454
FXAK67 PAJK 120634
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1034 PM AKDT Sun Oct 11 2026

.UPDATE...


&&

.LONG TERM...

Thursday morning sees the beginning of a stronger atmospheric
river move into the area. Some rather impressive dynamics look to
be associated with this storm, with strong initial warm air
advection, and relatively cold air advecting eastward. These
ingredients coupled with sea surface temperatures still around
the mid 50s means that the environment leans more towards the
convective. Furthermore, a strong jet aloft with plenty of
divergence behind the warm front sets the stage for meso vertices
forming along the front. These cause a number of issues: timing,
location, and intensity of rainfall and highest winds can shift
drastically. Individual model runs tend to struggle with these
environments, with run to run consistency of both the GFS and EC
inconclusive on individual features. Ensemble guidance provides a
clue on the location of highest wind speeds and rainfall however.
At this point, the southern half of the panhandle has the highest
likelihood of longer duration, heavier rainfall. The specifics
regarding the hydrology portion of this storm are noted in the
hydrology section.

Looking towards the weekend, there is roughly a 60-40 split of
active weather continuing and a stronger low passing south
respectively. If active weather continues, then generally
southerly winds will accompany mostly rain for the panhandle. For
the low passing south, this would invite stronger, downsloping
northerlies, which would dry out the panhandle and bring cooler
temperatures overnight.

&&

.HYDROLOGY...

Impressive plume of moisture looks to be associated with the
incoming atmospheric river Thursday morning. Strong WWA ahead of
the moisture looks to raise freezing levels to above 5000 ft, with
an atmosphere relatively saturated. Associated PWAT via ensemble
mean looks to exceed the 95th percentile for this time of year for
the southern panhandle. This coupled with the strong flow aloft
means that IVT will likely exceed 500 kg/ms at around 80%. The big
question here is timing of this moisture, and if any mesoscale
features will keep this flow of moisture directed at the southern
panhandle for longer. Dynamics continue to favor higher rain
rates, with divergence aloft and stronger 850-700 mb southerly
flow. Rain rates could exceed 0.3 in/hr for longer periods of
time, and exceed 0.5 in/hr at elevation. Flooding is certainly
possible with this rainfall intensity, but uncertainty in
duration (see long term) has cast some doubt on overall impact
level. Stay tuned for updates as the event approaches.

&&

.AVIATION...

MVFR/VFR conditions are and will likely remain the predominant
situation over the next 24 hours. When the front makes its final
exit out of the panhandle, winds will be rather calm for most of SE
AK. In addition, rain will become less consistent in its coverage
with some weak ridging toward the southern panhandle. Throughout the
day on Monday, clouds will generally lift above 3kft, hopefully
providing for improved flight conditions to start the week.

The northern panhandle may remain rainier for longer, as well as
retain lower cigs as there will be some continued onshore flow. By
Monday afternoon/evening rain chances are low enough for central and
southern panhandle sites that rain has  largely been removed as the
prevailing weather condition.

&&

.PREV DISCUSSION......ISSUED AT ... 305 PM AKDT OCT 11

SYNOPSIS...

Key Messages:

- A front swinging through the region will bring gusty winds and
  moderate rain to the panhandle through tonight, especially
  across the northern half of the panhandle.

- Quieter weather for the first part of the work week with
  lighter rain showers possible.

- A larger, impactful system to move into the Gulf midweek and
  impact SEAK by late week.

SHORT TERM...
Sunday into mid-week will feature some rounds of rain and some
wind but nothing we cant handle. Touching on rain, 850mb temps
remain too warm to see snow at sea level. Folks heading up the
passes into Canada will likely see a mix of rain and snow falling
at times but no impacts expected. Widespread rain of 1 to 2
inches tonight becomes showery Monday afternoon. While the central
and north see drier conditions Tuesday morning, another slug of
rain moves into the south.

For winds, a gale force front moving into the coast of the
Alexander Archipelago Sunday will increase the north-south
pressure gradient through Sunday night, freshening up southerly
winds to 20 to 30 knots, more in the marine discussion below. For
folks nestled safely on terra firma, gusty winds of 20 to 35 mph
likely in the north tonight, highest in Skagway. Winds begin to
come down Monday. These smaller systems will warm us up for a
much bigger system Thursday into Friday, more info in the long
term.

LONG TERM.../Tuesday through Friday/...A weaker wave will move
north from Haida Gwaii Tuesday and Wednesday, providing enough
disturbance to generate scattered showers, mostly in the southern
panhandle. The larger impacts may come as early as Thursday from a
much deeper low. The latter low will intensify in the western
Gulf, and will have ample to mature as it looks to be held out
over the open waters of the Gulf by some Fujiwara Effect related
to a smaller orbiting low which most guidance has combining
together.

By Friday the extent of its influence will likely reach us here
in SEAK. Exact timing still differs between deterministic guidance
runs. One of the larger variables being how long the two lows
orbit one another before joining and allowing the resultant low to
track east. A later arrival will most likely result in a stronger
system, but there is good confidence in strong gusty winds,
especially over coastal waters, and widespread rainfall Friday
heading into the weekend.&&

AVIATION...VFR to MVFR conditions continue for most of the
panhandle this afternoon with the exception of the Yakutat area
which has seen conditions down to IFR. With the front pushing
through, there should still be some decreasing conditions across the
panhandle. The main concern will be ceilings decreasing with the
rain but some visibility reductions are also possible, especially
during the heavier periods of rain. Another concern will be after
the front passes. Current satellite imagery shows clearing behind
the front which could allow for some fog development this evening
and overnight. Confidence for the TAFs for this evening is moderate
with some reduced conditions being noted but not as significant as
what some forecast guidance is hinting at.

MARINE...
Outer Waters: A front in the Gulf of Alaska has brought gale force
winds from Cape Suckling to Cape Fairweather, and elevated seas
across the Gulf. As the low pressure system pushes into the
Panhandle, expect the front to dissipate and marine conditions to
improve through Monday morning. Behind the front, a low in the
Bering Sea will continue onshore flow for Southeast Alaska.
Tuesday, a low pressure system is expected to form near Kodiak
Island and another low will form in the North Pacific. As the
northerly low moves toward Prince William Sound Tuesday morning,
expect a easterly barrier jet with winds up to 20 kts near Cape
Suckling. The next more organized system arrives Wednesday night
into Thursday.

Inside Waters: A front is pushing into the Alaska Panhandle and
leading to winds up to 25 kts and seas up to 5 feet. As the front
dissipates, expect the marine conditions to generally improve for
the inner channels. With the low in the Bering Sea, expect generally
onshore flow to continue for Southeast Alaska. Monitoring the
potential for two lows to develop Tuesday: one near Kodiak Island
and in the North Pacific. Guidance still disagrees on the exact
track, but generally bring it toward Haida Gwaii. If the low
tracks further north, this may increase winds in the southern
inner channels. However, the main impactful system for Southeast
Alaska looks to arrive Wednesday night into Thursday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-013-031-034-641>643-661-662-672.

&&

$$

SHORT TERM...AP
LONG TERM...NC
AVIATION...VFJ
MARINE...Musall

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