363
FXAK68 PAFC 111255
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
455 AM AKDT Tue Jun 11 2024

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

The low that has been lingering in the western Gulf is continuing
to gradually weaken and slowly nudging its way east over the next
couple days. High pressure over the northern interior of Alaska
is helping to flatten the flow and allowing for most of the flow
east to west. Widespread cloudiness and increasing chances for
showers over the next couple days will keep the temperatures more
cool and mild. Surface winds are predominately from the south to
southeast and gap flows are expected to return to Turnagain Arm,
Knik River, and Copper River Valley, but is not expected to be a
strong as the previous few afternoons.

The nature of the easterly waves and pop up showers makes this
forecast more challenging to determine exactly where and how much
rainfall will occur. Generally though, showers along the coast are
expected to gradually lift today and spread across the Copper
River Basin early. A few small, quick moving showers have
developed off the foothills of the western Chugach through Sutton
into the Matanuska Valley and also Anchorage and the western Kenai
Peninsula. Chances will increase throughout the day and move from
east to west under the prevailing flow. Models are not capturing
the progression and precipitation amounts very well, but the
general pattern points westward, spreading rainfall into the
Susitna Valley later this afternoon. A similar set up is expected
for Wednesday as well. Thursday, precipitation chances decrease
and the weather will begin to trend towards a warmer and drier
(and perhaps more convective) weather will continue through the
later half of the week and through the weekend.

rux

&&


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

Winds have diminished overnight across Bristol Bay as the pressure
gradient across Southwest Alaska weakens. Broad low pressures sits
in south of the Alaska Peninsula, cycling weak shortwaves over
Southwest and south towards the Eastern Aleutians. Conditions will
be mostly dry, however, there will be periods of light rain
showers today and tonight as well as a chance for some wet
thunderstorms in western Bristol Bay and along the Western Alaska
Range. High pressure builds in the over the western Bering Sea and
will progress eastward over the next several days. A low
developing west of the Western Aleutians will push south of the
Aleutian Chain mid-to-late week, eventually stalling in the North
Pacific south of Adak. This will bring rounds of rain showers and
small craft winds to the Western/Central Aleutians Wednesday
through the end of the week.

&&


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

High pressure looks to continue for the interior of the state
while much of the Bering Sea, North Pacific, and Gulf of Alaska
will remain under the influence of low pressure. This pattern will
continue to promote dry and warm weather inland with cool and
showery conditions for the Gulf coast, Aleutian Chain, and Alaska
Peninsula. There are still some questions in how each of these
pressure cells orients themselves throughout the long-term. No one
period looks to be a washout, rather there can be transient
periods of drier weather between shortwaves moving through the
flow along the Gulf and Aleutian Chain. While there is very
general agreement with the synoptic pattern, there are plenty of
disagreements with placement and track of mesoscale shortwaves
embedded within the synoptic flow.

&&

.AVIATION...

PANC...Light rain is possible through the early afternoon with a
passing easterly shortwave. With any rain, there is a moderate
chance of ceilings below 5000 ft and a low chance for MVFR
ceilings. This afternoon, gusty southeasterly Turnagain Arm winds
return to the terminal, peaking in the 20 to 30 knot range as ceilings
lift above 5000 ft. Winds weaken and shift out of the south with
up-inlet flow in the late evening to near midnight timeframe. Rain
returns on Wednesday, bringing greater chances for MVFR ceilings.

Quesada

&&


$$