Sitka, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

975
FXAK67 PAJK 141745
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
945 AM AKDT Wed May 14 2025

.UPDATE... Aviation 18z updated discussion.

&&

.SHORT TERM...A couple changes to the ongoing short term forecast,
but changes overall are minor and do not change the ongoing
message: Wednesday morning is the break before the front moving in
Wednesday night. Main changes are related to PoP, with the next
upcoming frontal band to be slightly slower than anticipated, due
to the current ridge over the panhandle being slightly more
robust. Furthermore, run to run trends in deterministic CAMs show
that the warm occlusion struggles to push past the coast
mountains, meaning that a majority of the precipitation will be
localized to the outer coast and southern panhandle. Now, this is
not to say that only these locations will see rain, as the
southeast to south orientation of the moisture flow aloft shows
that even places in the northern panhandle will get accumulating
precipitation. Rather, a bulk of the QPF will be directed at the
southern panhandle and outer coast.


.LONG TERM...By Thursday morning a respectable low will be
enveloping the Gulf of Alaska, with southeasterly gale force winds
expected. Mariners navigating our waters should use caution,
especially in the vicinity of Prince of Wales and Southern
Clarence. Here the long fetch from Dixon Entrance/Hecate Strait
will drive fresh, short period seas of 8 to 10+ ft out of the
south southeast. Winds reach their peak speed Thursday morning,
diminishing later Thursday evening. Friday a broad Rossby wave
will be organizing and moving south and east from the Bering Sea,
serving as the parent system to a developing surface low ejecting
into the Gulf of Alaska. Simultaneously a ridge will slide across
the over the Panhandle into Saturday driving some drier weather
and lighter winds for the evening and into Sunday. While not as
energetic as Wednesdays system, expecting some onshore flow and
shower activity to return later Sunday/Monday as cyclogenesis
occurs in the western gulf. Divergence in agreement between model
guidance in position and depth of the associated surface low is
resulting in a few different wind solutions for our coast, but
buy-and-large expect south-southeast flow below gale force.

&&

.AVIATION...Aviation concerns grow through the day and overnight
into Thursday morning as an approaching storm brings the threat of
wind shear and lower CIGS/VSBY. We remain consistent on CIGS/VSBY
diminishing to MVFR later Wednesday evening as moisture moves in,
with the heaviest rainfall and worst conditions south of
Frederick Sound and along the coast. Touching on LLWS, most of
the Panhandle will experience bumpy conditions through Thursday
but the main threat for LLWS remains in the southern Panhandle,
with 30 to 40 knots of wind at or above 2,000ft. Expect peak
winds Thursday morning to persist into the afternoon.

&&

.MARINE...Eastern Gulf of Alaska...Fairly quiet weather in the gulf during
the morning hours today, with light air to light breezes
throughout the eastern gulf. This will be the short transitionary
period between the prior W flow, and the switch to SE later in the
morning. SE winds will increase throughout the day, maximizing in
the evening with near gale to gale force winds along the NE to E
coastline. Highest wind speeds are along the NE gulf coast, with
areas next cape Suckling exceeding 35 knots. Similar with
waveheights, seas will build to between 10-16 ft with higher
amounts near Cape Suckling, during roughly the same period of time
as the front.

Inside waters...Light air in the inner waters with the exception
of northern Lynn Canal, due to a tight but relaxing gradient in
the northern panhandle. Expect deteriorating conditions beginning
in the afternoon. Expect for wind speeds to pick up in Chatham
Strait first, and expand eastward by the evening. As a mesoscale
feature moves up from the south, wind speeds will increasingly
become easterly in nature, with Peril Strait, Fredrick Sound, and
Icy Strait being the highlights. One certainty with this forecast
as how far the winds will extend into Stephens Passage, which will
change depending on how far the additional mesoscale feature will
move northward. Not expecting any sustained winds above a strong
breeze, except out of ocean entrances



&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale Warning for PKZ652-664-671-672.
     Small Craft Advisory for PKZ035-036-053-641>644-651-661>663.

&&

$$

SHORT TERM...GJS/NC
LONG TERM....EAB/AP
AVIATION...AP
MARINE...GJS/NC

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