993
FXAK67 PAJK 091846
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
946 AM AKST Tue Dec 9 2025

.UPDATE...Updated Aviation section for 18z TAF issuance

&&

.SHORT TERM...While clearing skies, dry weather, and colder
temperatures continue to spread across the northern half of SE AK,
the southern panhandle remains under the gauntlet as at least two
systems (one for Tuesday and one for Wednesday) are set to bring
rain and accumulating snow. While confidence is high in the
possibility of accumulating snow, confidence in snow totals is
somewhat lower for places like Ketchikan and Metlakatla, as
temperatures look to remain increasingly marginal through much of
Tuesday.

In the north, katabatic cold air outflow will be strengthened on
Tuesday as another low passes to the south, sending temperatures
even lower. Cold weather advisories are in place for parts of the
Icy Strait Corridor and Haines, where wind chills of -15 to -25F
are expected through much of Tuesday; the cold weather will be
particularly noticeable in the far northern panhandle, where wind
chills as low as -50F are expected through Tuesday night.

Further south, the eastern flank of a positively tilted trough
continues to send system after system into the panhandle. However,
confidence in the impacts of the upcoming Tuesday system have
diminished. Although confidence remains high in the development
of a strengthening shortwave trough which will move across the
south, the latest operational runs have indicated the potential
for the system to be somewhat stronger than previously forecast.
This scenario, if it verifies would enable the warm frontal
component of the system to be more successful in (temporarily),
pushing back the arctic boundary, sending snow levels rising back
above 2000 feet across locations like Ketchikan and Metlakatla,
and significantly curtailing potential snow totals. At this time,
given the relative degree of uncertainty of the full strength of
the anticipated WAA push up Clarence Strait, have decided to
retain the Winter Storm Warnings for Annette Island and the
Ketchikan area, but anticipate a greater chance of snow
accumulations being highly variable. As mentioned in previous,
the best chances of significant snow accumulation will remain in
areas more exposed to NE flow (and somewhat shielded from
southerly flow), like South Tongass and North Tongass, alongside
the Ferry Terminal N of Metlakatla. Other locations, like downtown
Ketchikan and Metlakatla themselves however, could potentially see
significantly less snow, with most precip falling as a rain snow
mix. Confidence is higher in the eastern side of PoW remaining
more snow than rain, and thus seeing greater snow totals. More
modest snow accumulations are likely for areas like Petersburg
and Wrangell, depending on how far north the system manages to
advance before being eroded away by cold air outflow. Temperatures
will cool across the southern panhandle through Tuesday night in
the wake of the system, and areas of the southern panhandle that
had been rain to this point may see an inch or two of snow
accumulation as the NW quadrant of the system moves overhead.

.LONG TERM.../Wednesday through Sunday/...Very little changes
made in the long term forecast as the arctic boundary that pushed
down into the panhandle over the weekend continues to march
southward through midweek. Wednesday a quick moving low will
finish dropping snow in the southern panhandle before moving
inland over British Columbia and ushering in a cold dry second
half of the week. Building high pressure in NW Canada and
interior Alaska supported by a deep arctic trough in the upper
levels is creating offshore flow and ushering colder continental
air through the northern panhandle. This air is very cold with 850
mb temps plummeting into the -15 to -25 C range by mid week
across the northern panhandle and near  -10 C over the south. At
sea level this will translate to overnight lows ranging from
single digits above or below zero for the north to teens and 20s
for the south.

Daytime highs will struggle to reach the 20s for the north and into
the 30s for the south as we progress through the week. Coldest
temperatures look to occur Monday night through Wednesday night, but
sub freezing temperatures are likely to stick around into next
weekend. The panhandle from Icy Strait northward will be watched
as many locations will approach their criteria for cold weather
advisories or extreme cold warnings (especially the Haines and
Klondike Highways) through at least mid week. As of this forecast
discussion, an extreme cold warning for Skagway, primarily along
the Klondike Highway, was extended through noon Wednesday for
extremely cold temperatures as low as 45 degrees below.

Strong outflow winds of at least gale force will be blowing along
many northern panhandle channels through most of the week. A
strong 1035 mb high in the Yukon is the main driver of this
outflow and it will persist and strengthen to 1050 mb by late next
week. Expect gusty winds out of many of the outflow areas in the
northern panhandle to start with, but expect outflow out of areas
farther south through the week as the Yukon high spreads into
northern British Columbia by late week. Gaps along the NE gulf
coast will serve as outlets for strong winds as well through the
period. Aside from the above mentioned hazardously cold
temperatures, freezing spray will become a more widespread
problem for many marine areas in the inner channels and along the
NE gulf coast. The freezing spray could become heavy at times in
Lynn Canal, near Taku Inlet, and northern parts of Glacier Bay
throughout the week.

The continuing outflow will also keep most of the panhandle dry
through the mid and long range except for possibly the far south.
There is the possibility of a another snow event for the south
next weekend that is highly dependent upon an upper level ridge
moving over the panhandle at the start of the weekend followed by
another arctic trough replacing the one that dominates the state
for most of the week. One thing is for certain, winter has come to
southeast Alaska.

&&

.AVIATION.../Until 18z Wednesday/...The northern panhandle remains
clear, cold and windy Tuesday morning while the central and
southern panhandle will be seeing snow and lowering CIGs from an
approaching low in the southern gulf. Light snow showers have
already been streaming over Prince of Wales Island and along
Sumner Strait. A more organized band of precipitation is expected
to push into the southern panhandle through late Tuesday morning
bring heavier snow showers to northern Prince of Wales as well as
Wrangell and Petersburg. Southerly winds are expected to bring up
temperatures enough for southern PoW and Clarence Strait up to
Ketchikan to see primarily rain with some snow mixing in with
heavier showers. Low VIS of 1 sm or less due to heavy snow will
be the primary limiting factor bringing conditions down to IFR or
LIFR at times along Sumner Strait and northern Clarence Strait.
By mid Wednesday morning, conditions should improve from west to
east across the southern panhandle as the low moves inland over BC
and precipitation diminishes.

For the period, the northeastern panhandle from around PAJN
northward will receive the bulk of the northerly outflow
conditions and remain windy through the period. Centered aloft
between 1 to 2 kft, llWS values around 25 to 30 kt in magnitude
remain in store around PAJN area out of the NNE.


&&

.MARINE...
Outside: Strong outflow winds continue to dominate the eastern
gulf coastal waters through Tuesday. Gale to storm force winds
with strong storm force gusts are blowing out of interior passes,
as well as any available drainage channel. Only a minor reduction
in strength is expected through Thursday, but winds are overall
expected to stay elevated through the week. Wave heights are
around 7 to 10 ft through the majority of the gulf, with areas
affected by the outflow winds seeing up to 15 ft waves persist
through the week. Freezing spray is possible with strong wind
gusts, mostly along the coastal waters. The central gulf is more
calm, only experiencing disorganized moderate breezes as the low
in the western gulf dissipates.

Inside: Strong gale to storm force outflow winds have persisted
through Monday and are expected to continue through the week. A
very strong pressure gradient in the northern panhandle is forcing
northerly storm force winds with gusts in the 60 kt range down
through Lynn Canal and Stephens Passage, as well as strong gale
force winds with storm force gusts out of Taku Inlet and through
the rest of the inner channels. Wave heights between 8 to 15 ft
are expected in areas of the strongest winds, with the rest of the
channels seeing around 6 ft or less and diminishing overnight.
Channel entrances and areas with greater localized forcing (like
Point Couverden) may see up to 15 ft waves at their peak. The
pressure gradient is expected to only slightly relax overnight,
continuing gale force outflow winds in Lynn Canal and Stephens
passage and strong breezes to near gale force winds for the rest
of the channels through the week.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Extreme Cold Warning until noon AKST Wednesday for AKZ318.
     Cold Weather Advisory until 3 PM AKST Wednesday for AKZ319.
     Cold Weather Advisory until noon AKST today for AKZ320-325.
     Winter Storm Warning until midnight AKST tonight for AKZ328-329.
     Winter Weather Advisory until 3 AM AKST Wednesday for AKZ331.
MARINE...Heavy Freezing Spray Warning for PKZ011>013-031.
     Heavy Freezing Spray Warning for PKZ021.
     Gale Warning for PKZ011>013-022-031-033-642>644-651-662>664-671.
     Small Craft Advisory for PKZ021-032-034>036-053-641-652-661-672.

&&

$$

SHORT TERM...GFS
LONG TERM...STJ
AVIATION...STJ
MARINE...GFS

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