Graphical Hydro Meteorological Discussion

580
FXAK68 PAFC 110130
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
430 PM AKST Wed Dec 10 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Key Messages:

- Gusty winds will continue through the extended forecast. The
current round of winds will continue through Thu morning. Winds
diminish for a brief period between Thu night through Fri
morning. Winds increase again Fri night in Valdez, the Matanuska
Valley, and the waters around Kodiak Island with lower
confidence with how long those winds will remain elevated.

- Cold temperatures and wind chills are expected to persist until
at least the end of this week. A Cold Weather Advisory is
currently in effect through Fri afternoon for the Copper River
Basin and through the Thompson Pass area.

- You can reduce your risk of hypothermia or frost bite by
protecting your skin from exposure and wearing appropriate
clothing while outdoors. Keep emergency supplies with you in
your home and while traveling whenever possible. Consider
wearing your cold weather gear while you are driving longer
distances through frigid temperatures. Know the signs of
hypothermia and check on others.

Discussion:

The forecast is characterized by a couple of key words: cold and
windy. An upper trough is currently passing through Southcentral
Alaska. This is allowing for gusty winds in gap areas including
Valdez, the waters around Kodiak Island, and the Matanuska Valley
near Palmer. However, due to the weaker nature of the trough,
these winds are not nearly as strong nor will they be as lengthy
as the prior event. Due to lighter winds and the presence of an
Arctic air mass, temperatures are dropping to the single digits
and negatives for inland areas. The Copper River Basin in
particular, is very cold with temperatures dropping to 40 to 50
below zero in some areas. As the trough moves out of the area to
the south, winds will gradually decrease by Thursday, becoming
mostly calm in the afternoon.

Friday morning continues the relatively calm, but very cold
conditions. However, by Friday afternoon, a strong upper trough
drops into Southcentral. The first effect of this trough is gusty
winds in Whittier and Seward, reaching over 40 mph through
Saturday. Then, gusty winds will return to the Matanuska Valley
and Valdez. The current thinking is that Valdez will have the
worst of the winds with gusts up to 50 to 60 mph by Saturday. The
Matanuska Valley will also see gusty winds, but these will likely
not be as severe nor as long lasting as the winds from last
weekend with gusts from 50 to 60 mph are expected. However, the
situation is still developing and could change on a dime. Another
round of cold air also arrives on Saturday. This air mass seems to
be colder than the previous one, so temperatures for next week
could be very cold. Another impact of this second round of Arctic
air is a larger temperature gradient between the ocean and land.
This means that gap winds especially in Valdez could linger on for
a longer period. The forecast could still change and conditions
could either look better or worse depending on the track of the
upper trough, so continue to monitor the forecast for updates.

JAR/Rux

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3)...

Conditions across Southwest Alaska and much of the Bering
Sea/Aleutians remains unchanged over the next few days. There
will be some warmer air moving over the Mainland Thursday
night/Friday, raising temperatures to mid 20`s along the Kuskokwim
Delta and western Bristol Bay on Friday. The warming will be very
brief as the air mass passes through quickly and cold air filters
back in from the northeast to drop temperatures again over the
weekend. Mostly dry conditions will continue, the exception will
be inland Kuskokwim Delta and lower Kuskokwim Valley, as well as
along the Kilbuck/Kuskokwim Mountain ranges. Snow is expected
along the aforementioned areas Thursday night/Friday morning as a
shortwave skirts through. No significant snow accumulations are
expected. Gusty gap winds will continue south of the Alaska
Peninsula through tonight as cold air and a tighter pressure
gradient stays in place. Winds are expected to start letting up
Thursday afternoon with some warmer air moving in. Winds may pick
up again Friday night/Saturday once cold air returns. Further
west, a front moves over the Western Aleutians, bringing rounds of
gale force winds and rain Thursday night and Friday. The front
will not progress further eastwards due to high pressure holding
steady over the Bering Sea.

&&


.LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)...

This weekend, an expansive area of high pressure will be centered
over the northern Bering Sea and extend across the rest of the
Bering Sea. This high pressure will aid in pulling Arctic Air
south across the state, causing a trough to dig across the
southern mainland and around a low in the Gulf of Alaska. This
will create the potential for another round of prolonged high
winds through gaps and passes, cold temperatures, and wind
chills. A shortwave low will descend from eastern Russia Monday
afternoon, but remain offshore until it crosses the Alaska
Peninsula by Tuesday morning. A complex surface low in the Gulf of
Alaska could retrograde just enough early next week to bring some
light snow to the north Gulf coast and parts of the Copper River
Basin, but forecast confidence is still low. Otherwise, dry
conditions continue region-wide, which could persist for the next
several weeks as this general pattern of cold, dry weather looks
to stick around.

&&

.AVIATION...

PANC...VFR conditions will persist. Northerly winds are expected
to increase to 10 to 15 kt this evening through mid-day tomorrow
before decreasing tomorrow night.

&&


$$

935
FXAK69 PAFG 110037
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
337 PM AKST Wed Dec 10 2025

.SYNOPSIS... Cold weather continues across Interior Alaska, with
many areas seeing temperatures deeply in the negatives. The North
Slope, which is in the single digits above or below, will itself
drop into the negative teens by late this evening as colder air
moves in behind a cold front and snowfall ends. From Thursday
through the weekend as a low from Siberia moves along the Arctic
coast from west to east, it will bring widespread snowfall of at
least an inch with much warmer temperatures to most of Alaska north
of the AK Range. On the North Slope, winds will increase today and
especially tonight into tomorrow as the low approaches, which could
result in blowing snow and reduced visibilities at times, especially
where they combine with falling snow. Early next week, very cold
conditions settling in over the region could drop temperatures into
the -40s or -50s in much of Eastern Alaska, even outside typical
cold spots.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Cold weather will continue across the Interior today before
warming Thursday and Friday. Cold valley locations will see lows
in the -30s and -40s, with the Upper Tanana Valley falling to
around -50F, or locally even down to -55F for a few locations,
such as Chicken.

- Beginning tomorrow, another system will move into the area and
yield snow totals widely of around 1 to 3 inches through the
weekend, with higher totals of over 4 inches possible from the
north slopes of the Western AK Range to the White Mountains.

- Considerably warmer temperatures are likely on Friday with this
system, with highs widely rising into the positive single or
double digits.

- Early next week, much colder air is going to settle back into
the area, especially over the eastern half of the Interior,
which may allow for even colder temperatures to be possible.
Some areas, such as the Yukon Flats and Upper Tanana Valley,
could see temperatures drop enough for there to need to be Cold
Weather products issued.

West Coast and Western Interior...
- Cold weather with lows in the negative teens and 20s will
continue through tonight ahead of the next system.

- Winds will begin to increase out of the north through Windy and
Isabel Passes beginning early Friday morning and lasting
through Saturday morning, with blowing snow and reduced
visibilities down to 1/2 mile or less as a result at times.

- From tomorrow and through the weekend, much warmer temperatures
are expected, with increasing clouds and generally around 1-4 inches
of light snow. Highest totals are likely on the Chukchi Sea coast
and elevated parts of the southern Seward Peninsula.

- Temperatures will return to more seasonal values with drier
conditions going into the early part of next week.

North Slope and Brooks Range...
- Southerly winds will begin to increase through Anaktuvak Pass
ahead of the approaching low pressure system by later in the
evening tomorrow. These may reach criteria, with ground
blizzards and likely whiteout conditions begin possible through
Friday. These winds will shift westerly after passage of the
front, which will allow for winds to weaken, but snowfall will
likely continue through the weekend.

- A more robust wave of snow is expected to move in across the
region going into the weekend as a low moves along the Arctic
coast from west to east. 2 to 4 inches of snow are widely
possible across the area. Higher totals are possible in the
Brooks Range and Arctic plains, mostly east of the Dalton
Highway. Portions of the eastern Brooks Range southeast of
Sagwon may receive between 6-8 inches of snow.

- As the low moves along the coast, widespread winds of 25 to 35
mph, with higher gusts, will shift from SW to W and could
combine with falling/fresh snow to allow for blowing snow, which
may temporarily reduce visibilities.

&&

.FORECAST ANALYSIS AND DISCUSSION...
A weak upper level trough is continuing to skirt across the
southeastern portion of the state, with generally high pressure
conditions persisting elsewhere for the moment. This has allowed
for temperatures to be somewhat slightly modified and warmer with
the mid-level clouds passing overhead. There will begin a change
in the overall pattern with an area of low pressure moving in from
west to east across the entire state. The Arctic frontal boundary
associated with this will be advancing in across the North Slope.
The tightening of the surface pressure gradient with this low
transitioning from the Chukchi Sea and over into the Beaufort Sea
will allow for there to be very strong winds to develop across the
Arctic Coast and Plains. Because of this, there could be blowing
snow at times (either from precipitation falling or from snowfall
already on the ground) and this may occasionally reduce
visibilities at times until the winds switch around to a more
westerly direction and weaken in the pass. Due to upsloping,
higher snowfall amounts are anticipated within the eastern Brooks
Range, east of Dalton Hwy. For some of the west facing slopes,
there could be some locations receiving anywhere from 6 to 8
inches through the weekend. As this system continues to move off
into northwestern Canada, it is going to draw in colder air on the
backside of the low, which will filter in across the Arctic
Plains. It will also create a strong pressure gradient just off
the northeast Arctic Coast. Winds will become very strong just off
the coast, and gusts may approach 60 mph at times. This will
result in blizzard-like conditions from Prudhoe Bay to Kaktovik,
with significantly reduced visibilities at times.


Further south into the Interior, the warmer air advection will
infiltrate along with increasing clouds and the chance for snow.
Generally, total snowfall amounts expected through the weekend will
be on the order of 1 to 3 inches for most locations, although there
will likely be some higher amounts for locations within the White
Mountains of 3 to 5 inches, for the west-northwest facing slopes of
the Alaska Range of 4 to 7 inches, and also significantly higher
amounts across the higher terrain on the Seward Peninsula, of up
to 9 inches or locally more for a few areas. This will continue to
taper off going into the latter half of the weekend as colder and
drier air continue to advect in behind the exiting trough.

&&

.EXTENDED FORECAST DAYS 4-7...
Ensembles have overall shown persistence in terms of a strong
building of a ridge building in over the Bering/Chukchi Sea during
the early part of next week, while a strong upper level low pressure
is positioned over the Beaufort Sea/Canadian Archipelago, and
another upper level low being located in the Gulf of Alaska. Through
at least the first half of next week, the North Slope could see
multiple rounds of snow from a series of Arctic lows moving down
into the Beaufort Sea and either into the northeast Arctic coast, or
into the Canadian Archipelago. As these lows move into the area,
winds on the eastern Arctic coast could intermittently rise and lead
to blowing snow, and significantly reduced visibilities at times.
Elsewhere, a strong high-pressure ridge aloft is expected to set up
over the Bering Sea, with cold troughing over northwestern Canada,
which will allow for a very cold air mass to move down from the
north and over eastern Alaska. With the temperatures at 850 mb
falling into the mid to lower -20s C, surface temperatures from Mon
December 15 through at least Wed December 17 in much of Eastern and
parts of Central Alaska could reach into the -40s or even near -50F,
even outside of typical cold spots.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ801>803-806.
Winter Weather Advisory for AKZ847>850.
Winter Storm Watch for AKZ804-805.
Winter Weather Advisory for AKZ808>810.
PK...Brisk Wind Advisory for PKZ801.
Brisk Wind Advisory for PKZ802-803-808-852.
Brisk Wind Advisory for PKZ804-813-859.
Brisk Wind Advisory for PKZ805-809-855.
Gale Warning for PKZ806.
Gale Warning for PKZ807-856.
Gale Warning for PKZ810.
Gale Warning for PKZ811-857.
Gale Warning for PKZ812-858.
Brisk Wind Advisory for PKZ815-861.
Gale Warning for PKZ816-817.
Heavy Freezing Spray Warning for PKZ817.
Brisk Wind Advisory for PKZ850-853.
Heavy Freezing Spray Warning for PKZ851.
Gale Warning for PKZ851.
Gale Warning for PKZ854.
&&

$$

Stewey

516
FXAK67 PAJK 110011
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
311 PM AKST Wed Dec 10 2025

.SYNOPSIS...

Key Messages:

- Cold temperatures continue, with many areas seeing single
digits to teens for overnight lows. Northern Lynn Canal will
see lows below zero. Dangerously cold wind chills along White
Pass.

- Snow in the southern panhandle moves east late this afternoon
into early evening. Leaving behind clearer and drier skies for
the panhandle.

- Continued strong outflow winds will keep the cold air in place
through the weekend for the northern panhandle. Marginally
warmer air moves into the southern panhandle this weekend with
snow likely.

&&

.SHORT TERM.../through Thursday night/...Main concerns in the
short term is the continued well-below-normal temps and the snow
in the far southern panhandle.

For the snow in the south, the band of snow is tracking eastward
quickly so the snow will last through the rest of Thursday
afternoon into early Thursday evening with diminishing snow
overnight.

As far as the cold is concerned, cold weather products are issued
for the for northern Lynn Canal areas through Thursday night due
to wind chills getting down to -20 to -50. Elsewhere, low wind
chills are likely, just not to specific thresholds that are
unique to local areas. Low air temps down to singe digits to
teens for most of the area, little colder in Northern Lynn Canal.
Thursday`s high air temps look to be in the single digits for
Northern Lynn Canal, low to mid teens for the Icy Strait Corridor,
low 20s to near 30 for the rest of the panhandle.

Skies should remain dry with mostly clear conditions expected
into Friday.

.LONG TERM.../Friday through Monday/...Only minor changes were
made to the long term forecast, mainly adjusting outflow wind
timing and beginning to narrow down timing on the potential snow
for next weekend into early next week.

Strong outflow winds continue to hold any developing showers
offshore until Saturday morning, keeping the panhandle dry with
partly cloudy skies through the rest of the week. A small surface
ridge developing on Friday is expected to make that day the most
clear and the least windy, though outflow winds will still be
elevated to around 20 kts in the strongest areas. Precipitation is
expected to return to the forecast Saturday morning as a low
jumps into the southern gulf and sends a front northward into the
panhandle. The precipitation will mainly impact the southern
panhandle over the weekend, extending north to the central and
parts of the northern panhandle through Sunday into next week.
Uncertainty still remains in how far this front will make it up
the panhandle, as persisting outflow winds will attempt to force
the front to stay more south. With colder temperatures remaining
through the long term forecast, precipitation will most likely
fall as snow for the northern panhandle. The front will bring
slightly warmer temperatures around freezing with it to the
southern panhandle, making it possible for this precipitation to
mix for parts of the weekend. Active weather looks to remain into
early next week.

The main impacts for the long term remains the temperatures and
winds. The arctic boundary sits just south of the panhandle
through the rest of the week, keeping below freezing temperatures
through much of the extended forecast. Daytime highs will struggle
to reach into the 20s for many locations in the northern and
central panhandle, and into the 30s for the southern panhandle.
Overnight lows during the week will mostly stay in the single
digits up north and in the 10s down south, slightly increasing
through the weekend as the next system moves in. Uncertainty
remains on southern panhandle temperatures through the weekend, as
models are starting to depict the arctic boundary shifting just
north of this area allowing the front to bring temperatures in the
mid to upper 30s to some of these southern locations. This makes
snow potential even more uncertain, as there may be times where
these temperatures reach above freezing enough to turn to a
rain/snow mix or even just rain for periods. This boundary looks
to shift back down south into early next week, keeping the cold
temperature trend in the extended forecast. An extreme cold
warning for Skagway, primarily along the Klondike Highway, has
been reissued through 9 AM Friday for extremely cold wind chill
temperatures as low as 55 degrees below. The cold weather advisory
for the Haines Borough has also been reissued through 9 AM Friday
for wind chills as low as 25 degrees below, primarily once the
sun sets. Strong outflow also persists through the week, with 20
to 35 kt winds and pockets of gales blowing through the inner
channels and funneling out into the coastal waters of the gulf.
The strongest winds will remain in the northern panhandle,
particularly down Lynn Canal and Stephens Passage and out of Cross
Sound, with gaps along the gulf coast serving as outlets for
strong winds to funnel through. There will be a brief decrease in
wind speeds on Friday, though Lynn Canal will still stay above 20
kts before outflow ramps up even stronger than before going into
the weekend. Strong gales are expected to spread through a
majority of the inner channels, with strongest winds remaining in
those hot spots in the northern panhandle. Freezing spray will
remain an issue in the inner channels and along the NE gulf coast
with these elevated winds, which could become heavy at times.

&&

.AVIATION...The strong northerly outflow continues overnight with
VFR expected central and north with MVFR going VFR by morning
across the south. For the northern airports, main concern in the
short term at Juneau were a bit of low level wind shear is
possible where we have southeast winds 10 kts on the runway then
winds at the 2 thousand agl level out of the northeast at 30-40
kts. Sheep Mountain last hour reported 50-60 kt winds out of the
northeast (an observation often of interest to pilots on approach
into and departing out of Juneau). Otherwise, low ceilings and
bands of light snow will moving through the Ketchikan and
Metlakatla areas will keep MVFR going there for a few more hours,
but satellite imagery and higher resolution models show the snow
moving out to the east with ceilings expected to start lifting
late tonight and VFR expected by morning.


&&

.MARINE...
Outside Waters: Northeasterly outflow winds up to 30 to 35 kt are
in store for the northeastern gulf through Thursday. For Friday,
the pressure gradient relaxes & winds decrease. Then, outflow gap
winds increase again, up to around 40-45 kt, for the same areas
for the weekend. Significant wave heights increase to around 22
ft for the weekend. Some freezing spray is possible for the
northeastern gulf.

Inside Waters: The outflow pattern continues for the next several
days, keeping up to around 30 to 40 kt sustained winds for the
northern 2/3 of the Inner Channels with the strongest winds in
Northern Lynn Canal. These winds will also be accompanied by
fully-developed seas up to around 17 ft with the highest waves
the more northward you go. Additionally, moderate to heavy
freezing spray is also likely to continue.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Extreme Cold Warning until 9 AM AKST Friday for AKZ318.
Cold Weather Advisory until 9 AM AKST Friday for AKZ319.
Winter Weather Advisory until 6 PM AKST this evening for AKZ330-
332.
MARINE...Heavy Freezing Spray Warning for PKZ011-053.
Heavy Freezing Spray Warning for PKZ012-013-031.
Gale Warning for PKZ012-013-021-031-034-651.
Small Craft Advisory for PKZ011-022-032-033-053-641>644-652-
661>664-671-672.

&&

$$

SHORT TERM...GJS
LONG TERM...ZTK
AVIATION...JG
MARINE...GJS

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