868
FXAK67 PAJK 180554 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
954 PM AKDT Sun Aug 17 2025

...Evening and 06z Aviation Discussion Update...
No major changes to ongoing forecast this evening as easterly
wave continues to split the panhandle into two regimes, dry across
the south and wet for the north. Areas along and north of the Icy
Strait corridor will continue to see light rain and overcast
skies through Sunday night while the southern panhandle gets a bit
of a break through mid morning Monday. Winds have gradually
diminished over the last few hours, with strongest recent wind ob
courtesy of Eldred Rock up to 22kts. Winds will continue to
diminish through the overnight hours, going near calm and variable
overland. Temperatures tonight expected to drop down into the
upper 40s to mid 50s across the panhandle.

.SHORT TERM.../tonight through Monday night/...
Light rain sticks around for parts of the panhandle as wind
speeds decrease.

Key Messages:
-Easterly wave will keep rain showers over the northern half of
 the panhandle.
-Southern half will have diminishing showers with decreasing
 cloud cover tonight.
-Wind speeds are expected to decrease as the low in the gulf
 weakens and moves away from the panhandle.

Details: General area of low pressure in the gulf will weaken and
slide southward. As it does, the pressure gradient over the
panhandle will lighten up and allow wind speeds to decrease or
remain light/variable tonight with the lighter winds lasting
through Monday night. That being said, Eldred Rock has been
reporting 20 to 30 kt southerly winds today. Wind speeds should
drop below 20 kts later this evening with continued decreasing
winds overnight.

For the rain showers, there are two weather patterns happening
over the area - diurnal pop-up showers in the south and an
easterly wave in the north. The showers in the south will, for the
most part, decrease in number once the sun goes down. Any
exceptions to this will be caused by a rogue shower that drifts in
from south of the panhandle but they wouldn`t last long.
Otherwise, skies will be clearer and an overall quiet night with
the quiet weather lasting into Monday.

For the northern showers, these are coming from an easterly wave
that is bringing the moisture in from Canada. A reinforcing 500mb
vort max will keep high the PoPS in place until around 10AM to
Noon Monday. That`s when the showers look to really decrease with
the drier weather lasting through Tuesday morning. A few showers
are possible mainly along the coast on Tuesday, before those
chances move inland later in the day.

.LONG TERM.../Into next weekend/...
Overall drying trend late this week with warmer temps likely for
the later half of the week.

Key Messages:
-Lingering low pressure passing to the south will give some rain
 and rain shower chances mid-week. 24 hour rain amounts will be
 light.

-A building ridge of high pressure afterwards will bring drier weather
 and warmer temps for the later part of the week into next
 weekend.

-Marine wind speeds look to be on the lighter side next week at
 around 5 to 10 knots with some isolated trouble spots getting up
 to 15 knots due to afternoon sea breeze enhancement.

Discussion: A passing area of low pressure will keep at least
some rain chances over the panhandle mid-week. Greatest PoPS are
in the south with lower PoPS in the central and northern
panhandle. Rain amounts look to be light due to the spotty nature
of the showers.

After the lingering low finally moves on and out of the area mid-
week, a potential ridge of high pressure looks to move in. This
would bring decreasing rain chances and decreasing cloud cover. So
sunnier skies are looking likely later next week. With sunnier
skies comes warmer temps, with highs warming to the upper 60s to
the near 70 for Thursday into next weekend.

&&

.AVIATION.../Until 06 Tuesday/
Easterly wave continues to split the panhandle in two with rain
and predominant MVFR to IFR flight conditions for the northern
panhandle along and north of Icy Strait with CIGS AoB 2500ft and
intermittent reduced visbys down to 3SM. For the central and
southern panhandle, Sitka over to Petersburg and southward, VFR
conditions prevail with CIGS AoB 8000ft with general 5 to 6SM
visbys.

Through the rest of Sunday night, anticipating this split regime
and northern panhandle rain to continue with MVFR or worse flight
conditions for TAF sites along and north of the Icy Strait
corridor with CIGS lowering AoB 2500ft by 12z Monday. Gradual
improving conditions across the northern panhandle through Monday
afternoon, gradually improving to low-end VFR by 03z Tuesday as
rain diminishes. For the southern panhandle, expecting VFR
conditions to prevail through the TAF period, with small chance of
MVFR ceilings early morning Monday.

High forecast confidence of winds should remain 10kts or less
through tonight, going near calm and variable through 12z into
Monday morning. No LLWS concerns through the period.

&&

.MARINE...
Synopsis: A weakening low pushes northwestward through the
eastern Gulf of Alaska, sending periods of showers and gusty winds
into the Inner Channels through the latter half of the weekend.

Inside Waters: Winds up to strong breeze (22 to 27 knots) moving
from Clarence Strait northward through tonight with some gusts up
to 25 knots possible, reaching southern Stephens Passage Sunday
morning. On Sunday, the low center will continue to propagate
westward before rotating southward out into the Gulf of Alaska,
weakening further and allowing winds across the inner channels to
relax down to gentle or moderate breeze (7 to 16 knots) late
Sunday.

Outside Waters: For tonight, Small Craft Advisories are posted
for winds increasing to 25 kts and seas around 10 ft from Dixon
Entrance north to Cape Decision offshore about 50 nm, where the
tighter pressure gradient is on the east side of the main area of
low pressure. As the main area of low pressure moves to the
northwest across the eastern Gulf, we do expect to see the areas
of tighter pressure gradient shifting north from Cape Decision to
Icy Cape and out 85 nautical miles through Sunday...with winds at
times 25 to 30 kts sustained. As the low pressure system weakens,
we expect winds and seas to diminish over the eastern Gulf by
Monday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

UPDATE...NM
SHORT TERM...GJS
LONG TERM...Ferrin
AVIATION...NM
MARINE...Ferrin

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