510
FXAK68 PAFC 231303
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
503 AM AKDT Thu May 23 2024

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

Cool, cloudy, and rainy weather will give way to drier and somewhat
warmer weather on Thursday for much of southcentral Alaska. As of
5am, radar shows light shower activity remains in place from about
the Mat-Su Valley southwards through Anchorage and the Kenai
Peninsula. This will taper off this morning as the associated low
and parent upper-trough shift east. The exception to this drier
weather will be for the Copper River Basin, where precipitation will
linger through the day, particularly north and east of Glennallen.
Snow may be seen as low as 2000 feet, with some light accumulation
possible towards Mentasta and Isabel passes. In fact, as of 5am,
snow is being reported along the Glenn highway at Eureka.

The drier conditions and breaks of sunshine will be short-lived,
however, as a low tracking into southern Alaska from the Bering Sea
will bring cloudier conditions and another round of precipitation to
Southcentral. Rain chances return for much of the area on Friday,
though the heaviest, most persistent precipitation will occur along
the north Gulf coast. A front lingers along the coast, keeping these
areas wet through Saturday. Further inland, a shift to northerly
flow as the low tracks into the Gulf will lead to some drying and
breaks in the clouds heading into the weekend.

-Brown

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA AND THE
ALEUTIANS (Days 1 through 3)...

Below normal temperatures will continue across the Bering and
Southwest Alaska as yet another occluded low tracks through the
region the next few days. Ahead of the low, its front will push
inland of the Southwest coast later today with increasing showers
expected. While precipitation should consist of rain for most
areas, Mekoryuk will likely see a period of snow through midday,
eventually transitioning to a rain/snow mix or all rain as
afternoon temperatures increase into the upper 30s. Windy
conditions are forecast along the Aleutian Chain as multiple
shortwaves traverse the base of the low. Widespread small craft
winds gusting to gale force will move from the Central Aleutians
during the day to the Eastern Aleutians later tonight.

Friday will see showery conditions continue for Southwest while
west to northwest winds shift over the Alaska Peninsula. Nikolski
to Akutan will see the strongest winds on Friday before low
pressure slides into the Gulf of Alaska and brief high pressure
sets in over the Bering on Saturday. Precipitation begins to clear
out behind the low with northerly flow becoming prominent across
the Bering Saturday morning.

-BL


&&

.LONG TERM FORECAST (Days 4 through 7) Sunday through Wednesday...

A steadily weakening upper level low slips across the Southern
Gulf of Alaska through midweek. A somewhat energetic low in
Northwest Alaska transits along the West coast and weakens through
the period. A moderate amplitude ridge in the Western Bering
flattens out as it moves along the Aleutians by late Monday. Some
additional energy moves in with a weak upper low pushing over the
Aleutians through Wednesday. Model confidence starts off good in
GFS/ECMWF blends and run-to-run consistency, before making the
switch to deterministic guidance by midweek. Aside of showery
precipitation along the West Coast with the low moving Southward,
the bulk of the active weather will come with the surface lows and
fronts or troughs over the Southern portions of the state. Areas
of rain spread over the Gulf and Southcentral, diminishing through
Wednesday. Brief periods of locally heavy rainfall starts over
the Western Aleutians and Bering Sunday, moving Eastward into
Southwest Alaska, and across the AKPEN and Kodiak Island by the
end of the forecast midweek. The next system starts to repeat the
weather pattern in the West for Wednesday.


- Kutz

&&

.AVIATION...

PANC...Low stratus this morning should begin to lift/dissipate
later this morning, then clear out entirely as high pressure
builds in from the west. Turnagain arm winds are not expected to
develop this afternoon, but there could be a slight uptick in
winds out of the west- southwest with the sea breeze this
afternoon and evening. Otherwise, VFR conditions and light winds
will persist through tonight.

&&


$$