799
FXAK68 PAFC 270110
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
510 PM AKDT Wed Jun 26 2024

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

A front associated with an upper Bering low is moving into the
western Gulf and expected to slow substantially as a ridge over
mainland Alaska continues to remain stubbornly in place. South to
southeasterly moisture will keep the potential for low stratus and
fog near the coastlines over the next few days, though confidence
is low on the extent of these low clouds and surface visibility.
Chances for precipitation will increase along the front near
Kodiak for Thursday, but the rain will most likely be brief as the
front weakens Thursday night and Friday morning.

With the upper ridge shifting eastwards, thunderstorms chances
will also shift slightly to the east. Isolated to scattered
thunderstorms are once again possible along the slopes of the
Talkeetna Mountains, the Alaska Range, and the Wrangells; as well
as across much of the Copper River Basin. Thunderstorms have
already initiated over the Talkeetna Range and the eastern Alaska
Range near Paxson and Mentasta Lake. Frequent lightning this
afternoon and evening for those areas will become more isolated to
scattered tonight. CAPE values of between 500 to 1000 J/kg look
to continue through this evening for the Talkeetna Mountains over
to the Wrangells on the southern side of the Alaska Range. While
most of the convection will be more pulse- type, diurnally
driven...higher lightning activity today is due to a weak wave
rounding the upper low combined with another weak easterly
traversing wave rounding the ridge and allowing enough forcing to
get more scattered thunderstorms going over the Talkeetnas.
Thursday will again see the potential for isolated to scattered
storms, but again shifts eastwards into the Copper River Basin.
Thunderstorm activity is expected to become less likely each
afternoon for the later half of this week. Higher chances for
occurrence will be farther to northeast in the Copper River Basin,
along the eastern Alaska Range. Diurnally driven showers will
otherwise continue over most other mountain slopes.

- PP / rux

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA/ALEUTIANS
(Days 1 through 3: Tonight through Saturday)...

Forecast remains on track as the domain transitions into a more
synoptic pattern. Isolated wet thunderstorms are possible mostly
around the Western Alaska Range and far eastern portions of the
Middle Kuskokwim Valley this afternoon and evening.

Cooler and more stable conditions will continue to spread from the
Bering into Southwest Alaska as a result of a strong Bering Sea
low. The surface low and its upper-level counterpart are
currently positioned over the central Bering with its front
lifting across the Kuskokwim Delta and Bristol Bay. Steady rain
and southeasterly gale-force sustained winds,with gusts up to 50
mph, accompany the front. The winds are expected to produce high
surf along the northern Kuskokwim Bay coast (especially the
communities of Kwigillingok and Kongiganak) through early Thursday
morning. Thus, a High Surf Advisory is in effect for the northern
Kuskokwim Bay coast. Waves and surf should peak this afternoon
during high tide, with waves expected to rise 3 to 6 feet above
the normal highest tide line.

The front weakens on Thursday along the Southwest coast as the low
itself slowly drifts into the northern Bering. For Thursday into
Friday, the bulk of the precipitation will be focused along the
southern-facing side of the Kuskokwim Mountains (interior Bristol
Bay) as well as the Kuskokwim Delta coast. On Friday, as this low
continues weakening and tracking towards Russia, another system
traverses the Aleutian Chain and heads towards the AKPen. It is
expected to encompass the eastern Bering Sea on Saturday while it
produces rain showers for western portions of Southwest and also
portions of the Bering.

Fenrich

&&
.LONG TERM FORECAST (Days 4 through 7)...

A ridge will begin to weaken over the Southcentral and Copper
River Basin Sunday. Isolated rain showers or thunderstorms are
possible though into the beginning of next week. An area of low
pressure will form in the Bering Sea and move into the Gulf of
Alaska Tuesday morning bringing precipitation and gusty winds to
Bristol Bay and the Alaskan Peninsula by mid week.

-DJ/DD

&&

.AVIATION...

PANC...VFR conditions will persist through the TAF period, with
light southwesterly up-inlet flow prevailing into Friday.
Building high pressure over the area will also result in decreased
precipitation chances over the terminal.

With little change to the overall weather pattern, it`s likely
that low stratus and/or fog will once again creep up Cook Inlet
and towards the terminal early tomorrow morning, with low
confidence on exact timing.

&&


$$