683
FXAK67 PAJK 240621 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
1021 PM AKDT Sun Aug 23 2026

.UPDATE...For 06z TAF Issuance.

&&

.AVIATION...Southern panhandle remains the main source of
aviation problems as heavy rain and increasing winds will
continue overnight into early Monday morning. The primary
concerns will be lowered VIS due to heavier rain as well as CIGs
dropping to AoB 1000 ft, with periods of LIFR conditions expected
from Wrangell and Petersburg southwards before improvement later
in the morning Monday. Despite some improvement, MVFR and IFR
conditions will still be rather widespread south of Sumner Strait.
North of Frederick Sound, offshore flow has provided generally
VFR conditions and this should continue into Monday morning before
rain gradually spreads northward with a chance to bring MVFR
conditions. Patchy fog is possible around Yakutat through the
early morning hours depending on if higher clouds clear out.

Only significant surface winds are also expected down in the
southern panhandle still, with gusts up to around 25 kt as of this
discussion. Strongest winds are expected between 6z and 12z over
the far southern panhandle, with gusty winds near Dixon Entrance
and up into Misty Fjords. Some speed shear is likely overnight
over southern Clarence as southeasterly winds progressively
increase from the surface up to 2000 ft ASL. Wind conditions
improve into Monday as the main winds from the system move into
Canada.

&&

.PREV DISCUSSION......ISSUED AT...346 PM AKDT Sun Aug 23 2026

SYNOPSIS...

Key Messages:

- An atmospheric river moves into the southern panhandle Sunday
  evening, bringing moderate rain and periods of heavy rain.

- Clearing for the northern half of the panhandle by Monday
  afternoon. More breaks in the clouds on Tuesday.

- Onshore flow continues through Wednesday and Thursday, with
  continued rain chances. More clearing possible Friday.

SHORT TERM...Main area of interest continues to be the
atmospheric river moving into the southern panhandle, primarily
impacting Ketchikan, Metlakatla, and Misty Fjords. Satellite
imagery of incoming moisture continue to show stout precipitable
water of around 1.2 inches. This combined with estimated aloft
winds shows IVT values exceeding 500 kg/ms. This plume, along with
freezing levels exceeding 10000 ft, is expected to bring a
majority of the heavy rain for the aforementioned areas. The warm
front associated with this system is currently around the Kake
area, and is expected to stall, as the stronger shortwave wraps
around the upper level parent low in the gulf. Main changes to the
forecast is the tightening up of heaviest rainfall, now primarily
between 4 PM today and 4 AM tomorrow morning. A secondary
shortwave is starting to look increasingly likely, moving up from
the south along Dixon Entrance Monday into Monday night. Currently
have this as moderate rain, but could see pocket of heavy rain,
particularly for Metlakatla.

Another change is how far the strong shortwave tonight will push
northward on Monday. Confidence has increased that most areas will
at least see some rainfall, including in Haines and Skagway during
the morning to early afternoon hours. Not expecting a large
impact, as a majority of the moisture will be drained as it moves
northward, as well as the waves losing upper level support.

Rain amounts are mostly unchanged through Monday afternoon,
although the secondary wave will need to be monitored closely to
adjust. From the previous discussion: likely to see around 2.5 to
3.5 inches of rain in 24 hours, with isolated areas seeing up to
or more than 4 inches. There is even a slight chance for the
aforementioned areas to see those higher rates to around 4 inches
in 24 hours.

LONG TERM.../Wednesday through Saturday/... A broad upper-level
trough continues to make its way across the panhandle Wednesday
and Thursday, which is likely to drive an active, wetter pattern
through the middle of the week. Low level troughing, that looks
to build off of western Alaska, and the moisture associated with
it push eastward across the gulf early Wednesday morning which is
expected to bring wide spread rain to the panhandle on Wednesday
afternoon. Rain is likely to last through most of the day on
Thursday before the main frontal boundary shifts east. There is a
chance for an area of high pressure to build sometime early in the
day Friday which could bring a brief period of clearing,
especially over the northern panhandle. Confidence in rain
chances then increases later in the day on Friday as another front
approaches the panhandle from across the the gulf. Rain is
expected to persist through the rest of the period. Rain
accumulations through the period are expected to be light to
moderate, with coastal locations likely to receive higher
rainfall totals. Temperatures are likely to be in the upper 50s to
60s with low diurnal ranges due to constant cloud cover.

AVIATION...Southern panhandle is the main source of aviation
problems tonight. A wet front will be bringing mainly low vis and
ceilings for many areas due to rain from Frederick Sound
southward. Lowest conditions will be over the Wrangell, Ketchikan,
Misty Fjords, and Annette Island area overnight with vis as low
as 2 to 3 miles and ceilings down to 500 to 1000 ft. There might
be a little improvement Monday but MVFR and IFR conditions will
still be rather widespread south of Sumner Strait. Farther north,
more offshore flow will cause conditions to improve the farther N
and W you go tonight into Monday. VFR conditions will be more
likely encountered north of Frederick Sound and skies will likely
have significant breaks in the cloud cover NW of Dry Bay.

As for winds, Surface winds will be gusty south of Sumner Strait
overnight. Clarance Strait, Misty Fjords, Ketchikan, and Annette
Island in particular could see SE gusts to 30 kt. Winds aloft in
the vicinity of Ketchikan and Annette Island will not be much
better with SE winds up to 35 to 40 kt at 2000 ft ASL, so expect a
little low level speed shear overnight and possible turbulence.
Wind conditions improve into Monday as the main winds from the
system move into Canada.

MARINE...Outer Waters: Low pressure will move across the eastern
portions of the Gulf through tonight. In advance of it, winds
will become mainly southeasterly and gradually increase. We still
expect a weak barrier jet to form along the northeast Gulf coast
early today and then slowly weaken. By late afternoon and early
evening, winds will generally turn more northeasterly. Around
Dixon Entrance, we also expect a rather significant increase in
wind speeds to around 25-30 kts, with higher gusts. Seas will also
build in that area to around 8 feet before subsiding after 15Z
Monday as winds decrease.

Inner Channels: Although there continue to be a few differences
in the model solutions, especially in regard to the timing of the
incoming system and frontal passage, it still appears that the
most significant increase in winds will affect mainly Sumner
Strait southward. Wind gusts to 35 kt are possible in Clarence
Strait tonight with seas forecast to build to 8 feet. As the low
pressure and front pass later Monday, winds and seas will
gradually diminish. Elsewhere across the inner channels, winds are
expected to remain generally 10 knots or less into Monday, except
for parts of Lynn Canal where winds around 15 knots are possible
at times.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036.

&&

$$

UPDATE...STJ
SHORT TERM...NC
LONG TERM...AGP
AVIATION...EAL
MARINE...Ferrin
HYDROLOGY...Ferrin

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