289
FXAK67 PAJK 312314
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
314 PM AKDT Mon Aug 31 2026

.SYNOPSIS...

Key Messages:

- A low moves SE through the eastern gulf through Tuesday,
  bringing persist rain over the panhandle and scattered to
  isolated thunderstorms along the coast.

- Strong marine wind gusts up to 35 kts possible within N Canal to
  Taiya Inlet this evening.

- Ridging moves into the Gulf midweek, bringing clearing skies and
  warming temperatures through the end of the week.


&&

.SHORT TERM.../Through Wednesday night/ Thunderstorm activity has
been rather vigorous for SE AK standards along the outer coast
from Baranof Island Northwestward. There are two main areas of
convection that we are watching. The first is with the frontal
bands that are moving into the outer coast from Yakutat
Southeastward. Most of the lightning with this feature has been
when the stronger showers impact the terrain along the outer
coast. Some cells have shown lightning rates of 20 to 30 strikes
in a 15 min period. We have not observed any lightning reaching
into the inner channels yet. the second area is centered around
Middleton Island W of Cape Suckling associated with the main area
of low pressure diving SE from Prince William Sound. This low has
a decent amount of vorticity associated with it and the low itself
is displaying cold core characteristics with 850 mb temps in the
core of the low as low as -1C. Over the warm waters of the gulf
this is producing a good amount of thunderstorms. These two areas
of thunderstorm potential will be the main driver of the forecast
tonight into Tuesday as the front over the eastern gulf pushes
east and the low near Middleton dives SE through the eastern gulf.
A wide area of scattered to isolated thunderstorms has been
included in the Gulf waters marine and outer coast public
forecasts through Tuesday at least with most of the thunderstorm
activity staying along the outer coast and near the low center. I
can not completely rule out an isolated thunderstorm or two making
it into the inner channels tonight from Glacier Bay and Lynn
Canal, southward to Clarence Strait. So the area of slight chance
thunderstorms extends into those areas as well tonight. Some of
these storms could produce some gusty winds up to 30 kt,
lightning, and maybe some brief small hail as they move through.

Otherwise, Rain with some breezy conditions are the rule of the
day. Northern inner channel winds have reached 20 kt (with 25 kt
in Lynn Canal) with gusts reaching 30 kt in some areas. Highest
expected winds will be this evening before diminishing overnight
and then switching to the north early Tuesday as the low in the
gulf slides SE. The northerly winds are expected to peak around 15
to 25 kt in Lynn Canal Tuesday night into Wednesday morning. The
rain will also be on a diminishing trend from NW to SE into
Tuesday especially as overall flow turns more offshore on Tuesday.
Some larger breaks in the cloud cover are also expected to start
developing first across the north on Tuesday and becoming more
widespread with the drier weather into Wednesday.

.LONG TERM.../Thursday through Sunday/...The long term forecast
remains largely uneventful as an area of ridging persists over
the gulf through Saturday, bringing northwesterly flow, drier
conditions, and warmer temperatures through the second half of the
week. The whole panhandle will see clear skies through Friday,
with cloud cover moving in from the north starting Saturday.
Northerly winds will increase up to 25 mph overnight Wednesday and
through Thursday. Winds will decrease again overnight into Friday
morning before the flow switches southerly through the afternoon
as the pressure gradient turns. Through the weekend, southerly
winds in Lynn Canal will increase to around 20 kts with the help
of sea breezes through midday. Other communities should also feel
local sea breezes increase midday. High temperatures will reach
the high 60s to low 70s in the northern panhandle and into the 70s
in the southern panhandle Thursday and Friday with ample
clearing. Some areas in the southern panhandle are looking like
they may reach the upper 70s Friday and Saturday, mainly Hyder, so
will continue to watch that through the week. Models are still in
disagreement going into the weekend, with the EC holding onto the
ridge in the gulf and the GFS favoring an upper level shortwave
making it over the ridge and into the northern panhandle
midweekend. Including a chance for rainfall in the northern
panhandle through Saturday evening, increasing into Sunday.
Depending on how things change over the next few days, we could
have a very dry or very wet weekend.

&&

.AVIATION...  A low pressure system and cold front is moving through
the Northern Alaska Panhandle this afternoon. This system has
produced thunderstorms today, including for Yakutat, Pelican, and
Sitka. Through tonight, the highest thunderstorm chances look to be
along mountains, but thunderstorms are possible this evening for
Yakutat, Sitka, Gustavus and Juneau.

As the system brings showers and rumbles of thunder, it is expected
to bring MVFR ceilings, with IFR ceilings tonight for areas south of
Fredrick Sound. For the Northern Panhandle conditions are expected
to improve by the end of the TAF period. Behind the front, fog is
possible tonight for Yakutat and along the Chilkat.  The strongest
winds today are expected for Skagway. Behind the front Tuesday,
winds out of the north are expected for the Northern Panhandle and
improve flight conditions to VFR. The Southern Panhandle looks to
stay with ceilings AoB 2500 feet through 00Z Wednesday.

&&

.MARINE...

Outer waters: Kept large portions of the ongoing forecast, as
current forecast has successfully represented realty well, and is
closely aligned with current thoughts going forward. The strong
low pressure system driving much of the current weather and the
weather through Tuesday night is expected to traverse down the
gulf coast tonight. West of Prince of Wales Island, it will arrive
during the morning hours of Tuesday, before moving near Haida
Gwaii Tuesday night. Two convective fronts are associated with
this low: the first is moving over the panhandle near Sitka at
time of writing, and will continue to progress eastward over the
panhandle before weakening. Thunderstorms (40-50%) are possible
particularly along the gulf coast, along the windward side of
mountains. Frequent lightning has been observed with these storms
along with heavy rain and a small chance for stronger cells with
small hail, which may reduce visibility. Still expecting a fresh
jolt of westerly swell as well, primarily collected with the
highest wind speeds, with westerly swell of around 7 ft increasing
to 11 ft for combined wave height of 14-15 ft Monday evening into
Tuesday. Wednesday sees a ramp of northwesterlies along the outer
coast, driven by rising pressure, and the strong low departing to
the south.

Inside Waters: Kept large portions of the ongoing forecast, as
current forecast has successfully represented realty well, and is
closely aligned with current thoughts going forward. Still
expecting a northerly shift beginning in Lynn Canal and Glacier
Bay from an approaching cold front from the north. Expecting a
slow ramp up Tuesday morning, maximizing to 25 knots with gusts up
to 35kt in Lynn Canal and up to 15 knots elsewhere. As for
thunderstorm development, expanded out chances for thunderstorms
clear into southern Lynn and southward. Highest chances for the
Icy Strait area are ongoing into the evening, with chances
shifting south through the night until reaching the Clarence
Strait area Tuesday morning, as the low moves south. For the
central panhandle, winds overnight will transition to mainly
easterly before fully committing to northerly, driven by the
strong surface low moving south. Currently expecting the broad
northerly trend to continue through at least Thursday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-013-022-031-641>644-651-661>664-
     671-672.

&&

$$

SHORT TERM...EAL
LONG TERM...ZTK
AVIATION...Musall
MARINE...Compton

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