Graphical Hydro Meteorological Discussion

816
FXAK68 PAFC 160310
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
610 PM AKST Mon Dec 15 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(Days 1 through 3: This afternoon through Thursday evening)...

Key Messages:

* Strong northerly winds were slow to come down today but have
begun to diminish this afternoon and tonight, though not end
completely for areas prone to channeled terrain/gap winds.

* Exceptionally cold temperatures return to the Copper River
Basin.

Discussion:

The surface high pressure over Interior Alaska and low in the
eastern Gulf has kept a tight pressure gradient over the region
for much of today. However, winds are starting to come down across
Southcentral this afternoon. Palmer, though, remains quite gusty
with wind gusts still near 65 mph. Even with the pressure
gradient easing some, once these winds through channeled terrain
start, they tend to keep going until the gradient really
diminishes. This looks unlikely to happen over the next few days
with the general pattern not changing much. Therefore, areas such
as Valdez/Thompson Pass and Seward and Whittier will likely still
see windy conditions for the next few days. The Matanuska Valley,
especially near Palmer, is in the same boat with northeast winds
continuing to accelerate through the exit of the Matanuska River
Valley gap for the next few days.

For areas that see the winds diminish completely, expect
temperatures to plunge by 20 to 30 degrees as skies will remain
generally clear. This is especially true for the Copper River
Basin for when winds drop, they could see ambient temperatures as
low as 40 to 50 below zero during nights and early mornings.
Therefore, a Cold Weather Advisory has been issued for the Copper
River Basin from tonight through Noon Thursday. Winds look to
return Thursday as a strong Arctic shortwave digs southward across
the Copper Basin, through Valdez/Thompson Pass, and into the
Gulf. The arrival of winds will help to warm temperatures across
the Copper River Basin. This strong shortwave will also help to
further enhance winds through Thompson Pass and into Valdez as
well.

&&


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

The almost perpetual ridge continues to be present in the Bering,
which is allowing for dry conditions across Southwest Alaska.
However, a compact shortwave is making its way through the
eastern Bering, bringing scattered snow/rain showers to the
Pribilof Islands and later, the eastern Aleutians and Alaska
Peninsula. Gusty winds are being seen in the aforementioned areas
due to cold air advection and the shortwave. Temperatures in the
Kuskokwim regions will be in the negatives and negative 10s
tonight due to a cold air mass moving in from the north. Bristol
Bay will see temperatures around zero.

Tuesday has the cold air mass sink further into Southwest Alaska.
This will enhance the gap winds in the eastern Aleutians and
especially the Alaska Peninsula. Winds in communities like Sand
Point, Chignik, and Perryville could see winds gusting to 60 to 75
mph. A High Wind Watch has been issued for these communities due
to this threat of gusty winds. Across the mainland, temperatures
will become even colder with negative temperatures likely for all
of the Kuskokwim Delta and even Bristol Bay. The Kuskokwim Delta
will see ambient temperatures in the negative 10s and negative 20s
in low and calm spots. Wind chills in the Kuskokwim areas will
make temperatures feel like the negative 30s.

Wednesday into Thursday has a shortwave sneaking through the
ridge, allowing for some warm air advection into the East Bering.
This will allow for the gap winds in the Eastern Aleutians and
Alaska Peninsula to decrease in speed, reaching a minimum by
Thursday. Another effect of the shortwave is a band of
precipitation making it all the way into the mainland by Thursday,
bringing snow showers to first the Pribilof Islands, then into
the coastal Southwest Mainland. Looking ahead, it appears that
the strong ridge is beginning to show signs of erosion with more
shortwaves chipping away at it into the weekend. This means that
more active weather could be on its way. Much uncertainty remains,
however, so monitor the forecast for updates.

-JAR

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

The highly amplified pattern continues through this weekend. High
pressure centered south of the Aleutian Islands along with low
pressure in the eastern Gulf of Alaska will keep gusty gap winds
persistent across the Alaska Peninsula and through the western
Gulf. Winds in general will be weaker than this past weekend and
early this week, with a messier pattern of weaker shortwave
troughs aloft. Temperatures remain below average across
Southcentral Alaska, with the coldest area being the Copper River
Basin, where ambient temperatures will hover in the range of 30
to 40 below zero. Southwest Alaska, however, will see warmer,
somewhat moist air ride up and over the ridge. A weak disturbance
moving through Southwest Alaska on Thursday exits into the Gulf
on Friday, leaving some lingering upslope snow showers, primarily
along the Kuskokwim Mountains and Western Alaska Range. The
passing wave could also lead to a brief increase in winds out of
gaps. Heading into the weekend, a series of low pressure systems
track up the coast of Far Eastern Russia toward Western Alaska.
This increases chances for precipitation in Southwest Alaska
Saturday night into Monday. Precipitation is likely to be mostly
snow, though rain is possible along the coast, and is increasingly
likely southward along the Alaska Peninsula. By Sunday, these lows
advect warmer air into the area, with temperatures rising into
the 20s and low 30s for much of mainland Southwest Alaska.
Southcentral Alaska looks to remain mostly dry and downsloped in
northwesterly flow, though some isolated snow showers cannot be
ruled out this weekend.

Quesada

&&
.AVIATION...

PANC...VFR will prevail through the TAF period. Strong
north/northeast winds will continue to weaken through this
evening but will remain around 10 to 15 kt out of the north
through tomorrow morning.

&&


$$

572
FXAK69 PAFG 152246
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
146 PM AKST Mon Dec 15 2025

.SYNOPSIS...
A very cold weather pattern continues across much of the region
with the coldest air remaining over the Eastern Interior where
temps are 25 to 35 degrees colder than normal. A pair of
disturbances over the next few days will bring some periods of
light snow to the North Slope and areas along the West Coast.
These systems will also push some cloud cover and light snow over
frigid portions of the Interior, potentially bringing some
limited relief from the extreme cold. Meanwhile a disturbance
dropping south from the Beaufort could bring blizzard conditions
to the eastern Arctic Coastline Tuesday into Wednesday.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...

- Clouds move in tonight and Tuesday with some light snow possible
from the Fairbanks metro westward. This will limit the very
cold temperatures to teens and 20s below zero.

- The rest of the week will see a mix of clouds and clearing.
However areas that see some breaks in the clouds will continue
to experience very cold temps. The far eastern interior will
also continue to feature much below temps for the next few days.

- North winds through Isabel Pass to 30 mph early this afternoon,
but should subside this evening. Winds will remain breezy into
mid week with areas of blowing snow and cold wind chills.

West Coast and Western Interior...

- Light snow will continue this afternoon into Tuesday as a
weakening disturbance tracks southeast from the Northern Seward
Peninsula. Snow accumulations will be light; generally 1 inch or
less, with NW winds 15-25 mph northwest of Kaltag.

- Another system has the potential to bring more significant
snowfall to most coastal areas and the Interior beginning
Wednesday night and lasting through Thursday, though
accumulations do not look to be greater than 4".

North Slope and Brooks Range...

- An area of snow will track across the North Slope through
Wednesday with light snow and west/northwest winds gusting 20 to
40 mph.
- Snow accumulations around 1 to 3 inches along the coast with 3
to 6 inches possible in the northern slopes of the Brooks
Range.
- Localized blizzard conditions possible, especially along the
eastern Arctic coast and in the Eastern Brooks Range by
midweek. A Blizzard Warning has been issued for Kaktovik from
Tuesday afternoon through Wednesday for potential wind gusts in
excess of 50 mph and visibility below 1/4 mile.

&&

.FORECAST ANALYSIS AND DISCUSSION...
Our current cold snap may have hit it`s peak this morning with
many locations experiencing their coldest temps in a couple of
years including Fairbanks where the temp briefly fell to -41F.
The good news is that temps should moderate a bit for a couple of
days as a disturbance is currently crossing the northwest coast of
Alaska and will manage to spread snow and clouds southwards from
the western North Slope and West Coast into parts of the Interior
through Tuesday. The highest snow totals will likely be confined
to the western Brooks Range, but much of northern and western
Alaska should see at least a few inches of new snow. Across the
Interior, confidence is high that we will see snow Tuesday as much
of the column will be saturated. But at these cold temps, total
available moisture remains limited. As such this system will not
manage to produce snowfall like the most recent system did.

Probably the most impactful weather the next couple of days will
be associated with a disturbance dropping south from the Beaufort
Sea towards the eastern Arctic Coastline. While this system will
spread snow along the North Slope from Utqiagvik to Barter Island
through Wednesday, it is the potential for strong winds that will
be most concerning. The gradient between the approaching surface
low to the north and the strong surface high over the Eastern
Interior will help generate strong easterly flow along the coast.
Guidance suggests winds of 35 to 40 mph gusting upwards of 50 mph
at times late Tuesday into Wednesday from Point Thomson to
Kaktovik. With the potential for blowing snow and visibilities
well below 1/4 mile, the decision has been made to upgrade the
current Winter Storm Watch to a Blizzard Warning for the eastern
Arctic Coast. Meanwhile a Winter Weather Advisory will be hoisted
for the coastline west of this area extending back to Prudhoe Bay
where winds will generally be a little less strong, but still
sufficient to generate a decent amount of blowing snow.

&&

.EXTENDED FORECAST DAYS 4-7...
Once again the extended period begins with a highly amplified
pattern consisting of a deep trough extending from the Yukon down
into the Gulf with a ridge extending from the North Pacific up
into Siberia. This also leads to a stark temp contrast with above
normal temps along the west coast with much below normal temps
across the east. As far as the future of this pattern, models are
still trying to slowly break down the ridge, but are still likely
a bit too quick and aggressive in doing so. Using ensemble means
as a basis for this forecast package, it seems like we will see a
replay of the current setup with a disturbance dropping southeast
out of the Chukchi and bringing precip (mainly light snow) south
and east across the region Thursday and Friday. Should the ridge
buckle a bit in response to this, additional energy over Siberia
could then shift eastwards towards the west coast over the
weekend. Should this come to pass, the west coast would be in for
more significant precipitation over the weekend, including a
chance for a wintry mix in spots. However this is a very low
confidence call at this time.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ804.
Blizzard Warning for AKZ805.
PK...Brisk Wind Advisory for PKZ801.
Brisk Wind Advisory for PKZ802-805-812-852.
Brisk Wind Advisory for PKZ803-808-809-855.
Brisk Wind Advisory for PKZ804.
Brisk Wind Advisory for PKZ806-807-857-858.
Brisk Wind Advisory for PKZ810-853.
Brisk Wind Advisory for PKZ811.
Brisk Wind Advisory for PKZ813.
Brisk Wind Advisory for PKZ814-859-860.
Gale Warning for PKZ815-861.
Small Craft Advisory for PKZ816.
Heavy Freezing Spray Warning for PKZ816-817.
Small Craft Advisory for PKZ817.
Brisk Wind Advisory for PKZ850.
Small Craft Advisory for PKZ851.
Heavy Freezing Spray Warning for PKZ851.
Gale Warning for PKZ854-856.
Heavy Freezing Spray Warning for PKZ854.
&&

$$

Laney

053
FXAK67 PAJK 160740
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1040 PM AKST Mon Dec 15 2025

.UPDATE...

&&

SYNOPSIS...

Key Messages:

- Multiple Winter Weather Advisories and Warnings are in effect
across the central Panhandle and the Icy Strait Corridor.

- Cold temperatures continue, with very cold wind chills near
White Pass.

- Gusty outflow winds continue down Lynn Canal, Stephens Passage,
and near Point Couverden, with occasional gusts in Downtown
Juneau.

- Snow and snow showers will continue through tonight. Precip
slowly diminishes from north to south tomorrow.

- Drier, colder, and sunnier weather is looking likely later
this week.

&&

.SHORT TERM...The particularly complicated weather forecast
continues here in SE AK. A vertically stacked low is spinning in
the eastern gulf. This low has been bringing moderate snow to the
northern half of the panhandle, snow and rain showers to the
southern half of the panhandle, and thundersnow to the coast.

For the snow in the northern half, a stalled frontal boundary near
the Icy Strait Corridor is keeping light to moderate snow in
place. This looks to remain through tonight so the Winter Storm
Warnings for Elfin Cove, Pelican, Hoonah, and Juneau have been
extended into Tuesday morning. Forecasted additional snowfall
amounts tonight are around 6 to 10 inches for Juneau, Hoonah,
Elfin Cove, and Pelican. Some isolated higher amounts are likely
for areas where the topography can cause enhanced snowfall. Based
on reports from storm spotters from Gustavus, the Winter Weather
Advisory will be allowed to play out and expire later today. That
being said, overnight snowfall for Gustavus could be around 2 to 4
inches.

For the southeastern portion of the low, showers have developed
and will last through tonight. The main areas of concern for these
showers are the northern half of Prince of Wales Island and
Southern Baranof Island, and extending far inland as Kake,
Petersburg, and Wrangell. These showers will keep the on/off snow
in place so the Advisories have been extended or they remain
unchanged from inherited forecast. Snow showers by nature can
cause wide differences in snow totals over short distances. So
while the current forecast is calling for snow totals through
tonight around 3 to 6 inches, some isolated amounts of greater or
less than that range are likely.

For the lightning and thundersnow along the coast, reports from
the public and detection from satellites indicate lightning near
Sitka. This lightning potential will stay in the Sitka area
through today while spreading southward to the western Prince of
Wales and the Metlakatla area overnight.

.LONG TERM...For the start of the long term, a low will continue to
remain over the southern portion of the Gulf of Alaska. This low
will linger before ejecting inland Thursday. While this low ejects
inland, outflow conditions are expected to persist for the Inner
Channels with at least gales continuing for places such as Lynn
Canal and Stephens Passage. Although some local areas could
potentially reach storm force winds again such as Point Couverden.
As the low ejects inland, the cold air will work its way south
towards the southern panhandle bringing temperatures down again.
With the dropping temperatures, precipitation is expected to
return to snow before drying out for the end of the week. Places
like Prince of Wales Island and Ketchikan could see up to 2 to 4
inches of snow. Farther north, temperatures will drop as well from
where they have been down to teen and single digits for daytime
highs. Wind chills though are expected to be well below zero with
the ongoing outflow winds especially for the Haines and Skagway
areas. For the central and southern panhandles, temperatures are
expected to drop to the teens and 20s with overnight lows dropping
into the teens and single digits. Areas that are sheltered from
the winds could potentially see colder temperatures such as the
Mendenhall Valley. Headed into the weekend and start of next week,
below normal cold temperatures are expected to continue although
nothing near all time record breaking cold. The next potential for
precipitation looks to be sometime next week when a low returns
to the northern gulf. But there is decent amount of ensemble
uncertainty this far out.

&&

.AVIATION.../Until 06Z Wednesday/...As far as CIGs & VISs are
concerned, primarily flight conditions in the MVFR range are
expected with dips down to within the IFR category under heavier
precipitation bands through the TAF period. Gusty northeasterly
outflow winds continue for the northern half of the panhandle
while winds will be generally on the lighter side for southern
areas. LLWS magnitudes of up to around 35 kt centered at around 2
kft are expected to continue for the first part of the forecast
period.

&&

.MARINE...
Inside water: The arctic boundary is continuing to make marine
forecasts in the inner channels difficult. That boundary is
currently around Sumner Strait over to north of Sitka. To the
north of that boundary strong outflow winds prevail with freezing
spray (some of it heavy in the far north), and periods of snow
reducing visibility to a few miles at times. These conditions are
expected to continue (except for the snow which should be ending
Tuesday) for the north through mid week and possibly into next
weekend at least. Chance of a slight weakening in the outflow
Tuesday afternoon and evening, but it will only reduce winds
around 10 to 15 kt at most before coming back just as strong as
previously seen Tuesday night. South of the boundary south winds
prevail especially tonight with winds up to 25 to 30 kt expected
in some areas before diminishing into Tuesday. Visibility is also
better as most of the precipitation is rain rather than snow. Main
concern for the south is how fast the arctic boundary moves south
over the next several days and switches the southerly winds to a
northerly and bringing colder weather. Expect southern Chatham and
Sumner to switch to the north around Tuesday time period while
the Clarence strait might wait until Wednesday or Thursday before
switching to the N.

Gulf Waters: Area of low pressure 150 miles W of Sitka is slowly
moving NE and weakening as it goes. Expect the low to diminish
away by Tuesday morning and the remnants will either move inland
near Cross Sound or linger just off Cross Sound. In either case
expect winds across the gulf to weaken late tonight into Tuesday.
The Yukon high is expected to strengthen into Wed, So outflow
winds across the NE gulf are expected to strengthen again to gale
force by Wednesday with freezing spray near outflow areas possible
again. Seas remain high tonight with around 20 ft combined seas
being reported (with a S swell to 15 ft. 13 sec period). Gradual
improving trend for seas over the next few days as the S swell
subsides to 10 ft Tuesday and then down to 5 ft by Wednesday.
Combined seas expected to subside to 8 ft by Wednesday except near
outflow areas that could see seas up to 15 ft in some areas due to
the strong winds there.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Cold Weather Advisory until 6 AM AKST Wednesday for AKZ318.
Strong Wind until 6 AM AKST Tuesday for AKZ318.
Winter Storm Warning until 9 AM AKST Tuesday for AKZ321-322-325.
Winter Weather Advisory until 6 AM AKST Tuesday for AKZ323-326.
Winter Weather Advisory until 9 AM AKST Tuesday for AKZ327.
Winter Weather Advisory until 3 AM AKST Tuesday for AKZ328.
Winter Storm Warning until 6 AM AKST Tuesday for AKZ331.
MARINE...Heavy Freezing Spray Warning for PKZ011-012.
Heavy Freezing Spray Warning for PKZ053.
Heavy Freezing Spray Warning for PKZ053.
Storm Warning for PKZ651.
Gale Warning for PKZ011>013-022-031-053-643-644-662>664-671.
Small Craft Advisory for PKZ021-032>036-641-642-652-661-672.

&&

$$

SHORT TERM...GJS
LONG TERM...SF
AVIATION...JLC
MARINE...EAL

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