602
FXAK68 PAFC 140100
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
500 PM AKDT Thu Jun 13 2024

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

Easterly wave activity into Southcentral comes to an end on
Thursday, at least for the next few days. A low over the Gulf of
Alaska will push eastward and along the coast of British Columbia
through Friday. A second low lifting into the Western Aleutians is
resulting in downstream ridging over the rest of the Bering, with
the ridge forecast to build into western Alaska through Saturday.
Weak northerly flow will prevail across Southcentral Alaska
Friday and Saturday with drier conditions lending to a warming
trend through the weekend. High temperatures in the upper
60s/lower 70s can be expected across Southcentral with the Copper
River Basin seeing temperatures warm into the upper 70s on
Saturday. With the warmer weather Southcentral will see the return
of thunderstorm chances. Weak to moderate instability over the
Copper River Basin will likely see isolated to scattered wet
thunderstorms develop by late afternoon. Some of this activity
will spread southwestward through the evening hours, with
potential for showers to move from the Valley into Anchorage.
While the greatest threat for lightning will exist from the Copper
River Basin into the Susitna Valley, convection will be possible
as far south as the Western Kenai Peninsula.

Northerly flow will begin to transition to southeasterly on
Sunday, which should see the seabreeze return for coastal areas
and mildly cooler temperatures when compared to Saturday.
Regardless, widespread upper 60s to lower 70s temperatures are
forecast on Sunday as well, with another round of wet
thunderstorms possible over the region.

&&


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

High pressure continues to build over Southwest Alaska, leading to
much drier conditions and gradually warming temperatures. 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 near the Western Aleutians pushes
westward, along the southern edge of the Aleutian Chain over the
next few days, stalling in the North Pacific south of Adak. This
will 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
some mild uncertainty regarding the extent of this round of
thunderstorms, namely how strong offshore flow will warm the area
and advect the cells downstream off the foothills of the Western
Alaska Range.

&&


.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... It will remain dry into the evening hours.  A mostly
cloudy sky persists though into the late evening hours. Ceilings
will lower LATER this afternoon but remain in VFR conditions as
winds remain from southerly to southwesterly direction.

&&


$$