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FXAK67 PAJK 222300
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
200 PM AKST Wed Jan 22 2025

.SHORT TERM...Early this morning a weak atmospheric river moved
across the Panhandle, with the highest values of IVT in the south.
24-hour rainfall amounts remained below 3 inches and snow levels
were above most communities; the exception being the highways
where they were snow covered. A low is currently tracking towards
the northern coast which will drive heavy rain showers at times,
with the potential for some thunder from Cross Sound west. Expect
periods of rain showers and drizzle for the rest of the panhandle
with some light snow along the highways. Thursday a stout high
pressure will build across the gulf, steering active weather and a
moderate atmospheric river towards south-central Alaska.

Snow for the water year continues to be below normal, with Snow
Water Equivalent (SWE) data from the National Water and Climate
Center indicating the current snowpack sitting at 62% of median
for the central and northern Panhandle.

.LONG TERM.../Thursday into next week/...Very little changes made
to Friday and Saturday, with some minor changes made to Sunday
into next week. Still looking at a stout high pressure in the gulf
for this time of year, but with somewhat decreased wind speeds
near the gulf coast compared to prior forecast. Yakutat still
appears to receive the bulk of the precip when the ridge aloft
begins to break down this weekend.

For Friday and the weekend, a blocking pattern continues, with an
unseasonable high pressure in the gulf. This will bring somewhat clearing
skies, downward motion aloft, and lighter winds for the inner
waters. May see some increased winds, particularly in Lynn Canal
as the ridge breaks down aloft. From SW winds aloft, cross barrier
flow over the mountains looks to bring some leeside troughing near
Haines and Skagway, encouraging moderate breezes in Lynn Canal.


Upstream, however, has very cold arctic air advecting down from
the Arctic, which will assist in both strong systems moving into
the northern Gulf Coast, and pushing the stream of moisture
towards the NE Gulf Coast/Yakutat area. It does indeed to look
that the ridge will win over the cold air advection moving in from
the north for at least another day. Main moisture transport, with
significant spread, has the general consensus that Yakutat will
see heavy rain by late in the weekend. Beyond the weekend;
however, cold air will indeed push the ridge to the east, moving
SE AK back into an active pattern, but this time with much colder
temperatures aloft compared to now. Sufficed to say, a pattern
change is in the works.

&&

.AVIATION...With the heaviest precipitation and source of LLWS
moving off to the south and east of the panhandle, post frontal
showers with onshore flow will be the main headache Wednesday
night into Thursday. The NE gulf could see some isolated
thunderstorms Wednesday night from a fast moving short wave
trough. Otherwise expect widespread MVFR conditions over the
panhandle primarily due to lower CIGs, with possibility to drop
to IFR with any locally heavier showers.

&&

.MARINE...Gulf: Swell diminishes this evening, remaining from the
west, as a series of storms impacts the AK peninsula towards
Prince William Sound. As a high pressure builds in the eastern gulf,
expect northwesterly strong breezes along the coast, with the
highest winds from Cape Fairweather south towards Cape Ommaney.
Main wave energy continues to be west-southwest with heights
dropping below 12 ft through Friday. Expect heights to increase
past 15ft along the northern coast Saturday.

Inner channels: A high pressure builds in the gulf through the
end of the week, expect onshore flow, with fresh to strong breezes
the main focus for inner channels. West to southerly winds from
Frederick Sound north to Lynn Canal, and west to northerly winds
building in Sumner Strait south through Clarence Strait.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-013-021-022-053-641>644-651-652-
     661>664-671-672.

&&

$$

SHORT TERM...AP
LONG TERM....NC
AVIATION...STJ
MARINE...AP

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