Graphical Hydro Meteorological Discussion

514
FXAK68 PAFC 061428
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
528 AM AKST Sat Dec 6 2025

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

Key Points:

Weather continues to remain active across Southcentral Alaska with
the threats of snow, blowing snow, strong winds, and dangerously low
wind chills through the end of the weekend.

...Active Warnings and Advisories...

- A Winter Weather Advisory has been issued for Northeast Kodiak
Island from 3PM this afternoon to 3PM Sunday for 3 to 5 inches of
snow and blowing snow. Winds gusting up to 55 mph are possible for
the northern side of the island and up to 40 mph for Kodiak City.

- A High Wind Warning remains in effect for the Matanuska Valley
through 11PM Sunday for 30 to 40 mph winds with gusts up to 80 mph.

- A Wind Advisory remains in effect for Anchorage and the NW Kenai
Peninsula through 11PM Sunday. North winds of 20 to 30 mph with
gusts to 50 mph expected. Strongest winds expected along the Knik
Arm and West Anchorage and out along the coast of the northern Gulf
coast.

- A Blizzard Warning remains in effect for Thompson Pass until 6AM
Sunday for blizzard conditions and 5 to 10 inches of snow. Winds
could gust as high as 60 mph. Wind chills falling to as low as 35
below zero by Sunday morning.

- A Blizzard Warning remains in effect for Broad Pass, Richardson
Highway from south of Isabel Pass to Paxson, and along the Tok
Cutoff from Mentasta Pass to north of Gakona through 9PM Sunday due
to blowing snow with winds gusting to 50 mph. Wind chills dip as low
as 15 to 25 degrees below zero, falling further to 25 to 40 degrees
below zero by Sunday.

- A Winter Weather Advisory remains in effect for the Copper River
Basin until 5PM Saturday for 2 to 5 inches of snow and blowing snow.
The lowest totals will be west of Glennallen, and the highest
totals will be south and east of Glennallen.

Discussion:

The weather over Southcentral for the foreseeable future will be
focused on the cold Arctic airmass now in place, strong gap winds,
and blowing snow leading to reduced visibilities through many of the
mountain passes. The Arctic airmass has pushed all the way to the
Gulf with coastal areas, and even Middleton Island seeing
temperatures down into the lower 30s. For inland Southcentral,
temperatures this morning are ranging from the minus single digits
to minus teens across northern Susitna Valley and the northern
Copper River Basin. With these cold temperatures, dangerous wind
chills of minus 20 to minus 30 have developed over these northern
zones. Further south, strong winds through the Matanuska Valley and
down the Knik Arm and Cook Inlet have resulted in warmer
temperatures in the teens and 20s with wind chills of near zero. The
Matanuska, Knik, and Valdez winds (including Thompson Pass) quickly
increased during the overnight hours with winds in Palmer and
Thompson Pass reaching 70 mph this morning. This has led to blowing
snow for the lower Matanuska Valley and Knik Arm, and ongoing
blizzard conditions in Thompson Pass. Strong winds will continue
through the weekend with a brief dip tonight before increasing again
Sunday. As such, the High Wind Warning and Wind Advisory remain in
effect for the Matanuska Valley, Knik Arm, and down the western
Kenai. Snow will start winding down for Thompson Pass and southern
Copper Basin today, but strong winds will continue through the pass
with possible ground blizzard and dangerous wind chill conditions
through Sunday morning.

The low over the northern Gulf will retrograde southwestwards this
afternoon with surface low progged to pass to the east of Kodiak
Island. Models are in good agreement that snow will spread into the
northern half of the island beginning this afternoon and continuing
through Sunday afternoon. Strong northerly winds have allowed
temperatures to drop into the lower 30s and with the vertical
profile below freezing, precipitation type should be all snow. The
question will be on amounts given the predominantly northerly winds
for the lee-side areas like Kodiak City. There is a chance that
winds could turn more northeasterly into Kodiak City and bump up
snowfall totals. For now, lower elevations could see several inches
of snowfall. Winds will be the other concern for the island as gusts
could reach 55 mph on the northwest side of the island. This will
lead to blowing snow concerns. As such, a Winter Weather Advisory
has been issued for the northern half of the island for snow of 3 to
6 inches and blowing snow.

The Gulf low will start to get squished then forced eastwards early
next week as a strong Arctic high drops into the western Bering Sea.
Another reinforcing push of Arctic air looks likely heading into the
middle of next week.

- PP

&&


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

Very little has changed with the short term forecast. Gusty winds
and very cold temperatures expected across much of the mainland
with snow showers along the Aleutians and Alaska Peninsula regions
this weekend. Strong winds in the Kuskokwim Delta may loft snow
on the ground from the previous weather event from Kipnuk north
and west and north and west of Bethel during the weekend. Due to
the threat of blowing snow, a Blizzard Warning is in effect for
the aforementioned regions. Also, the very cold air will move over
considerably warmer ocean temperatures (30s), leading to numerous
snow showers over the Eastern Aleutians and the Alaska Peninsula
today and the rest of the Aleutians Sunday. This, combined with
strong winds could lead to blowing snow and low visibility. A
Winter Weather Advisory has been issued for the Alaska Peninsula
due to this potential for blowing snow. Another threat with the
cold and winds is wind chill. The Kuskokwim regions could see wind
chills 35F below zero for a period. Bristol Bay will see wind
chills from 20F to 30F below zero, especially in the Dillingham
region. A Wind Advisory as been issued for the Dillingham area
highlighting the gusty winds and wind chill threat this weekend.

High pressure will set up over Southwest Alaska and most of the
Bering Sea/Aleutians early next week. This will keep the cold air
mass in place and set up drier conditions overall. Winds will
diminish through Monday as well. Models are hinting at the next
front/low combinations entering the Western Bering/Aleutians
Wednesday morning. Model uncertainty remains high for how the
front will track across the Bering Sea.

&&


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

The long-term pattern will favor mostly quiet conditions across
the Southern Mainland. However, gusty gap winds will continue to
filter through the favored terrain and gaps as a cold airmass
looks to linger across the area. This is especially true for the
gaps across Southcentral such as Seward, Valdez Narrows, Whittier,
Thompson Pass, and the Matanuska Valley. Where some active
weather will occur will be across the southern Alaska Peninsula
and Eastern Aleutians as a shortwave drives southward from Siberia
to over the area Wednesday. This weak system could bring brief
visibility reduction with snow showers moving from north to south
off the Bering Sea. Also on Wednesday, a Kamchatka low sends a
front eastward across the Western Aleutians bring a round of gusty
southeast winds and gale-force winds across the marine zones of
the Western Aleutians. This front weakens as it moves eastward
through Friday. There is still some uncertainty on the eastward
progression due to the strength and progression of a broad ridge
over much of the Bering and mainland Southwest Alaska.

&&

.AVIATION...

PANC...VFR conditions will persist through the afternoon today.
Northerly winds coming out of the Matanuska Valley will continue,
just clipping the terminal. Expect speeds generally around 20 kts
gusting to 35 kts through the TAF period, however gusts may
occasionally increase to 40-45 kts.

&&


$$

180
FXAK69 PAFG 062201
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
101 PM AKST Sat Dec 6 2025

.SYNOPSIS...
Cold and windy conditions continue across the Interior through
Sunday. Winds decrease rapidly Monday, but cold temperatures
remain. Mostly clear and dry weather expected through the week,
except for Monday and Tuesday along the North Slope where a weak
front brings some clouds and snow chances across the Arctic Coast.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Areas of stratus clouds are diminishing in coverage, allowing
valley temperatures to drop into the 20s and 30s below zero with
a few 40F below zero readings.

- Cold and windy this weekend for most of the Interior.
- N/NE wind increases significantly Saturday from the Yukon
Flats southwest. Gusts above 1000ft may be upwards of 30 to 50
mph whereas valleys can see gusts up to 35 mph (WHEN the
inversion breaks). This continues into Sunday PM, then
weakens.
- Ambient temperatures through Sunday, with no clouds or wind,
between 20F to 40F below zero. A few colder spots, especially
north and east of Fairbanks may hit 45F below. Valley
temperatures may increase with winds, but wind chills of -40
to -60 are expected when these winds reach valley floors.
- Wind chill values of 40 to 60 below zero from Tanana to the
Yukon Flats this weekend. Significant blowing snow is expected
in the higher terrain above 1500ft. Periods of blizzard
conditions are expected along portions of the Steese/Dalton
Highway Summits and along the southern slopes of the AK Range.
- This could be a significant wind event and end up being
impactful as it could lead to tree damage and power outages.

- Colder and calm weather prevails next week with minimum
temperatures dropping between 30F and 50F below zero. A few
colder spots in the Yukon Tanana Uplands (like Chicken) may
approach 50F below zero.

West Coast and Western Interior...
- A cold trend continues through the weekend. Expect minimum
temperatures in the single digits above and below 0 along the
coast and in the teens to 30s below zero in the Interior
Valleys.

- North-northeast winds increase today. Wind gusts may be up to 30
to 40 mph along the coast from the Seward Peninsula south.

- Winter weather advisories have been issued for the Middle to
Lower Yukon Valleys and the Eastern Norton Sound for blowing
snow and dangerous wind chills. Gusts of 35 to 50 mph could lead
to periods of blowing snow and wind chills as low as 50F below
zero.

- Blizzard warnings for the Upper Kuskokwim and Western Alaska
Range have been downgraded to Winter Weather Advisories. The
snowpack was not as blowable as initially expected and prolonged
periods of blowing snow are no longer expected. Dangerous wind
chills remain a threat with wind gusts of 30 to 50 mph that
could lead to wind chills as low as 50F below zero.

- Winds weaken Monday and temperatures decrease again next week.
Lows potentially in the 30s/40s below zero in the Interior and
single digits/teens below zero along the coast.

North Slope and Brooks Range..
- Most of the light snow chances have ended. There is another
chance for light snow Monday night into Tuesday as a front
approaches. Up to 1 inch of snow is possible.

- Widespread temps in the 20s and 30s below zero with some 40F
below readings possible.

- Northerly winds increase today up to 10 to 15 mph along the
coast and up to 25 to 35 mph through Brooks Range passes. Wind
chills fall to as cold as -60F through the Brooks Range passes.

- Wind diminishes Sunday with a warming trend into the early part
of next week as clouds increase in coverage with chances for
snow.

&&

.FORECAST ANALYSIS AND DISCUSSION...
For Saturday through Tuesday.
At the start of the forecast period Saturday, a strong 553
decameter upper level high and a 501 decameter upper level low are
creating a very strong jet of winds aloft over the region. This
jet of strong winds is creating strong gusts near the surface
which, when combined with the very cold temperatures (-22C to -32C
at 850mb) is creating areas of dangerous wind chills. This
pattern is additionally very dry and has left most of the Interior
completely clear. Strong temperature inversions in the valleys
and the very stable and cold air within them is limiting the
strongest winds from completely reaching valley floors. Clear
conditions and very low sun angles encourages the formation of
strong inversions and winds threaten to mix out these inversions.
At higher elevations, gusty conditions prevail, but the ambient
temperatures aren`t quite as cold. Dangerous wind chills are still
a threat however, as well as the potential for areas of low
visibility due to blowing snow. This snow would be from the snow
seen earlier in the week across the Interior as we are too dry to
produce any new snow where the strongest winds are.

This windy pattern lasts through Sunday, although slowly weakens
as the high and low even out slightly. Sunday night through
Monday winds decrease rapidly bringing the region to mostly calm
conditions by late Monday. The wind chill threat will end, but
ambient temperatures in Interior Valleys will once again decrease
into the -30F to -45F range with the coldest spots potentially
reaching as low as -55F. Clearer and calmer conditions persist
through most of the region through Friday, except for the North
Slope where a weak shortwave feature rotating through the
weakening high and low pattern will pass over the area Monday into
Tuesday bringing clouds and the chance for light snow.

&&

.EXTENDED FORECAST DAYS 4-7...
For Tuesday night through next Saturday.
At the start of the extended forecast period Tuesday night, a
strong ridging pattern extends over the Bering Sea and weak
troughing sits over the Eastern portion of the state. This ridge
acts as a shield for the Interior deflecting lows attempting to
move into the region to the south or north. Model agreement is low
on exactly how each weaker low pressure system moves as it
interacts with the higher pressure ridge, but this feature will
likely keep the region below our normal temperatures through the
end of next week. There is however a chance that a strong enough
low could try and move over the top of the ridge pattern and
actually make it into Northern Alaska. Should this happen it could
push out the cold air that has settled over the region and lead to
a period of warmer, cloudier conditions with chances of snow.
Otherwise cold and dry conditions will dominate the state through
the end of next week.

Coastal Hazard Potential Days 3 and 4...None


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Cold Weather Advisory for AKZ809>811.
Blizzard Warning for AKZ848-850.
Winter Weather Advisory for AKZ824-829-830-851-852.
Blizzard Warning for AKZ832-834.
Cold Weather Advisory for AKZ833-838>847.
PK...Gale Warning for PKZ801-802.
Brisk Wind Advisory for PKZ803-804.
Gale Warning for PKZ805-852.
Brisk Wind Advisory for PKZ816-817.
Gale Warning for PKZ850.
Heavy Freezing Spray Warning for PKZ851.
Small Craft Advisory for PKZ851.
Brisk Wind Advisory for PKZ853.
Brisk Wind Advisory for PKZ854.
&&

$$

Stokes

699
FXAK67 PAJK 061858
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
958 AM AKST Sat Dec 6 2025

.UPDATE...Morning update and 18z Aviation Update... The arctic
boundary moving down from the Yukon has pushed south quicker than
initially forecast Saturday. Winds in Lynn Canal have been
consistently out of the north as a low pressure center moved
inland over the central panhandle overnight, preventing any sort
of warm southerly push making it to Haines and Skagway. As of 9am,
the boundary has made its way down to Icy Strait, with Juneau and
Gustavus seeing accumulating snow, and temperatures hovering
right around freezing. With the boundary in place, areas that have
seen a transition to snow will likely stay that way going
forward. A Winter Storm Warning remains in effect for Haines and
Skagway, and a Winter Weather Advisory remains in effect for
Yakutat. Stay tuned for further updates on the Winter Storm Watch
still in effect for the Icy Strait Corridor.

&&

.SYNOPSIS...

Key Messages:

- Low pressure system in the Gulf brings a front eastward across
the panhandle through Saturday, bringing moderate to heavy
snow to the northern panhandle and moderate to heavy rain for
the southern panhandle.

- This weekend through next week, models continue falling into
line behind a weather pattern that has been known to produce
heavy snow. Higher confidence in totals for the northern
panhandle, but still some uncertainty remains about timing and
amounts as cold air pushes southward.

&&

.SHORT TERM...
The groundwork is in place for a significant snow event over the
next few days for the northern panhandle and Icy Strait Corridor.
The bulk of the forecast remains on track, and the main forecast
changes made overnight were to speed up the timing of the
rain/snow changeover in Juneau, and to increase snow ratios across
the northern panhandle as northerly outflow winds look to
successfully push the arctic boundary southward a bit faster than
anticipated.

A low pressure system moving across the central panhandle has
sent a front racing across the panhandle, bringing with it
moderate to heavy rainfall rates and elevated wind speeds. The
strongest winds and greatest rainfall rates look to be across the
northern half of the panhandle, with an inch to an inch and a
half of rainfall expected on Saturday. The system will be
reinforced Saturday night by a developing shortwave, before
stalling through the remainder of the weekend, and continuing to
funnel consistent moisture and strong winds into the panhandle. An
area of deep upper level troughing is shifting over the
panhandle, bringing colder temperatures and increasing outflow
winds through the weekend and into next week. These cold
temperatures steadily move southward through this period, and in
combination with the abundance of available moisture,
precipitation will changeover to snow.

Communities in the far northern panhandle have already firmly made
the changeover to snow, with temperatures in the 20s, and looking
set to continue falling through the forecast period. A winter
storm warning was issued for heavy snow accumulation in Skagway
and Haines through Sunday, with the greatest accumulations and
heaviest rates expected to fall on the higher elevations of the
Klondike and Haines Highways. Consistent moderate to heavy
snowfall is looking to bring accumulations of between 18 and 28
inches to Skagway and 15 to 22 inches to the Haines Borough, with
the higher amounts expected at higher elevations of the highways.
For Skagway at sea level and along the highway, and from Haines
down along the Chilkat Peninsula, wind gusts up to 45 mph are
possible Sunday which may result in some blowing snow following
the fresh snowfall. Yakutat is also seeing snowfall and will see
accumulating advisory level totals of around 3 to 5 inches
through Saturday. Confidence continues to grow in the Icy Strait
Corridor, including the cities of Gustavus, Hoonah, Tenakee
Springs, Elfin Cove, Pelican, and Juneau seeing significant
snowfall accumulations starting Saturday night into Sunday. A
watch has been issued for potentially heavy snow from Sunday
morning into Monday night, with accumulations between 11 to 16
inches possible. Given the strong northerly outflow winds which
are already establishing themselves in Lynn Canal, it is possible
that this time table may be pushed up, with a rain snow mix
possible during the daytime hours, and accumulating snow for some
locations along the Icy Strait Corridor as early as Saturday
night. Cold temperatures will continue to drop southward into the
central panhandle as another system advances from the south,
sending another front with similar rain rates into the southern
panhandle. The pattern continues to persist through the long term,
increasing confidence of a long duration snow and rain event. See
the long term for more information on how this pattern will
continue into next week.

.LONG TERM.../Sunday to Tuesday/...
The arctic boundary continues to move southward with the
northerly outflow trying to set up. Expect snow to develop Sunday
from Pelican-Elfin Cove east towards Juneau ( the Icy Strait
Corridor) and continue through much of Monday to Tuesday.
Significant snowfall may fall Sunday to Monday evening, so a watch
has been issued.

Cold air will continue to push south Tuesday, and spread the snow
into the southern panhandle by Tuesday, with another system
arriving and expected to target the southern and possibly central
panhandle. Meanwhile, building outflow winds will lead to drying
and windy conditions across the northern panhandle, which will
spread south to the rest of the SE AK by Wednesday, bringing with
them sharply colder temperatures.

Gusty north winds from the outflow, with gusty winds to 40 to 45
mph perhaps so possibly blowing snow, if snow characteristics are
right, or freezing spray down Lynn Canal.

&&

.AVIATION.../through Sunday morning/...Arctic boundary pushed
south a bit quicker than originally forecast, leading to
conditions deteriorating along the Icy Strait Corridor by mid
morning to IFR due to a transition to primarily snow. Areas that
have seen a transition to snow will likely stay that way, meaning
any precipitation will lead to significant drops in VIS. Otherwise
generally MVFR flight conditions south of the Icy Strait Corridor
with IFR to occasional LIFR flight conditions for PAYA, PAGY and
PAHN where moderate to heavy snow is still ongoing. Down south,
precip is likely to stay all rain through Saturday night, but VIS
and CIGs may still drop down to IFR flight conditions under
heavier rainfall.

Strongest winds will be across the northern panhandle near PAGY
and PAHN, increasing to 15 to 25kts with gusts 30 to 35kts, with
blowing snow likely. Elsewhere, winds becoming 10 to 18kts with
gusts 20 to 25kts. LLWS likely as well with winds 2kft aloft
becoming 30 to 40kts.

&&

.MARINE...
Outside Waters: Winds have shifted south southwesterly and
increased to fresh to strong breeze (17 to 27 kt) across the gulf
this morning. These stronger winds will last through Saturday. As
the pressure gradient tightens between the low in the Gulf and
the high to the north over Canada Saturday night into Sunday,
northeasterly near gale to gale force (30 to 40 kt) offshore winds
and gap winds will occur along the NE Gulf Coast between Yakutat
Bay and Cape Spencer. The southeastern Gulf will also see an
increase from near gales to gales (28 to 36 kt) as a front moves
through Saturday night into Sunday morning and again Sunday night
into Monday. Building seas will reach between 10 and 14 ft. The
seas will continue to see an increase into Sunday to 12 to 16 ft.
Southwesterly swell continues through the weekend.

Inside Waters: The next system has moved into the area bringing
southeasterly winds across the inner channels between a moderate
to fresh breeze (11 to 21 kt), and up to a strong breeze (22 to
27 kt) for northern Lynn, Frederick Sound, Stephens Passage, and
near the ocean entrances. The channels will see a brief increase
as the fronts move across the panhandle this weekend into early
next week. Northerly outflow will strengthen over northern Lynn
Sunday as the pressure gradient begins to tighten, bringing near
gales in the morning becoming gales into the day Sunday. Largely
expecting between 35 and 43 kt winds down Lynn Canal lasting from
Sunday into early next week, with the stronger northerlies moving
southward down to Point Couverden Sunday night into Monday. This
will allow some lower level convergence right around Point
Couverden from the southeasterly winds up Chatham Strait and the
northerly outflow coming down out of Lynn Canal, bringing winds
around Rocky Island to around 25 to 30 kt. Frederick Sound near
Cape Fanshaw and up along Stephens Passage will continue to see
strong breezes to near gales throughout the weekend, alongside
Clarence Strait seeing near gales as the fronts move through and
bring stronger southeasterly winds.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory until 9 PM AKST this evening for AKZ317.
Strong Wind from 9 PM AKST this evening through this evening for
AKZ317.
Strong Wind late tonight for AKZ317-318.
Winter Storm Warning until 3 PM AKST Sunday for AKZ318-319.
Winter Storm Watch from late tonight through Monday afternoon
for AKZ320>322-325.
MARINE...Gale Warning for PKZ012-036-053-651-652-671-672.
Small Craft Advisory for PKZ013-021-022-031>035-641>644-661>664.

&&

$$

SHORT TERM...GFS
LONG TERM...Bezenek
AVIATION...STJ
MARINE...GFS

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