175
FXAK67 PAJK 181728
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
928 AM AKDT Tue Aug 18 2026

.UPDATE...Updated the aviation section for the 18z tafs. Also did
a small update to Lynn Canal and Skagway winds. While the general
message is that winds will be on the diminishing trend today,
keeping them elevated through the morning hours from daytime
heating in Canada, keeping the thermal trough alive and well.

&&

.SYNOPSIS...

Key Messages:

- More seasonable conditions will prevail through the end of the
  week with mostly cloudy skies and periods of rain, especially
  across the north, as multiple systems traverse the region.

- The marine layer and weak onshore flow will keep high temps in
  the upper 50s to lower 60s across the north. Breaks in clouds
  across the south could bring high temps into the mid to upper
  60s and possibly low 70s.

- Marine conditions will improve through the day. The next system
  looks to bring increasing Gulf winds and seas by Wednesday
  night.

&&

.SHORT TERM.../through Wednesday night/...
The front has weakened and cleared the panhandle overnight.
Pockets of low stratus and fog are present across portions of the
central and southern panhandle this morning. A Dense Fog Advisory
is in effect for Kake. High pressure is building back over the
eastern Gulf into the southern panhandle today. Expect lighter
onshore flow bringing marine layer into the panhandle today, with
mostly cloudy skies and periods of light rain across the northern
and central panhandle. Late tonight into Wednesday, a weak
disturbance will ride over the ridge and into the panhandle,
bringing an increased chance of light rain. A frontal boundary
will then straddle the central and northern panhandle Wednesday as
the next low lifts towards the Kenai Peninsula. The low and front
will bring increasing rain potential across the northeast Gulf
coast and into the northern panhandle through Wednesday night,
with moderate to heavy rain at times possible. The cooler, but
seasonable, temperatures will continue across the north, with
highs in the upper 50s to lower 60s. Across the south, some breaks
in cloudiness and slightly warmer temperatures with highs in the
mid to upper 60s, possibly reaching the low 70s.

/Thursday through Sunday/...
Active weather continues into the long term period, especially
over the northern panhandle. To end the work week, an area of low
pressure moves into the northern gulf continuing to bring onshore
flow, rain, and slightly increased winds to the northern and
central panhandle. An area of high pressure southwest of the
panhandle with a positively tilted ridge axis will remain near
Prince of Wales Island. This ridge will likely keep the far south
drier, but a few periods of light showers may occur. That ridge,
southwest of the area, breaks down Friday into Saturday as a
stronger low pushes into the northern gulf. There is still some
uncertainty on how strong this low will be. The strength of the
low will really help to indicate what weather hazards to expect,
like how much rain we may receive and how strong winds may get.
Confidence on the location and timing of this low has slightly
increased, but it is still a ways out.

Temperatures through the long term period remain near average
with high temperatures in the mid to high 60s. There are
indications that areas near Hyder will see temperatures into the
mid to high 70s on Thursday and Friday. The main indicators of
this is continued dry weather along with 850 temperatures between
12 to 15 C. The limiting factor will be the amount of cloud cover
that they receive as the low pressure system moves into the gulf
bringing more moisture into the area.

&&

.AVIATION...

Improving flight conditions through the morning hours today, with
mostly MVFR conditions in the inner waters and IFR to LIFR just
offshore, predominantly in the NE gulf coast. Not expecting these
conditions to last too long in the inside waters, as daytime
heating, ridging and drying aloft looks to raise CIGS to high MVFR
to VFR for most locations. An incoming front tonight is expected
to bring conditions back down to MVFR, with CIGs between 1500 and
2500 ft for the central and northern panhandle. There is the
possibility for IFR conditions, even if they do not strictly
happen at TAF sites, for the outer coast. Additionally, weak
forcing will at least bring a few light showers to drizzle for the
aforementioned areas. The southern panhandle does look to get
these lower conditions, specifically Ketchikan and Wrangell, but
this looks to occur just outside of the TAF issuance.

As for winds, relatively light winds overall, with no LLWS
concerns. Skagway continues to be a sore spot for winds, however,
winds do look to lax tonight as upper level support shifts out of
the area.

&&

.MARINE...
Outer waters: Building high pressure in the gulf contributed to
decreasing winds overnight, and this trend will continue through
Tuesday. Waters near Cross Sound are the exception here, with
isallobaric winds (rising pressures) increasing near this area,
channeling into Cross Sound up to 15 knots. Similar story for
wave heights, but with a predominantly southwest swell up to 6 ft,
wave are expected to be slow to diminish. Buoy 083 off Cape
Edgecumbe is reporting 8 ft seas dominated by a westerly swell
with a wave period around 10 seconds. Waveheights up to 10 feet
were observed up to 3am. Looking ahead in the week, a system
moving up along the western gulf late Wednesday into Thursday
morning will develop a barrier jet bringing increased seas and
winds to the coast near Cape St Elias.

Inside waters: While some increased southwesterlies near the
mouth of Glacier Bay and Cross Sound from the aforementioned
isallobaric winds are present, they are expected to gradually
weaken through the day today. With the gradually increasing high
pressure over the panhandle and lower pressure over the interior,
Lynn Canal is expected to hover between 15 and 20 kt through the
day with gusts up to 30 kt, particularly near Taiya Inlet. Other
than the winds up north, the primary hazard for marine travel will
be persistent low clouds, mist, and fog potential, primarily for
the central and southern panhandle through the morning hours.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ642>644-652-662>664-671-672.

&&

$$

SHORT TERM...DS
LONG TERM...EAB
AVIATION...NC
MARINE...STJ

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