Graphical Hydro Meteorological Discussion

147
FXAK68 PAFC 210131
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
431 PM AKST Thu Nov 20 2025

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

Mixed precipitation in the form of rain and freezing rain from
the morning hours has finally tapered off over inland portions of
Southcentral. Latest satellite imagery depicts a low centered over
the Barren Islands between Kodiak and the Kenai Peninsula. Strong
south and southeasterly flow ahead of the low has allowed
temperatures across Southcentral to warm to above freezing for all
but the Copper River Basin where current temperatures range from
the teens into the 20s. Scattered rain showers are ongoing over
the Kenai Peninsula and Gulf Coast, with Homer, Seward, Portage
and Cordova all experiencing at least light precipitation. This
rain will continue through tonight and into the morning hours
while the low skirts the Kenai Peninsula east coast.

Low pressure then tracks just south of the Kenai Peninsula
through tomorrow afternoon, eventually lifting northward and over
far western Prince William Sound. Models deviate on timing of the
low`s track and just how far east the low will move while lifting
into the Gulf coast. Of greater certainty is tonight`s wind
forecast for Kodiak Island. Strong winds and cold air advection on
the backside of the departing low will see westerly winds gusting
up to 50 knots or more through the bays and passes of Marmot Bay
and Chiniak Bay. Gusts through the city of Kodiak will likely
approach 60 mph during the overnight hours tonight before
diminishing through the morning hours on Friday.

Despite the uncertainty, mixed precipitation chances are likely
to return later tonight and on Friday for portions of Southcentral
as low pressure moves into the Sound. The first chance will be
during the morning hours with the low`s northward movement.
Temperatures at the surface will cool somewhat tonight, resulting
in another round of potential freezing rain from the MatSu into
the Anchorage Bowl, and especially for areas along the western
Kenai Peninsula and eastern Turnagain Arm, including Turnagain
Pass and even locations as far south as Homer. Whatever
precipitation does fall should be light, though cannot rule out
black ice developing on some surfaces. A second round of light
precipitation is possible tomorrow afternoon, as what remains of
the low shifts across Cook Inlet as a weak trough. The latter
precipitation chances would likely fall as mostly snow as cooler
temperatures filter in from the north and west. Again,
precipitation amounts should be fairly light, with any
accumulations only ranging from a dusting to perhaps an inch or
two. Highest snowfall accumulations will be from Turnagain Pass to
Portage. Valdez will also experience light snow with a couple of
inches forecast through tomorrow night.

By Saturday, low pressure exits the region, resulting in a break
from unsettled weather. Dry conditions and calmer winds are
forecast Saturday into Sunday.

BL


&&


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


Key Messages:

* Winter Weather Advisory in effect until 6PM AKST this evening
for the Northern Bristol Bay Coast and Inland Bristol Bay.

* Winter Weather Advisory in effect until 3PM AKST this afternoon
for the Kuskokwim Delta Coast/Nunivak Island and Interior
Kuskokwim Delta.

* Gusty northerly winds and snow showers continue for the mainland
Coast, Interior Kuskokwim Delta, the Central/Eastern Aleutians,
Pribilof Islands, and the Alaska Peninsula for Friday

Discussion:

An exceptionally strong low pressure system, in the 940s mb,
continues to move northeastward along the Alaska Peninsula (AKPEN)
this morning. Dillingham has contended with warmer air thus far
which has allowed for more rain to mix in with the snow. Therefore
snow totals across Dillingham will be lower than forecast. Togiak
and Manokotak continue to see snow this morning. The Winter
Weather Advisory continues through 6PM AKST this evening for the
Northern Bristol Bay Coast and Inland Bristol Bay with snow totals
ranging between 4 and 8 inches. The heaviest snow is still
forecast to fall across the Ahklun Mountains. In addition to the
snow threat across portions of Bristol Bay, a Winter Weather
Advisory also continues for the Kuskokwim Delta and Kuskokwim
Delta Coast/Nunivak Island through 3PM AKST this afternoon. 3 to 6
inches of storm total snow across those areas continues to be in
the forecast as the band of precipitation affecting portions of
Bristol Bay reaches northward in the Kuskokwim Delta and Kuskokwim
Delta Coast. The higher-end totals along the coast look to be
south of Kipnuk where the snow band has persisted longest.
Meanwhile, radar has filled in nicely around Bethel as flow aloft
is switching to northeast and away from the downsloping
southeasterly flow, allowing precipitation to make it over the
Kuskokwim Mountains.

Snow showers will linger across mainland Southwest through today
and will continue into Friday as a colder airmass moves in.
Blowing snow with reduced visibility is possible Friday along the
coast, but especially for Nunivak Island and Nelson Island. While
the cold airmass will arrive to the southern AKPEN along with snow
showers Friday, temperatures will only be marginal in the 30s, so
blowing snow should not be too much of a concern there.
Visibility could still be significantly reduced in heavier snow
showers that pass overhead though. The same goes for the Central
and Eastern Aleutians. The Pribilof Islands may be more at risk
for some blowing snow Friday as they will be more in the heart of
the cold airmass.

Snow showers embedded in the northerly flow will become more
confined to to the mountain ranges across mainland Southwest as
snow showers across the Central/Eastern Aleutians, Pribilofs, and
AKPEN taper off with a ridge building into the central Bering Sea.
The core of this ridge moves to the northeast Bering by Sunday
morning with mostly quiet and cold conditions expected across the
majority of the domain.

Behind the northeastward propagating ridge, a North Pacific low
lifts to near the Western Aleutians by Saturday. Its front brings
strong gusty winds, up to storm-force (50 kts) across the Western
Aleutians and the marine areas near the Western Aleutians Saturday
afternoon. These strong gusty southeasterly winds make it to
around Adak by Sunday morning, along with light to moderate rain.

&&


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

A high amplitude blocking pattern will be building during the
long term forecast period with a ridge of high pressure stretching
from the north slope of Alaska to the southeast Panhandle while
broad low pressure sits over the Aleutian Chain and Bering Sea. A
surface low spinning up under the upper level trough will most
likely have their storm track shunted north due to the blocking
ridge, bringing Kodiak Island and Southwest Alaska the majority of
weather impacts Tuesday and Wednesday. The eastern Kenai
Peninsula may receive modest precipitation as well, but the
majority of Southcentral see clearer skies with little to no
precipitation. A tight pressure gradient along the north Gulf
coast will more than likely result in gusty gap winds in the usual
spots, such as the Copper River Delta, Thompson Pass, and
Matanuska Valley. Expect colder than average temperatures for
interior locations and warmer than average temperatures for the
Alaska Peninsula and Lower Kuskokwim.


&&

.AVIATION...

PANC...VFR conditions are expected to persist through Friday
morning. A stray freezing sprinkle may make it over the terminal
this afternoon and evening; however, any precipitation will be on
the order of a trace at most. No ice accumulation is expected
through tonight. Winds will remain out of the north at 10 kt or
less. A wintry mix of precipitation is expected to return by mid-
morning Friday. Precipitation may start off as a mix of freezing
rain, sleet, and snow before changing to all snow by late morning
or early afternoon. Freezing rain accumulations are, again,
expected to be very light, with up to a glaze of accumulation.
Snow amounts are expected to be less than an inch. However, there
is some forecast model uncertainty as to how much precipitation
will move over across the Kenai Peninsula and over the terminal
tomorrow. Any steadier precipitation tomorrow morning may drop
ceilings and visibilities to MVFR at times.

&&


$$

400
FXAK69 PAFG 202227 AAA
AFDAFG

Northern Alaska Forecast Discussion...UPDATED
National Weather Service Fairbanks AK
127 PM AKST Thu Nov 20 2025

Updated spelling mistake in extended

.SYNOPSIS...
The weather is quieting down on the West Coast with weakening
winds and snow showers diminishing in coverage. Snow will be
moving into the Central and Eastern Interior as early as today,
but the bulk of the steadiest snow arrives tomorrow
afternoon/evening and continues through Sunday. The North Slope, Beaufort
Sea Coast and Brooks Range will also see light snow develop
tomorrow and continue through Sunday. Colder and drier weather
arrives next week for most places in Northern Alaska.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- A few flurries or light snow showers today, steady snow arrives
Friday afternoon/evening and continues through Sunday.
- Snow accumulations will be heavy, 6 to 12 inches, in the White
Mountains and portions of the Eastern Interior, specifically
north and west of Eagle.
- 2 to 4 inches in Fairbanks area (including Eielson).
- 1 to 3 inches from Delta to Nenana north/west to Bettles.
- Little to no snow accumulations from Tok south/east.

- Dry and colder weather settles in next week.

- Decreasing clouds Sunday afternoon into the overnight,
temperatures drop across the board to the single digits for
highs and below zero for lows.

West Coast and Western Interior...
- Snow showers and wind gusts diminishing with drying conditions
becoming more prevalent along the coast. Light snow for the
Western Interior Friday and Saturday with accumulations around
an inch or 2.

- Drier and colder weather next week.

- Temperatures in the 20s to near 30 along the coast, then
decreasing through the weekend with highs in the single digits
and teens, and lows near or below 0 for many next week.

North Slope and Brooks Range..
- Light snow develops on the Slope, Beaufort Sea Coast and in the
Brooks Range tomorrow. Snow accumulations will be around 1 to 3
inches with a couple of spots near 4 inches in the Eastern
Brooks Range and near Kaktovik.

- Drier and colder weather returns next week.

- Widespread temperatures in the single digits with lows near or
below 0 along the coast, and potentially in the teens to 20s
below zero in the Brooks Range next week.

&&

.FORECAST ANALYSIS AND DISCUSSION...

An upper low near the AK Peninsula this morning is moving towards
South-Central this afternoon at about 501 decameters. This will
send a strong front northward into the Interior later today and
into Friday. The front will run into a 519 decameter ridge over
the Beaufort Sea on Friday causing it to stall and undergo weak
cyclogenesis near northern Yukon Territory. As a weak upper low
gradually develops, it will wrap moisture from the Bering Sea lows
to the Interior. The upper level energy, mid level moisture and
cold temperatures will combine to produce widespread light to
moderate snow this weekend across most of the Interior and North
Slope. One slight change to this is, a a ridge in the Bering will
be moving in, this has been strengthening on nearly every model
run since yesterday. A stronger ridge moving in, could potentially
provide more dry air to the Interior. This could be a reason for
lower snowfall totals from the snow event this weekend.

Nonetheless, widespread light to moderate snow from Friday
through the weekend may accumulate pretty substantially in some
spots. The highest snowfall totals will reside north and east of
Fairbanks, specifically the White Mountains, Steese Highway
Summits and out towards the AlCan Border north of Eagle. In and
around Fairbanks, expect around 2 to 4 inches. There is still a
possibility for more, as the heaviest snow begins about 30 miles
northeast of Fairbanks. South and west of Fairbanks, expect about
1 to 3 inches with totals diminishing the farther from Fairbanks
you are.

A couple of aspects that may change these snowfall totals are dry
air, heavier convective banding, and/or a farther southwest
progression of the upper low in Canada. All of these factors can
either diminish snowfall or increase it locally. However, given
the trends, we don`t anticipate a farther southwest progression,
but there may be more dry air (meaning less snow, especially from
Fairbanks west). Finally, with strong vorticity at 700 and 500mb,
convective banding is likely. It is almost impossible to say where
these bands will set up, but where they set up will most likely
see heavier snow than their surroundings.

&&

.EXTENDED FORECAST DAYS 4-7...
A ridge of high pressure continues to build over the Bering Sea
before making its way into the Chukchi Sea and eventually over
the Arctic by next Tuesday. This pattern will usher in colder and
drier weather across the state, which for the time being, looks to
persist well into next week. Simultaneously, a low will make its
way over the Aleutian Islands and move eastward into the Gulf of
Alaska. Depending on how the low moves and situates itself, this
could allow for a strong pressure gradient to set up across the
Interior, increasing the potential for some gusty winds within the
Tanana Valley. However, given model disagreement that far out,
confidence remains low. Overall, mostly quiet weather is expected
next week.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Watch for AKZ833>835-838-842.
PK...Brisk Wind Advisory for PKZ801-802.
Brisk Wind Advisory for PKZ803-809.
Heavy Freezing Spray Warning for PKZ804.
Small Craft Advisory for PKZ805-850.
Heavy Freezing Spray Warning for PKZ805.
Heavy Freezing Spray Warning for PKZ806.
Gale Warning for PKZ806.
Heavy Freezing Spray Warning for PKZ807-816-817-851-854-858.
Gale Warning for PKZ807.
Brisk Wind Advisory for PKZ808-855.
Brisk Wind Advisory for PKZ810-811.
Heavy Freezing Spray Warning for PKZ812.
Brisk Wind Advisory for PKZ813>815-859-861.
Small Craft Advisory for PKZ816.
Gale Warning for PKZ817.
Gale Warning for PKZ851.
Heavy Freezing Spray Warning for PKZ852.
Small Craft Advisory for PKZ852.
Small Craft Advisory for PKZ853-857.
Heavy Freezing Spray Warning for PKZ853.
Gale Warning for PKZ854.
Gale Warning for PKZ856.
Heavy Freezing Spray Warning for PKZ856.
Heavy Freezing Spray Warning for PKZ857.
Brisk Wind Advisory for PKZ860.
&&

$$

Bianco
Extended - Santiago

624
FXAK67 PAJK 210544
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
844 PM AKST Thu Nov 20 2025

.UPDATE...Aviation and near term update...
Forecast remains on track with abundant showers continuing as
front pushes out of southern panhandle and another front extending
from a gale-force low in the northwest gulf works into the
northern panhandle. Abundant lightning has been observed from
near Yakutat along the coast to down near Cross Sound and Icy
Strait. Thunderstorms remain in the forecast along the gulf
through Friday morning.

Snow continues overnight for the Klondike highway and the winter
weather advisory was extended until 9pm Friday.

&&

.SYNOPSIS...
Key Messages:

- Scattered showers and isolated thunderstorms over the N Gulf
developing in the wake of the front through Thursday night,
with showers across the panhandle lasting into this weekend.

- Winter Weather Advisory has been extended for the Klondike
Highway near White Pass until 9 PM Friday for long duration
snowfall, with an additional 8 to 10 inches expected through
Friday night.

.NEAR TERM.../Today and Tonight/...
Overall message remains consistent with the mid morning update.
As of this afternoon, the front has pushed about halfway through
the panhandle and continues to slowly meander northeast, with
onshore flow allowing for scattered shower development to be
directed into the northern outer coast. Light to moderate rain
rates and strong, gusty winds between 20 to 30 kts will continue
to move through, with isolated areas of heavy rain and gusts up to
45 kts. Overnight, only around half an inch of rain is expected
for a majority of the panhandle, with higher elevated areas seeing
up to an inch. Around 4.8 inches of snow is forecast for high
elevations of the Klondike Highway overnight, continuing into
Friday. The winter weather advisory has been extended until 9 PM
Friday night, for 8 to 10 inches total. The strongest winds are
forecast to generally decrease through the evening, though with
the pressure gradient turning more N/S oriented, areas of the
inner channels will persist at a fresh to strong breeze (17 to 27
kts) into Friday. Northern Lynn Canal will stay especially
elevated overnight around 35 mph with gusts up to 45 mph, keeping
Haines and Skagway elevated as well.

.SHORT TERM.../Friday and Friday night/...
Onshore flow is expected to continue into tomorrow morning as
shortwaves move across the panhandle from the systems lingering in
the Gulf, with more showery precipitation expected to last
throughout the day and into Saturday morning across the panhandle.
The heavier of the showers tomorrow morning into the early
afternoon will be largely across the northern half of the
panhandle, before the next wave moves in tomorrow night bringing
increased PoPs and QPF back to the southern half of the panhandle.
Overall expecting between 0.25 and 0.5 inches of precipitation
for the northern and southern panhandle throughout the day Friday,
and between 0.5 and 0.75 inches of precipitation in 24 hours for
the central panhandle as these areas will see more lasting showers
throughout the day during both waves of precipitation moving
through.

Snowfall amounts for the Klondike Highway between MP 10 and White
Pass will be between 4 and 6 inches in 24 hours Friday, with the
highest rates of snowfall being for the morning and into the
afternoon, before precipitation rates decrease into the evening.
The higher snow levels and warmer higher level 850 mb temperatures
Friday morning will keep this snow more wet and heavy, but
throughout the day snow levels and temperatures alike will
decrease, allowing for some higher snow ratios and less wet snow
later Friday evening. Winds from Skagway up to White Pass will be
increased throughout the day before diminishing into the evening
hours, with the highest being expected midday. Overall sustained
winds inland between 20 and 30 mph with gusts up to 35 mph at sea
level near Skagway in the late morning to afternoon. Winds across
the panhandle diminish Friday night into Saturday morning even as
showers linger across the panhandle.

.LONG TERM.../Saturday through Tuesday/...
For the start of the long term period, onshore flow will continue
to bring moisture onshore along with cold air aloft which will
allow for convective showers to continue Saturday into Sunday. If
some of the showers bring heavier periods of precipitation, there
is a chance that some areas for the central panhandle could see
minor snow accumulations. Headed into Sunday, forecast guidance
continues to show disagreements in the ensembles. If high pressure
takes more control of the Interior down into the Yukon and
British Columbia, there is a greater chance for cold and dry
conditions to become more widespread for the panhandle. With that,
outflow conditions would be more likely and winds through the
Inner Channels will be stronger than what is currently forecasted.
But if the high pressure is farther to the east and weaker,
onshore flow will likely continue to allow for showers to move
inland. While temperatures would likely be cool, they would be
warmer than the stronger high pressure solution. Current thinking
is that the high pressure will take control of the weather for SE
AK and we will start to see a cool down and drying, at least
through the weekend into the start of next week. But this will
need to be monitored for any potential changes. Headed into the
middle of next week, ensemble guidance shows a low over the
Aleutians along with a weakening front that could bring our next
impacts to the area. If the cold air is established through the
Inner Channels, this could potentially bring snow to parts of the
Panhandle outside of the Northern Inner Channels.

.AVIATION.../through Friday evening/...
General low-end VFR to MVFR flight conditions across the
panhandle as another front and onshore flow keep abundant showers
through the period. Brief IFR VIS and CIGs possible in heavier
showers. Lightning has been observed this evening along the gulf
coast from near PAYA to Cross Sound and Icy Strait. Did include
PROB30 TSRA for PASI through Friday morning. Lightning could also
occur across the rest of the region, mainly along the gulf, but
confidence is not high enough to include in the forecast.

Winds becoming 10-20G22-30kts across the north and for PASI.
Stronger winds for PAGY 20-30G30-40kts. Winds across the southern
panhandle will be lighter, generally less than 10kts. LLWS,
albeit much less stout than previous TAF issuances, could still
persist with winds 2kft aloft 25-30kts.

.MARINE...
Outside Waters: A broad swath of southwesterly gale force winds
blowing through the central gulf will steadily diminish through
Thursday night. 20 to 25 ft wave heights with 20 ft of
southwesterly swell at a period of 15 seconds will follow through
the central gulf before quickly diminishing below 20 ft into
Friday morning. Onshore flow continues to direct showers into the
panhandle with the occasional lightning strike along the outer
coastal mountains. The diminishing trend in the winds continues
through Friday, alongside wave heights decreasing to 12 to 15 ft
by Friday night.

Inside Waters: Largely southerly fresh to strong breezes (17 to
25 kt) across the inner channels following behind the frontal
passage this afternoon, decreasing to a moderate breeze (11 to 15
kt) over the central and southern inner channels tonight. The
continued weak shortwaves moving through into early Friday morning
and midday Friday will increase winds again to a fresh to strong
breeze, before diminishing again Friday night into the weekend as
the pressure gradients weaken across the panhandle. Northern Lynn
Canal and Stephens Passage will see lasting strong breezes to near
gales (22 to 30 kt) tonight through tomorrow evening before
diminishing as well. There will be a brief period midday Friday
where northern Lynn Canal will see Gale force southerly winds as
the N-S pressure gradient increases over the northern panhandle,
before easing up throughout the late afternoon into the evening.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory until 9 PM AKST Friday for AKZ318.
Strong Wind until 9 PM AKST this evening for AKZ318.
MARINE...Gale Warning for PKZ012.
Small Craft Advisory for PKZ011-013-022-031-036-053-641>644-651-
652-661>664-671-672.

&&

$$

UPDATE...DS
NEAR TERM...ZTK
SHORT TERM...Contino
LONG TERM...SF
AVIATION...DS
MARINE...Contino/ZTK

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