Gale Warning 537, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
514 PM AKDT Fri Aug 16 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3/Today
through Sunday night)...

A rinse and repeat pattern is in store for Southcentral over the
weekend. A shortwave ridge is currently building in from the west
as another moderately strong system pushes warm air north and
builds heights. This will lead to mostly calm conditions for
Saturday, with pockets of sunshine throughout the region. On
Sunday the trough axis will shift east towards the AlCan border,
placing the region back into Southwest flow. In similar fashion to
conditions Thursday and Friday, periods of light rain will spread
over Cook Inlet and the Mat-Su through the day, while more
sustained rain is expected from Talkeetna north. Eventually, the
upper level trough will move east, with the southern edge of the
trough axis and vorticity max spreading over the aforementioned
areas. This will be the most likely period for rain (Sunday
afternoon/evening) as winds also pick up through the typical gap
locations. The trough will then slide east, bringing another
shortwave ridge over the area starting late Monday.

-Jones

&&

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

A Coastal Flood Advisory remains in effect through 11 pm Sunday
for the Kuskokwim Delta including the cities of Kongiganak,
Kwigillingok and Kipnuk as water levels will rise as high as 3 to
6 feet above normal highest tide impacting low lying areas along
the coast.

A Flood Advisory remains in effect for the Kuskokwim River at
Bethel until 1:00pm Sunday because of flooding caused by a
combination of excessive rainfall across the Kuskokwim Valley and
storm surge backing up into the Kuskokwim River.

Two Bering Sea lows merged into one this afternoon and will bring
gusty winds and moderate precipitation to the region through
Sunday evening. Earlier this afternoon, satellite showed the
merging of the two storms, one located just west of Shemya and the
other southwest of Amchitka, into one new located north of
Amchitka. The storm's front stretches across the Aleutians and
into Southwest Alaska where periods of rain and gusty winds have
occurred. Though a few hundredths of an inch of rainfall have
fallen the past six hours and wind gusts ranging from 35 to 45 mph
were widespread this morning, the rain has ended and wind gusts
diminished greatly across most of the area this afternoon.
Southerly wind gusts from 35 to 45 mph in the Central and Eastern
Aleutians will continue to persist through this evening. Also,
areas of patchy fog was common across the Mainland and the
Western Aleutians. Fog return over the weekend in coastal
locations, the Pribilofs and most of the Aleutians.

As the merged low remains fairly stationary into tomorrow
morning, a southwesterly wind direction will dominate across the
Aleutians, Southwest AK coastline and AK Pen. Therefore, wind
gusts will likely be highest on the southern side of the
Aleutians, through the Aleutian gap areas and along the Kuskokwim
Delta coast. Wind gusts in these areas are likely to range between
50 and 60 mph with an isolated gap wind gust above 60 mph in the
Central Aleutians through this evening. Gale warnings are in
effect.

Tomorrow, the low migrates in a southeasterly direction toward
the Pribilof Islands reaching the mainland Sunday evening. Frequent
waves of moderate precipitation are likely this weekend across
the Mainland ahead of the low. The first wave of precipitation
from this evening into tomorrow morning is likely to fall from
Kipnuk to Bethel northward. Rainfall amounts ranging from 0.5" to
1.0" are likely. The greatest chance of steady precipitation
Saturday evening into Sunday afternoon is from Bethel southward to
the AK Peninsula west to Cold Bay when rainfall amounts ranging
from 0.25" to 0.50" are likely.

-DJ

&&
.LONG TERM FORECAST (Days 4 through 7/Tuesday through
Friday)...

A series of lows will bring significant weather to Alaska for the
period. Models are in agreement on the paths these lows will
take. The first low will continue to move through Alaska over the
weekend until it weakens and exits north of the Bering Sea on
Monday. Winds will weaken in the Central and Eastern Bering as
this low exits the region. Locally heavy rains will remain for the
Southcentral interior on Monday due to a lingering trough from
the low. After a break in activity, The second low, the remnant
low from Tropical Storm Ampil, will move across the Western
Aleutians on Monday night. This system will move into the Seward
Peninsula region by Thursday, but will fill as it travels.
Nevertheless, locally heavy rains will accompany this system over
the Central Aleutians and Bering Sea through Thursday. Near gale
force winds are possible with this system between the Western
Aleutians and St. Lawrence Island through Wednesday. The western
coast of Alaska will be affected by these winds from late Tuesday
through Thursday. Upper level ridging will be persist along the
Gulf of Alaska through Thursday morning before giving way to a
shortwave trough that will develop across South Central Alaska and
Prince William Sound on Friday. Conditions will improve in the
western Aleutian region as the system moves north with winds
slowly weakening.

-DD

&&

.AVIATION...

PANC...Southeasterly winds out of Turnagain Arm are expected to
persist into Friday afternoon and then begin to subside. The rain
moving over the terminal overnight is not expected to lower
ceilings and visibilities too much. Most likely limitation is for
the ceiling to lower near or to MVFR levels after midnight into
the early morning hours. Otherwise VFR conditions are expected.

&&