Juneau, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

568
FXAK67 PAJK 221400
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
500 AM AKST Mon Dec 22 2025

.SYNOPSIS...

Key Messages:

- Widespread cold temperatures and cold wind chills last through
  through early workweek.

- A Taku wind event in Downtown Juneau and Douglas will be
  weakening Monday morning.

- Increasing potential for an overrunning snow event by late in
  the workweek into next weekend.

&&

.SHORT TERM.../Through Monday night/ Well below normal
temperatures and strong northerly outflow continue to be the main
features of the forecast for the panhandle. The coldest
temperatures of this cold air outbreak are currently occurring or
will occur Monday night with some areas of the north seeing temps
dropping below zero while southern panhandle areas will see mostly
teens for lows (especially in wind sheltered areas). These
temperatures are a good 15 to nearly 30 degrees below normal for
this time of year where normal highs range from 34 to 40 degrees
and normals lows range from 26 to 33 degrees. There is no warm up
in sight for the next day to two with cold temperatures
continuing. Only some wind breaking up inversions offers some
chance of warming an area up a little as the wind mixes warmer air
aloft down to the surface. However, winds overall across the
panhandle are showing a diminishing trend over the next 24 hours
so chances of wind sheltered areas seeing any wind to break up the
cold air inversions is diminishing into Monday night.

As for the winds, strong northerly outflow continues with gales
blowing through most of the northern inner channels this morning.
There is a diminishing trend that will be showing up through
Monday night especially in east/west orientated channels. This is
being driven by a reorientation of the pressure gradient across
the panhandle. A low well to the south of the area is moving east
through the period, and that is enough to turn the pressure
gradient to be more parallel to the east/west channels by Monday
night, so expect winds in those channels to diminish. The
north/south channels will largely remain unchanged with respect to
wind speeds though. The Taku winds at Juneau will also be
diminishing with respect to not expecting gusts to 60+ mph after
this morning due to the flow across the ridge line diminishing.

.LONG TERM...This week, we`ll be watching the potential for a
slight shift in the weather pattern that could would the next
round of snow to Southeast Alaska along with some marginally
warmer temps.

The long range computer models, both deterministic and ensembles,
are trying to put a low pressure center in the northern Gulf of
Alaska in the second half of next week. This would allow for the
flow to switch to a more onshore pattern, or at the very least a
weaker outflow. This would weaken the pressure gradient over area,
allowing for wind speeds to weaken a bit beginning around the
Wednesday/Thursday time frame. If/when the low continues its journey
southeastward, the pressure gradient would tighten up again,
allowing for wind speeds to pick back up for the later days of the
week.

As far as snow potential, the EURO and Canadian develop a low in the
northern Gulf as early as Wednesday. Their respective ensembles
mirror this story. The outlier is the GFS. The latest GFS
deterministic run keeps the area dry until late Thursday into
Friday. The GFS ensemble average, however, closer matches the EURO
and Canadian.

For now, moisture amounts are hinting at if the panhandle sees any
snow later this week, it would start out as light snow until Friday
and the weekend.

The 75th percentiles for the EURO and GFS ensembles give the
panhandle less than a tenth of an inch of QPF for Wednesday through
Wednesday night, which would give around 1 inch of snow at most. For
Thursday into Thursday night, the 75th percentiles are giving the
area around a tenth to about a third of an inch of QPF, with the
greater amounts in the EURO, which would give around 1 to 5 inches
of snow over 24 hours. For Friday into Friday night, the 75th
percentiles are giving the area around one to two inches of QPF,
which would give upwards of 12+ inches of snow over 24 hours. The
50th percentiles are giving the area around a half inch to one inch,
which would give around 6 to 12 inches of snow. Saturday`s QPF is
even greater with the 50th percentile around one to two inches,
which would give over 12 inches of snow and the 75th percentile is
over 2 inches, which would be well over 15 inches of snow. The issue
with Saturday`s snowfall forecast is warmer air aloft may slide in,
which would lower total snowfall amounts and some areas in the far
south may even see rain mixed in.

So what are the main takeaways off all this data? For starters, the
75th percentile is an upper bound. So the amounts mentioned above
are on the high-end for current estimates. Secondly, snow is
possible as early as Wednesday but majority of the data is pointing
to it not being much much if it does happen. Thursday could be a
wildcard day that is worth watching closely. Friday and next weekend
could be a very snowy couple of days so that will be worth watching
closely, especially with the jump in 75th percentiles from yesterday
to today.

As far as the slightly warmer temps are concerned, there is a
warming trend but most of Southeast is still likely to be below
freezing. Wednesday`s highs will be generally in the single digits
to teens but by the weekend, highs could be in the teens in the far
north, 20s and 30s elsewhere. For overnight lows, Tuesday night`s
forecasted lows are in the single digits to teens with warmer low
temps in the teens to 30s for the weekend nights. So warmer but
still colder-than-normal.

&&

.AVIATION...

Widespread VFR conditions, with Generally clear skies and outflow
winds continuing through Monday and into Tuesday, albeit with
some weakening of the outflow winds expected. What clouds are
present are largely limited to the southern panhandle, but these
are generally above 5K feet. The bigger story will be winds.
While outflow will remain, some weakening is expected, and low
level turbulence and LLWS will diminish through Monday, though
cannot rule out some sporadic mountain wave activity lingering.
The strongest winds will remain entrenched within the inner
channels and standard outflow areas.

&&

.MARINE...
Inside waters: Outflow conditions and freezing spray remain the
concerns for the inside waters. North/south oriented channels are
expected to remain mostly the same, wind speed wise, through
there will be a slight diminishing trend before outflow starts to
shut off on Wednesday. East/west oriented channels will see a
faster diminishing trend especially along the outer coast as
pressure gradients become more north/south orientated allowing
winds in these areas to diminish by late Monday night or Tuesday.
Overall though freezing spray still remains a problem for a large
part of the inner channels due to the winds, high seas (due to
the high winds blowing down the long linear channels), and cold
air. Heavy freezing spray still plagues Lynn Canal, Taku inlet,
and Glacier Bay through Monday night at least.

Gulf waters: Outflow conditions persist with the highest winds
still coming out of the passes east of Yakutat, Cross Sound, and
to a lesser extents out of Chatham Strait. Higher seas (up to 14
ft) as well as freezing spray are also found in these outflow
areas. This strong outflow is expected to diminish today into
Tuesday as pressure gradients become not as favorable to sustain
them. The higher seas and freezing spray will diminish as the
winds do. Otherwise, winds over the gulf waters are expected to
remain mostly out of the north for the next few days with seas
diminishing down to 6 ft or less as the outflow diminishes by
Tuesday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Extreme Cold Warning until noon AKST today for AKZ317.
     Cold Weather Advisory from noon today to noon AKST Tuesday for
     AKZ317.
     Extreme Cold Warning until noon AKST Tuesday for AKZ318>322-324-
     325-327-329.
     Cold Weather Advisory until noon AKST Tuesday for AKZ323-326-328-
     330>332.
     High Wind Warning until 9 AM AKST this morning for AKZ325.
MARINE...Heavy Freezing Spray Warning for PKZ011>013-021-031-032.
     Heavy Freezing Spray Warning for PKZ022-033.
     Heavy Freezing Spray Warning for PKZ033.
     Heavy Freezing Spray Warning for PKZ034-035-643-671.
     Heavy Freezing Spray Warning for PKZ034.
     Heavy Freezing Spray Warning for PKZ053.
     Heavy Freezing Spray Warning for PKZ644-651.
     Gale Warning for PKZ011>013-022-031-643-644-651-663-664-671.
     Small Craft Advisory for PKZ021-032>035-053-641-642-661-662-672.

&&

$$

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

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