327
FXAK67 PAJK 171446
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
646 AM AKDT Thu Sep 17 2026

.UPDATE...Update for the Gale Warnings issued for Friday for
northern Gulf coastal marine zones.

&&

.SYNOPSIS...

Key Messages:

- Quieter weather for Thursday with lighter winds and mainly dry
  conditions and partial clearing.

- Multiple systems to impact the region late Thursday night into
  the weekend, with the potential for heavy rain, gusty winds and
  increasing seas.

- Cooler but seasonable temperatures for the period, with daytime
  highs generally in the 50s.

.SHORT TERM.../through Friday night/...A bit of a break from the
active today with light winds and partial clearing as the front
the brought the rain and gusty winds Wednesday has shifted south
and weakened over Dixon Entrance early this morning. Weak onshore
flow could bring spotty light showers or drizzle across northern
panhandle and northeast Gulf coast today. The front will begin to
retreat back north across Thursday night into Friday as
strengthening low pressure lifts northeast into the Gulf. and
approaches the north Gulf coast by late Thursday night, with rain
chances rapidly increasing across the panhandle.

As we head into Friday, a low pressure system moves northward into
the NE gulf coast with front lifting into northern panhandle.
Friday night, the low looks to jump ashore near to west of
Yakutat, with a trailing cold front and a deeper moisture plume
ahead of it dragging east across the panhandle. Stronger winds
with moderate to heavy rain are expected with this system.
Through Friday night, rain totals look to be around 2 inches for
the north/central panhandle and northeast Gulf coast, with around
1 inch for southern areas. Although periods of moderate to heavy
rain are likely, no flooding is anticipated at this time for the
Friday system.

Active weather will then continue as a stronger low pressure
system brings more strong wind and heavy rain for the weekend. See
the long term forecast discussion for more information.

.LONG TERM.../Saturday through Thursday/...Upper level features
continue to show a rather active pattern through the long range
period. A broad upper trough stretching from the Russian Far East
to NW Canada will be the main weather maker for the weekend into
early next week. The trough is anchored by an upper low that
eventually positions itself over SW mainland Alaska. The broad
trough stays in place into early next week, but several short
waves are evident rotating around the southern edge of it. There
are indications now that the trough will then sharpen and narrow
over the Gulf of Alaska by mid next week as ridging begins to
build over the aleutians and Bering Sea.

At the surface, the weekend into early next week is looking
interesting with a strong broad area of low pressure moving into
the gulf from the SW and heading toward the northern gulf coast.
The track this low is taking is shaping up for at least a day and
a half of strong and moist onshore flow from the SW for the entire
panhandle and gulf. Winds in the gulf will show widespread 25 to
35 kt winds Sat into Sunday, and the northern inner channels could
see several areas of 20 to 30 kt during the same time period. As
for rainfall, expected 24 hour rainfall amounts are getting into
the 1.5 to 3 inch range for many areas for around 2 to 3 days in a
row starting Friday. Heaviest rain rates still appear to be from
Saturday evening into Sunday. Forecast 24 hour annual return
intervals from the NBM are showing greater then 50 percent
probability of exceeding 2 yr return intervals in many parts of
the northern inner channels by Sunday afternoon and greater then
15 percent for exceeding 5 year return intervals in some
locations.

In addition to the stronger onshore SW flow the system will
bring, it its wake is a shot of cooler air that will be coming in
from the west. Forecast convective indices are already indicating
that Sunday into Monday may be rather convective/showery in nature
as the cooler air moves in and the potential is there for some
thunderstorms across a large area of the gulf and outer coast at
that time. Retained the area of slight chance and chance thunder
that has been in the forecast, though it now looks like that
potential for thunderstorms could linger into Monday night now.

Damp weather continues into the first half of next week with
onshore flow continuing, but showers and W to SW winds will not be
as strong. There are indications of more systems moving into the
gulf next week, with agreement growing on a low coming up from the
S Tuesday night into Wednesday. However timing of that system and
where it goes once it gets into the gulf is still an open ended
question at the moment.

.AVIATION.../through 12z Friday/...An improving trend is expected
through the day Thursday, before another system moves into the
southeastern gulf by the end of the period. Lowered conditions
continue for most TAF sites south of the Icy Strait Corridor as
the remnants of a front moves out of the southern panhandle. The
northern panhandle is already seeing VFR conditions, with CIGs of
3000 to 5000 ft. Gusty onshore winds in Skagway and Haines are
beginning to steadily decrease, but will remain around 15 to 20
kts for the next few hours. Parts of the central and southern
panhandle will continue to see MVFR to IFR CIGs through mid
morning, with the possibility of fog for any communities that see
periods of clearing. With onshore flow behind the front, a chance
of showers remains for the southern panhandle, though broken CIGs
may be possible in between. Towards the end of the period, another
front will be moving northeastward towards the southern outer
coast of the panhandle. Overcast CIGs AoB 5000 ft will begin to
move in for some southern sites preceding the front early Friday
morning, with the chance of rain increasing by 12z Friday.

.MARINE...
Outside Waters:
Fairly benign marine conditions today with light to gentle winds
and seas 4 to 6 ft. A strengthening low lifting into the Gulf will
bring increasing southerly to easterly winds winds and seas
beginning Thursday night. Strong breezes to gales and 8 to 12 ft
seas for the Gulf and outer coastal waters on Friday as the low
lifts north through the Gulf. A brief lull in winds and seas is
expected late Friday night into early Saturday morning. Another
large low lifting into the Gulf will bring rapidly deteriorating
marine conditions on Saturday that will continue through the
weekend, with strong breezes to gales and large seas 12 to 18 ft
are likely.

Inside Channels:
Fairly benign marine conditions with winds light to gentle across
the panhandle, but remain moderate to fresh over Lynn Canal this
morning, then lowering this afternoon as the gradient weakens.
Predominately S to SE-ly winds will begin to increase late
Thursday night as the low pushes into the Gulf and front begins to
lift back north. Winds increasing to fresh to strong by Friday
afternoon and continue through Friday night, with wave heights
building to 3 to 5 feet. The elevated winds and seas will
continue into the weekend as another larger low moves into the
Gulf. Gales are possible for the inner channels, especially
Clarence Strait and northern Lynn Canal.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Dense Fog Advisory until 9 AM AKDT this morning for AKZ327.
MARINE...Gale Warning for PKZ644-651-652-664-671-672.
     Small Craft Advisory for PKZ011>013-021-031>034-036-053-641>643-
     661>663.

&&

$$

SHORT TERM...DS
LONG TERM...EAL
AVIATION...ZTK
MARINE...DS

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