday.


&&


$$