Juneau, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXAK67 PAJK 230619
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
919 PM AKST Mon Dec 22 2025

.UPDATE...after the 06z TAF issuance. Minimal changes to the
previous forecast. Clear skies persisting, with the outflow
pattern for the northern half the panhandle so only hazard will be
turbulence or LLWS. The southern third though has a few more
clouds from a system cutting just south of the panhandle has
spread some clouds over the SE panhandle area. A few flurries may
occur as mentioned.

&&

.PREV DISCUSSION...ISSUED AT 329 PM Dec 22...

SYNOPSIS...

Key Messages:

- Widespread cold temperatures and cold wind chills last through
  the middle of the week.

- Increasing potential for a pattern change for the end of the
  week into the weekend.

- Potential for snow event for the central and northern panhandle;
  southern panhandle could see snow turning to rain.

SHORT TERM...Cold weather for the area continues as outflow continues
to be the main focus for the short term forecast. Temperatures
are expected to be similar to today with places not seeing the
wind staying cold throughout the day tomorrow. Areas favored by
windy outflow conditions are expected to continue to see strong
winds through the storm term period. The main concerns being for
Skagway as well as some stronger winds for the Downtown Juneau
area. As the pressure gradient shifts more to the east, winds are
expected to increase out of the east/west oriented channels more
which will see some increasing winds out of the Stikine river
delta as well as Taku Inlet. No major changes are expected for the
short term forecast with changes coming to the area expected for
the long term period.

LONG TERM...We continue to watch the potential for a
slight shift in the weather pattern that would give the next round
of significant snow to Southeast Alaska along.

The long range computer models, both deterministic and ensembles,
are trying to put a a couple low pressure centers in the northern
and eastern Gulf of Alaska later this week. The first low 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 decrease a bit beginning
around the Wednesday/Thursday time frame. When the low continues its
journey southeastward Thursday into Friday morning, the pressure
gradient would tighten up again, allowing for wind speeds to pick
back up ahead of the next low that is forecasted to move northeast
into the Gulf. In particular, the N-S gradient will increase across
the northern half of the panhandle as the low slides to the south of
the panhandle, bringing near gales down Lynn Canal Thursday. As the
low moves southeast, before the larger low approaches from the west
Friday night, there will be another brief lull in the winds into
Friday particularly along the southern panhandle. Winds begin to
pick up across the entire panhandle Friday night into the weekend as
the stronger low approaches, and a gale force front begins to move
in from the southwest. These southerly winds moving into the
panhandle will allow for some warming across the panhandle alongside
bringing precipitation through from W to E into the start of the
weekend.

As far as snow potential, the EURO and GFS have come into greater
agreement over low tracks and 500mb flow. The Canadian has become
the outlier. The current forecast leans towards the story that the
EURO and GFS tell. The biggest difference in the Canadian is the
overall positions of the upper level flow and surface level
pressures would keep the cold air in place longer, giving southeast
Alaska much greater amounts of snow. But there is more confidence on
the story in the EURO and GFS, so for now, the forecast thinking
leans heavily on the EURO and GFS.

Moisture amounts are hinting at light snow on Thursday, with a break
on Friday. Friday night into the weekend is looking like another
significant weather event that could produce significant amounts of
snow for parts of Southeast Alaska.

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 4 inches
of snow over 24 hours. Greatest amounts along the coast.

For Friday into Friday night, the 75th percentiles are less than
previous runs, giving the area around half inch to 1 inch of QPF,
with the greatest amount along the coast, which would give upwards
of 10 inches of snow over 24 hours if it all falls as snow. The 50th
percentiles are giving the area around a quarter inch to half inch,
which would give around 4 to 7 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 well over 2 inches, which would be well over 15 inches
of snow if it all falls as 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 a
total switch to rain.

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. The 50th percentile is a
middle-ground estimate. Thursday`s snow is looking like a quick-hit
of light snow with a break in the snow for Friday. Friday night into
the weekend will be a challenging forecast with the surge of
moisture and warmer air coming up from the south. The farther south
you are, the greater chance of seeing a full transition to rain. The
Farther north you are, the greater chance of seeing another long
duration snow event.

Either way, stay tuned into the forecast but be prepared for a snowy
weekend.

AVIATION.../through Tuesday afternoon/...
Generally VFR flight conditions expected with mostly clear skies
and outflow winds continuing. Some mid to high level clouds AOA
6kft, mainly across the southern panhandle. A few light snow
showers are possible across the far southern panhandle, including
PAKT and PAPG, which could briefly bring MVFR CIGs. While outflow
will remain, low level turbulence and LLWS will also persist with
winds 1-2kft aloft 20-30kts.

MARINE...
Outside (Gulf and Coastal Waters): Outflow winds continue across the
Gulf. The strongest winds will continue to be out of gaps in terrain
such as Cape Spencer and near Dangerous River. These winds continue
to weaken somewhat but some locally stronger winds remain possible
as we head into the middle of the week before starting to weaken.
Wave heights are expected to diminish for most of the Gulf but the
largest waves will persist in the areas where the outflow winds
continue to remain high. The N-NE swell is expected to weaken going
into Tuesday before shifting to a S-W swell component by the time we
get to Wednesday.

Inside (Inner Channels): Outflow winds continue this afternoon as
the wind speeds continue to remain elevated with gales to strong
gales continuing for Lynn Canal and Stephens Passage. Outflow winds
are expected to persist through the start of the week before
starting to diminish as we get into the middle part of the week.
With the diminishing wind speeds, wave heights and freezing spray
concern will start to trend down as well. Until then, the strongest
winds are expected to continue down Lynn Canal as well as Stephens
Passage and down towards Five Finger lighthouse. With a system
moving in for the end of the week, the winds will come down before
increasing again.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Extreme Cold Warning until 6 AM AKST Wednesday for AKZ318.
     Extreme Cold Warning until 6 PM AKST Tuesday for AKZ319-323.
     Cold Weather Advisory until 6 PM AKST Tuesday for AKZ320-326>331.
     Cold Weather Advisory until noon AKST Tuesday for AKZ321-332.
     Cold Weather Advisory until 3 PM AKST Tuesday for AKZ322.
     Cold Weather Advisory until 9 AM AKST Tuesday for AKZ324.
     Extreme Cold Warning until 6 AM AKST Tuesday for AKZ325.
     Strong Wind through Tuesday afternoon for AKZ325.
     Cold Weather Advisory from 6 AM to 6 PM AKST Tuesday for AKZ325.
MARINE...Heavy Freezing Spray Warning for PKZ011-012-031.
     Heavy Freezing Spray Warning for PKZ013.
     Heavy Freezing Spray Warning for PKZ013.
     Heavy Freezing Spray Warning for PKZ021-034.
     Heavy Freezing Spray Warning for PKZ021.
     Heavy Freezing Spray Warning for PKZ032.
     Heavy Freezing Spray Warning for PKZ032.
     Heavy Freezing Spray Warning for PKZ053.
     Heavy Freezing Spray Warning for PKZ053.
     Gale Warning for PKZ011>013-022-031-643-644-651.
     Small Craft Advisory for PKZ021-032>036-053-641-642-661>664-671.

&&

$$

SHORT TERM...SF
LONG TERM...GJS/Contino
AVIATION...DS
MARINE...SF

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