559
FXAK68 PAFC 150036
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
436 PM AKDT Fri Jun 14 2024

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

Summer has arrived to Southcentral, at least through early next
week, with widespread upper 60s and lower 70s temperatures being
achieved this afternoon. Talkeetna is currently sitting at 78
degrees and the observation in Bentalit has hit 80 degrees.

High pressure ridging in from the west and weak northerly flow
aloft is allowing for clear skies and proper daytime heating. Cu
fields have been percolating across the Copper River Basin, as
well as the Susitna Valley to a lesser extent, with weak
instability contributing to scattered showers and isolated to
scattered wet thunderstorm chances. A current look at satellite
shows a couple of storms attempting to move into the Copper River
Basin from near the ALCAN border. Lightning is also noted south of
Glennallen, west of the Richardson Hwy. Through this evening
additional storms will be possible. Northeasterly steering flow
will transport storms in a southwest direction before eventual
loss of instability results in storms and showers dissipating.

Saturday will be somewhat of a repeat of Friday with little to no
change in the weather pattern, but with the warmest temperatures
of the year expected across Southcentral, as well as even higher
thunderstorm chances. While the bulk of storms will form out over
the Copper River Basin and Mat-Su Valleys, it`s not out of the
question that a stray storm drifts into the Anchorage Bowl, with
additional storms developing over the Western Kenai Peninsula.
Into Sunday high pressure shifts directly atop the Copper River
Basin. This will actually suppress thunderstorm chances for the
Copper River Basin with the higher thunderstorm threat shifting
westward into the Mat-Su. Weak northerly steering flow comes to an
end, which will result in stationary storms and little
propagation or movement of any storms that do develop.


&&


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

A ridge has built over Southwestern Alaska, promoting a weak
northerly flow into the area. Upper-level support may provide
enough energy to allow for some isolated thunderstorms to generate
in the foothills of the Western Alaska Range and may move
southwest into the Lower Kuskokwim Valley and Bristol Bay by
Saturday. A low has stalled in the North Pacific south of Adak,
pushing gusty southerly winds and light rain across the Central
Aleutians. This will continue to bring rounds of rain showers and
small craft winds to the Western/Central Aleutians through the end
of the week. By Sunday afternoon, a similar convective pattern
may set up in the eastern portions of Bristol Bay and the Lower
Kuskokwim Valley. There is potential for Sunday to be another
active convective day across eastern Southwest Alaska. The focus
will be on how strong offshore flow will warm the area and advect
the cells downstream off the foothills of the Western Alaska
Range. Southwest Alaska will remain is this patten through the
weekend and potentially into midweek next week.

&&


.LONG TERM FORECAST (Days 4 through 7) Monday through Thursday...

A very active pattern on the Alaska Weather map as an upper level
Arctic low spreads its influence across the North Slope into
Interior Alaska through Thursday. A ridge remains across the
Southern Interior, being squeezed between the Arctic low and a
broad low stretching across the Aleutians and Gulf of Alaska
through the period. This ridge is sufficient enough to support
thermal surface troughs and raises the chances for convective
activity. A number of weak perturbations are expected to slide
through the pattern across the Southern portions of the state
throughout the forecast.

Most of the concentrated weather remains in the North Pacific to
the South of the Aleutians and Alaska Peninsula. Showers and
locally breezy conditions begin in the Central and Eastern
Aleutians and the Bering up to the Pribilofs beginning Monday.
Winds taper off late Monday. Showers will occur across the
Southcentral Interior for late Monday. The Aleutians front
continues its Eastward push over the Alaska Peninsula and Kodiak
Island before spreading more rain over Southcentral, Prince
William Sound and the Copper River Valley through midweek. Showers
linger behind the front over the Aleutians and Bering.
Temperatures range from the 40s across the Aleutians warming
across the Mainland into the 70s and possible low 80s over the
Eastern Interior through the period. Thunderstorms are possible
over most of the Eastern inland areas.


- Kutz

&&

.AVIATION...

PANC...Isolated to scattered showers and thunderstorms are expected
to develop near the Talkeetna Mountains late this afternoon and
advect southward along/near Knik Arm. However, with more stable
air over Cook Inlet, expect convection to diminish as it continues
southward. The most likely impact for the terminal is some debris
clouds in the mid to upper levels, with any ceiling that forms
safely in the VFR category. There could be some brief gusts out
of S-SW in the inflow into the convection, but winds will mostly
stay light. Saturday looks like a repeat, with mostly clear skies
for much of the day, then showers and thunderstorms drifting south
from the Mat-Su later in the day. Generally expect more convection
saturday, with a somewhat better chance that a high-based shower
or thunderstorm reaches the vicinity of PANC.

&&


$$