Graphical Hydro Meteorological Discussion

668
FXAK68 PAFC 311334
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
434 AM AKST Wed Dec 31 2025

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

An amplified ridge is located over the Bering Sea this morning
with broad upper level troughing located across the interior
portions of Alaska mainland and the Gulf of Alaska. Northerly flow
prevails across southwest Alaska and the western Gulf. A stacked
low is located near Yakutat and an embedded trough is bringing
light snow to portions of the Copper River Basin south to the
Prince William Sound communities and the Cordova area.

With gusty winds through the coastal mountain gaps, low
visibilities may continue through this morning, until the
transportable snow is mostly scoured out. While the strongest area
of cold advection will be across the Alaska Peninsula, the
western Gulf coastal waters, and Kodiak Island, cold air deepens
across the rest of Southcentral as well, so gap winds look to ramp
up again through today. The Matanuska Valley could have some gusty
winds this afternoon, up to 45 mph in the afternoon and decreasing
later tonight. Gusty winds, already ongoing through Thompson
Pass, are also expected to reduce visibility to one half mile or
less with snow. Visibility is expected to improve as snow comes to
an end across Prince William Sound and the Copper Basin this
evening. In all, snow accumulations up to around 3 inches are
expected near the coast, with decreasing amounts further
inland/north.

Then, dry and cold conditions will settle back in across the
region. Gap winds will begin to gradually diminish Thursday into
Friday with the loss of the upper-level forcing from the trough.
Meanwhile, temperatures will gradually trend downward into the
weekend. We are monitoring the potential for wind chills 40 below
zero or lower developing across the Copper Basin and mountain
passes of the Alaska Range as early as tonight. By Friday,
ambient temperatures in the single digits above and below zero are
expected across the Cook Inlet region (Anchorage, western Kenai,
Mat-Su) and even much of the north Gulf coast (including Seward,
Whittier, Valdez, and Cordova). Meanwhile, the Copper Basin will
likely be in the range of 20 to 30 below zero. Any bit of wind
would drop the apparent temperatures lower. This cold looks to
stick around through Monday next week.

Quesada/Rux

&&


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

An upper level ridge moving over the central Bering Sea is now
slightly losing amplitude as an incoming North Pacific low and
leading front moving into the western Aleutians begin to erode the
ridge from the west. Strong northwesterly flow between the ridge
and a low drifting over the eastern Gulf continues across the
AKPen. Gusty gap winds along and south of the Pacific side of the
AKPen are finally dipping below Storm force as both the Bering
ridge and Gulf low steadily begin to weaken. Farther north, snow
showers are clearing out this morning behind the passage of a weak
front across the Kuskokwim Delta. Areas of low stratus have
spread in behind the front, mainly over and to the west of the
Kuskokwim Mountains. Mostly clear and cold conditions in the -0s
to -10s persist across the Lower Kuskokwim Delta and Bristol Bay,
while warmer temperatures in the 10s to low 20s have moved in
along the coast near and northwest of Togiak.

Looking to the forecast, the front currently moving into the
southwest corner of the the Bering is on track to continue
northeast across the Bering and Aleutian Chain as areas of rain
and south winds just under Gale force continue to follow the
boundary. The front will reach the Pribilofs by this evening,
with a rain/snow mix possible at precipitation onset before warmer
air moving in with the front quickly changes everything over to
all rain. The most noteworthy change for this system is that it
now looks more likely for the front to advance a bit farther
north, likely falling just short of the Southwest Coast before it
begins to stall and weaken. Light snow now looks more likely to
spread into much of the Kuskokwim Delta, especially along the
coast, where around 2 to 3 inches of new snowfall is likely
between Thursday morning and Friday morning. East winds along the
front will be weakening as it arrives on Thursday, but could still
be strong enough to cause areas of blowing snow and reduced
visibilities along the Kuskokwim Delta Coast as falling snow move
in. Farther south, gusty northwest winds along and south of the
AKPen will quickly diminish Thursday as the synoptic support
fizzles.

Looking back to the west and towards the end of the week, a shift
to a more progressive and active pattern is becoming more
apparent. A potent, compact shortwave and low will move into the
southwestern Bering on Thursday, sending a small pocket of Gale to
Storm force winds across parts of the western Aleutians along with
another quick round of rain. The low will weaken as it heads
rapidly east on Thursday night, perhaps clipping the Pribilofs
with a bit of rain as it passes to the south. Another shortwave
and frontal system will move in quickly behind the compact low,
spreading more gusty winds and light rain into the Aleutian Chain
on Friday. This increasingly active pattern will likely continue
into the weekend.

-AS

&&


.LONG TERM FORECAST (Days 4 through 7: Friday through Monday)...

Very cold, dry weather will persist into the weekend across mainland
Alaska, while the Aleutians remain near- or just above-average in
terms of temperatures thanks to a strong amplified upper-level ridge
that remains in place across the central Bering Sea. Models are
beginning to converge to a solution which features a deep low
crossing over the Aleutians and into the Bering late Saturday into
Sunday, helping shift that large ridge eastward a bit. Strong winds,
large waves, and heavy precipitation are all a possibility with this
low as it shifts north, with the strongest winds currently expected
to be from approximately Atka west.

For Southcentral, the main hazard for the weekend will be the
continuation of strong gap winds through Sunday before the pressure
gradient relaxes. Temperatures will be quite cold, with highs near 0
for Anchorage and the Kenai Peninsula, with lows closer to 10 below.
The Copper River Basin will remain frigid, with temperatures largely
hovering between 20 and 40 below.

Models diverge, and thus confidence lowers, as we head into the
beginning of next week. There`s still reasonable consensus that a
strong front associated with this low will rotate east into mainland
Alaska, helping break down the ridge that would then be across the
Gulf of Alaska north. A strong triple point low may also develop
across the northern Gulf, which would bring heavy precip/snow to
much of the Southcentral Coast. Details are still murky with this
one, but this would ultimately be the next chance of significant
snow accumulation for much of the area. Stay tuned.

&&


.AVIATION...

PANC... VFR conditions will persist through the TAF period.
Northerly winds on the order of 5 to 10 kts this morning will
slowly increase to 10 to 15 kts by 00z, with gusts as high as 20
to 25 kts later this evening.

-AM

&&


$$

837
FXAK69 PAFG 311144
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
244 AM AKST Wed Dec 31 2025

.SYNOPSIS...
Cold weather continues through the weekend. Gusty winds and light
snow brings low visibility to the Eastern North Slope including
the Dalton Highway corridor and Eastern Arctic Coast Wednesday
through Thursday. Generally clear and calm conditions across the
Interior will allow valley temperatures that recently warmed to
rapidly cool once more. Possible warmup early next week as a low
pressure system brings warmer, wetter air towards Alaska.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Persistent cold weather in the Interior remains with temperatures
well below normal for the foreseeable future.

- Widespread 30s/40s below or colder where there are clear skies.
Possible -50s in the coldest spots.

- Most cloud cover moves northeast by this weekend leaving much of
the Interior clear and calm.
- Most extreme temperatures will be in the Eastern Interior
Valleys where temperatures near 60 below zero will be possible.
- Central Interior Temperatures may get near 50F below zero or
colder.

- A long term cold weather advisory has been issued for the
Fairbanks North Star Borough and Nenana with temperatures
consistently down from 40 to 50 below and some of the coldest
spots potentially reaching below -50. Patchy ice fog is already
beginning to redevelop around the Fairbanks area and is likely
to continue to build through the end of the week.

West Coast and Western Interior...
- Snow and gusty wind through the Bering Strait and along the
Seward Peninsula diminish through Wednesday morning.
- Low visibility to as low as 1/4 mile through the Bering
Strait rapidly improve Wednesday morning.

- Temperatures gradually cool through the end of the week falling
to the teens/20s below zero along the coast and widespread 40s
below zero in Interior valleys.
- The warmest temperatures are expected along the Yukon Delta
and St. Lawrence Island in the single digits above and below.

North Slope and Brooks Range..
- Light snow and flurries from the northern slopes of the Brooks
Range to the Arctic Coast through Wednesday night.
- Remaining snowfall expected east of Point Barrow with 1 to 2
inches possible along the Dalton Highway corridor and up to 1
possible along the Arctic Coast.

- Wind increases with northerly winds through Atigun and Anaktuvuk
Passes around 35 mph Wednesday through Thursday morning. A
winter weather advisory has been issued for blowing snow
reducing visibility to 1/2 mile or less at times.

- Wind in Kaktovik will also increase Wednesday evening and
continue through Thursday evening with gusts to 50 mph. A
blizzard warning has been issued with visibility down to 1/4 of
a mile or less at times.

&&

.FORECAST ANALYSIS AND DISCUSSION...
For Wednesday through Friday night.
At the start of the forecast period Wednesday morning, broad
troughing is set across Alaska extending from a 495 decameter
upper level low over the North Pole south to a 519 decameter low
in the Gulf of Alaska and even further to a 534 decameter low in
the North Pacific. This trough is allowing very cold Arctic air to
settle over the state creating high surface pressures despite the
upper level troughing. Generally clear and calm conditions as this
cold air settles over the Interior will allow for very strong
temperature inversions to form. Should this persist for long
enough many communities around the Interior could see the
development of ice fog as water vapor from vehicles and heating
systems gets stuck near the surface and accumulates. Fairbanks
will likely see the redevelopment of dense ice fog first simply
due to its larger population producing more local sources of water
vapor.

A 555 decameter ridge is set in the Eastern Bering Sea and
effectively blocks the movement of lows that could potentially
disrupt this cold. The ridge has been weakening over the course of
the past week due to a series of weak lows that have moved across
the state. The latest of which is still producing some light snow
and gusty winds around the Seward Peninsula. These conditions will
end Wednesday morning as the low rapidly weakens against the high
surface pressure. Until this ridge breaks down, the cold
conditions across the state are expected to continue with the
occasional brief warmup as a low rides over the top of the ridge.


&&

.EXTENDED FORECAST DAYS 4-7...
For Saturday through next Wednesday.
Cold conditions continue at the start of the extended forecast
period and through the weekend. The best chance for a warmup in
the current forecast comes as a stronger low enters the Western
Bering Sea. There is still some uncertainty in the strength and
position of this low but even the weaker estimates would likely be
strong enough to break down what remains of the Bering Sea ridge,
allowing some warmer, wetter, more southerly air to reach into
Northern Alaska Monday into Wednesday. As with most ridge
breakdown events forecast confidence is not very high. Models have
difficulties accurately timing ridge breakdown, especially in
regions with sparse observations like Alaska, but much of that
uncertainty will be in regards to timing and distribution of
potential snowfall. A warmup is likely for the region when this
low breaks down the ridge.

Coastal Hazard Potential Days 3 and 4...None


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Blizzard Warning for AKZ820-821.
Winter Weather Advisory for AKZ804-808-809.
Cold Weather Advisory for AKZ838>845.
Blizzard Warning for AKZ805.
PK...Brisk Wind Advisory for PKZ801-802.
Brisk Wind Advisory for PKZ805.
Gale Warning for PKZ806-807-856.
Brisk Wind Advisory for PKZ808-809-855.
Brisk Wind Advisory for PKZ810.
Brisk Wind Advisory for PKZ811-857.
Brisk Wind Advisory for PKZ814-860-861.
Gale Warning for PKZ815.
Small Craft Advisory for PKZ816-817.
Heavy Freezing Spray Warning for PKZ816-817-851-854.
Brisk Wind Advisory for PKZ850.
Gale Warning for PKZ851.
Brisk Wind Advisory for PKZ853.
Gale Warning for PKZ854.
&&

$$

Stokes

721
FXAK67 PAJK 311610
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
710 AM AKST Wed Dec 31 2025

.SYNOPSIS...

Key Messages:

- Winter storm continues in Northern Southeast Alaska with snow
showers continuing through early Wednesday.

- Localized flooding from streams over the southern panhandle.

- Offshore flow with break in snowfall looks to come for the
panhandle into the end of the week through the early weekend.


&&

.SHORT TERM...
A low pressure system remains in the northeastern
Gulf of Alaska sending showers over the panhandle. Precipitation
rates have greatly diminished overnight, but times of moderate snow
showers will continue this morning. With continued snow showers, the
Winter Storm Warnings for the northern panhandle remain in place
until noon. At that time, snow amounts and rates are expected to
greatly diminish with snow eventually ending late tonight into
Thursday.

Although rain showers have greatly diminished over the southern
panhandle, the Flood Advisory for Ward Lake areas below Lake Connell
Dam remains in place due to continued runoff and high water levels.
With precipitation subsiding this advisory is expected to end later
today, but we will continue to monitor the situation and water
levels.

Lastly, winds will decrease throughout the day as the low in the
gulf weakens. The strongest land winds will continue to be near
Skagway where gusts of 35 to 40 mph continue this morning. These
winds will diminish this afternoon, but will once again start to
increase tonight into Thursday as weak northerly outflow once again
starts.

.LONG TERM...End of the week into the start of the weekend is
generally on a cooler and drier trend, with diminishing chances
for snowfall.

Going into the end of the week, an upper level trough moving
eastward will sit over the panhandle, blocking off some of the
moisture from moving in despite the low lingering in the northern
Gulf, and allowing for arctic air to be brought down into the
panhandle. The setup will change to more of an outflow pattern as
northerly winds last into the weekend, and cooler and drier air is
brought down into the panhandle from the Yukon. Temperatures will
steadily decrease across the panhandle Wednesday through
Saturday, however the weaker outflow setup will not allow for
quite as cold conditions as we have seen earlier this month, with
minimum temperatures staying largely above 10-15 degrees with the
exception of the far northern panhandle seeing colder conditions.
Temperatures will decrease to the low to to mid 30s for the
southern panhandle and central outer coastline by the end of the
week, to the low to mid 20s for the central panhandle, and to the
mid teens to less than 10 degrees for the far northern panhandle
by Friday. These colder temperatures and drops in snow level will
last into the weekend before the next system moves into the Gulf,
with warmer temperatures and moisture returning to the panhandle
by Monday as this next system brings in the next round of
snowfall.

Overall during this period, precipitation chances will drop across
the panhandle as the moisture is cut off, with only some slight
chances during the end of the week. The highest chances remain
along the northern Gulf coast and the far southern panhandle,
though some weak showers may move through the panhandle from the
low weakening in the northern Gulf. Any precipitation that happens
will remain largely light and short lasting showers, due to the
lack of moisture and weakened dynamic setup. Either way this
period of time is expected to be a break in the snowy weather,
with the majority of the panhandle expecting to see drier and even
potentially sunny conditions as skies clear with the offshore
flow that sets up by the end of the week.

&&

.AVIATION.../Until 12Z Thursday/...For the northern panhandle,
expect primarily MVFR conditions with dips into IFR from snow
showers for the first part of the period. For southern areas,
expect mainly MVFR conditions in the morning with rain showers,
improving to VFR toward as we progress through the period. It will
stay breezy for Lynn Canal, including PAGY & PAHN, through the
period & also the central Outer Coast, including PASI, into the
afternoon hours. LLWS magnitudes of up to around 35 kt are
expected for the Outer Coast, including PAYA, PASI, & PAKW, and
the PAJN area through the day today.

&&

.MARINE...
Inside (Inner Channels): Northerly outflow winds up to 25-30 kt
will be impacting Lynn Canal & Stephens Passage through the week.
Winds will be up to 15-20 kt elsewhere in the Inner Channels.
Significant wave heights of up to around 6 ft with the highest
values in northern areas like Lynn Canal & Stephens Passage are
also expected. Higher seas are anticipated near ocean entrances.

Outside (Gulf and Coastal Waters): A low out in the northern Gulf
will persist through midweek, bringing fresh to strong breezes.
10-15 ft waves are expected to continue with the predominant
swell direction remaining out of the south and west. Winds and
seas diminish through the latter half of the week as the low
weakens.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning until noon AKST today for AKZ318>320-325.
Winter Weather Advisory until 6 AM AKST early this morning for
AKZ321-322.
MARINE...Small Craft Advisory for PKZ012-013-022-031-034-053-641>644-651-
652-661>664-671-672.

&&

$$

SHORT TERM...EAB
LONG TERM...Contino
AVIATION...JLC
MARINE...JLC/BMB

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