Winter Storm and High Wind in Alaska, December 11 to 12, 2023

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
549 AM AKST Mon Dec 11 2023

.SHORT TERM...A series of systems, some of them storm force, will
move into the panhandle through the week, bringing high wind,
rain, and snow to SE AK. The forecast remains largely on track,
with the biggest change being delaying the onset of significant
precipitation for the southern half of the panhandle until Monday
night. Otherwise, The first front will impact the panhandle through
the day on Monday. The second system will arrive Monday night,
moving into the panhandle through Tuesday, with still another system
arriving during the day on Tuesday. Winter storm warnings have been
posted for the Haines and Klondike Highways, a flood watch has been
issued for much of the remainder of the panhandle, and High Wind
watches have been issued for the southern panhandle, Juneau, and
Skagway. Strong wind headlines have been issued for many locations.
Rain may be heavy at times for much of the area, and river rises are
anticipated. Forecast confidence is above average. For additional
details, see the long term discussion.

.LONG TERM...Complicated system to impact the panhandle beginning
this Monday and continuing through Wednesday. A storm force low
will move into the north central gulf this Monday with a wave
maximizing along the panhandle gulf coast Tuesday morning. An
embedded wave will move up from the south in the triple point of
the low to generate additional storm force winds and potential
high winds over land areas for the southern panhandle. This wave
will continue to work its way northward through the panhandle and
pass into the Yukon. As such, high wind watches were issued for
the southern panhandle communities excluding Wrangell, Juneau, and
Skagway, as the embedded wave moves northward.

For rain, kept the forecast mostly on track. 12 and 24 hour rainfall
totals for the secondary, embedded wave moving northward continue to
be approaching 10 year and, in a few cases, 25 year return
intervals. With rising snow levels and high rain rates, a flood
watch was issued regarding the potential for increased flooding
potential in the central panhandle. For the southern panhandle,
heavier rain rates combined with wind gusts approaching 60 mph has
historically lead to an increased risk of landslides.

Finally, for the highways: A winter storm warning has been issued
mainly for higher elevations on the Haines and Klondike Highway.
Less confidence exists for the Klondike Highway than the Haines
highway. For the Haines highway, 80% of models have the USA side of
the Haines Highway transitioning to rain Tuesday morning. However,
for the Klondike highway, because of the higher elevation, snow
could stay in place for longer than expected. Furthermore, it will
depend on when and if the higher southerly wind speeds push near
Skagway.

&&

.AVIATION...Aviation weather is looking to get worse and worse as
the day goes on. Precipitation (mostly rain) has already started
for the northern half of the panhandle with mostly MVFR conditions
and gusty winds in various areas. Southern panhandle is mostly VFR
this morning with lighter winds. The precip and wind in the north
will gradually spread over the rest of the panhandle through the
next 24 hours. Expect deteriorating conditions late tonight into
Tuesday especially as a stronger wave on the front comes inland
spreading higher winds, and heavier rain. Wind shear and
turbulence are strong possibilities as well, especially tonight
into Tuesday.

&&

.MARINE...A series of fronts moving into the panhandle will bring
storm force and gale force winds to the outer coastal waters, and
gale force and small craft winds to the inner channels through
much of the week. Storm force winds may also be possible for
Clarence Strait at times. Winds will increase through Monday,
before reaching their maximum strength Monday night through
Tuesday night.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until noon AKST today for AKZ317.
     Strong Wind from this evening through late tonight for AKZ317-
     321.
     Strong Wind until 6 AM AKST early this morning for AKZ318.
     Winter Storm Warning until 6 AM AKST Tuesday for AKZ318-319.
     High Wind Watch from Tuesday evening through Wednesday morning
     for AKZ318-325.
     Flood Watch from late tonight through Wednesday morning for
     AKZ320>330-332.
     Strong Wind from this evening through late tonight for AKZ323-
     325.
     Strong Wind late tonight for AKZ327-329-330-332.
     Strong Wind late tonight for AKZ328.
     High Wind Watch from Tuesday morning through Tuesday evening for
     AKZ328-330-332.
MARINE...Storm Warning for PKZ642-643-652-662>664-671.
     Gale Warning for PKZ013-031>036-053-641-644-651-661-672.
     Small Craft Advisory for PKZ011-012-021-022.

&&

SHORT TERM...GFS
LONG TERM....NC
AVIATION...EAL

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