756
FXAK68 PAFC 161302
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
502 AM AKDT Mon Jun 16 2025

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

Generally warm and dry weather with a few chances of showers and
even a couple thunderstorms is in store for Southcentral AK during
the first few days of the week thanks to a ridge of high pressure
sitting across the Interior. Nighttime microphysics imagery notes a
stratus deck that stretches from Kodiak Island northward through
Cook Inlet across the Kenai into Anchorage and the Mat Valley. This
deck should gradually dissipate today with increased diurnal mixing,
resulting in clearing skies this afternoon. Several convection-
allowing models are advertising showery activity developing this
afternoon across the Wrangells and Copper River Basin and then
moving westward through the Talkeetnas and the northern Susitna
Valley late afternoon and evening. Enough instability should be
available to also squeeze out a thunderstorm or two today.

Heading into tonight, a trough rotating around a low in the Gulf of
Alaska will pivot across Southcentral AK, bringing a chance of rain
and some increased winds to the Kenai Peninsula, Turnagain Arm, and
Anchorage late tonight into early tomorrow morning. Showers,
particularly lee of the mountains, will be scattered in nature.
Can`t rule out some thunderstorms, but instability will remain
marginal with this trough overnight. Clearing skies behind this
trough should return pleasant weather by late Tuesday.

Seasonable weather will continue Wednesday as the area remains under
the influence of a ridge of high pressure centered across Interior
Alaska. Isolated to scattered showers are likely in the afternoon,
particularly across higher terrain, with temperatures right near
average for this time of year.

-Brown

&&

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

The Bering Sea, Aleutian Islands, and coastal Southwest Alaska are
currently under the influence of two low pressure systems: one
near Saint Matthew Island in the Northern Bering Sea, and one
just south of the Alaska Peninsula in the North Pacific.
Meanwhile, high pressure is bringing clearer skies and warmer
temperatures to interior Southwest Alaska.

Southwest Alaska will continue to see hot and mostly dry
conditions through at least mid-week, with highest temperatures
ranging 70-79F in the lower Kuskokwim Valley and upper 60`s
elsewhere. These warm surface temperatures generally promote
favorable environments for thunderstorm development. Chances are
high that we`ll see some lightning by Tuesday over interior
Southwest Alaska, with the most likely location being Kuskokwim
Valley, Lime Village, and the northern reaches of Bristol Bay
Borough. However, the intensity and location of these
thunderstorms continues to be a bit challenging to forecast.
Models have generally been trending towards more organized upper
level shortwaves moving east to west across Southwest Alaska. This
could lead to greater cloud cover, making the environment less
conducive to thunderstorms than currently forecast. In addition,
the more organized upper level shortwaves could lead to the
development of a weak surface low near Bristol Bay, which could
advect in a more stable, maritime air mass that limits convection.

Further west, small craft winds with a small pocket of gales will
persist for the marine areas south of the Eastern Aleutians and
southern Alaska Peninsula with elevated winds to 20 mph over the
land areas through this afternoon. Periods of rain showers for the
aforementioned areas this morning tapering of though late
afternoon/early evening as the low tracks southeast into the North
Pacific. By Wednesday afternoon, another North Pacific low begins
to approach the Western and Central Aleutians. Gale-force winds
are possible, and the decent moisture advection associated with
this storm will likely bring moderate to heavy rain for the
Central Aleutians.

&&

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

For much of the long term, the operational models agree that the
upper level ridge of high pressure that has been situated across
interior Southcentral will remain steady-state and anchored in
place, keeping temperatures generally warmer than average. The
ridging will also keep an upper level easterly to northeasterly
flow, allowing for more hazy skies from the Canadian wildfires,
particularly for the Copper River Basin. This flow regime will be
reinforced by a large upper level low across the Gulf of Alaska.
Afternoon and evening showers and thunderstorms will be likely
confined to the northern Susitna Valley and Copper River Basin.
There is also fair agreement at the end of the long term of a
large upper low in the Bering with smaller shortwaves rotating
around its periphery that may help nudge and erode the ridge
across Southcentral and force it to lift to the north. At the same
time, for the Aleutian chain, there is average confidence of a
large low pressure system moving out of the North Pacific and
across the islands and retrograding to the northwest with its
front becoming more elongated and pushing into the western Gulf of
Alaska.

-AM

&&

.AVIATION...

PANC...A 2-3kft marine stratus layer prevails across much of the
area, including for ANC, thanks to light southwest flow up the
Cook Inlet. An upper-level wave combined with diurnal heating will
help dissipate this layer by the afternoon. Expect winds to be
mostly light and out of the southwest through Monday evening.
There is high potential for Turnagain Arm winds to bend into the
terminal by Tuesday morning as a coastal ridge develops and re-
orients pressure gradient to allow for gusty southeast winds.

&&


$$