Graphical Hydro Meteorological Discussion

990
FXAK68 PAFC 201427
AFDAFC

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

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

Two fronts are merging in Prince William Sound this morning as a
deep low currently in southern Shelikof Strait tracks northeast.
Both of the fronts are bringing plentiful moisture and warm air
into the coastal mountains, and aloft temperatures are warming
quickly over the Cook Inlet regions and southern Mat-Su. Radar
returns indicate spill over precipitation and area ASOS stations
are reporting freezing rain in Anchorage and a mix of rain and
snow for the western Kenai. Winter weather advisories for freezing
rain are out until noon for these areas. Otherwise, areas that
have gotten the wind like the Mat Valley and mountainous areas of
the Kenai Peninsula are 34 to 40 degrees. Northerly winds will
continue to increase today which will gradually warm temperatures
into the mid 30s for the hold outs of Anchorage and the western
Kenai. Rain should come to an end late this morning for lee-side
areas after the upper level wave moves through.

Later this afternoon the low will be over the Barren Islands
before tracking either into the western Sound or up Cook Inlet
throughout the day Friday. Overall model consensus is now keeping
the low to the east of the Kenai Peninsula. Precipitation will
accompany the low, with colder air and rain transitioning to snow
to the west and south of the low center as it moves north. While
there is colder air moving in aloft, temperatures at the surface
are likely to be between 30 and 35 degrees due to the southerly
surface wind behind the low. Precipitation type is likely to be
snow but accumulation may be difficult due to warmer temperatures.
By Saturday temperatures will quickly cool down again and
precipitation will end as another low develops in the Gulf and
slowly occludes through the weekend.


&&


.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: Sunday through Wednesday)...

An omega block pattern will be in place at the start of the long
term forecast period with a dying low in the Gulf of Alaska,
building high pressure over the Bering Sea, and another low just
south of the western Aleutians. The tight pressure gradient
between the Bering high and Aleutian low will create a corridor of
southerly winds up to storm-force through the western and central
Aleutians Saturday night and Sunday. The low will track into the
Gulf of Alaska for the first half of the week, setting up a rex
block pattern with high pressure over the northern half of
mainland Alaska and low pressure over the southern Alaska and the
Gulf. Surface lows spinning up will likely bring elevated winds
and precipitation to the Bristol Bay region, Kodiak Island, and
the north Gulf coast Tuesday and Wednesday while the Copper River
Basin and interior Alaska stays cold and dry.


&&


.AVIATION...

PANC...While the terminal will remain mostly dry this morning,
light freezing rain is expected between 15Z and 18Z as a front
moves overhead with ample upper level support. Brief MVFR
conditions are possible during this time. After frontal passage
conditions will remain VFR with light northerly winds. The main
storm system currently southwest of Kodiak Island will track into
the Sound Friday morning, which may return light snow to the
terminal and southerly wind. MVFR to IFR conditions are expected.


&&


$$

588
FXAK69 PAFG 201338
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
438 AM AKST Thu Nov 20 2025

.SYNOPSIS... Snow continues on the West Coast as a low moves from
south to north over St. Lawrence Island through this afternoon.
Isolated areas of heavy snow are possible, especially in St.
Lawrence Island and southern Seward Peninsula through tomorrow
morning. Lighter snow and snow showers will reside in the Yukon
Delta through Saturday. The Interior will see light to moderate snow
begin to develop Friday afternoon and continue into Sunday,
especially for the eastern Interior and Yukon Flats. On the North
Slope, light snow will develop as well from east to west tomorrow
and continue through the weekend. Beginning next week, we are going
to begin to see a transition towards a colder and drier pattern.

&&

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

- Mostly sunny and dry today, clouds increasing tomorrow with
snow showers developing along the AlCan Border north of Eagle.

- Light to moderate snow develops across most of the Interior by
Friday night and continues through Sunday. Several inches of
snow possible from Tanana to the AlCan Border. There could also
be some locations along the Alcan Border and within the White
Mtns which may receive 6" or more through Saturday.

- High temperatures in the teens and low 20s with lows near or
below zero through the weekend. Temperatures will continue to
drop off past this weekend, with some areas dropping into the
-10s and -20s by early next week.

West Coast and Western Interior...

- Snow continues for the Bering Strait Region through today.
Heaviest snow will be in St. Lawrence Island and Diomede with
additional accumulations up to 6 inches in Gambell and Savoonga.

- Wind gusts along the West Coast increase today through
tomorrow, gusting 30 to 40 mph in most spots and up to 50 mph in
the Bering Strait and St. Lawrence Island.

- Some light snow showers will linger through the weekend,
especially in SW AK and the Western Interior. A few inches of
snow is possible.

- High temperatures in the 20s and low 30s with lows in the teens
and 20s through the weekend, coldest in the Interior.

North Slope and Brooks Range..

- Partly clear skies tomorrow, will become cloudier with
increasing clouds going into the weekend. More clearing will
occur next week.

- Stronger winds across the northeastern Arctic Coast will
gradually come down throughout the day.

- Light snow develops from east to west tomorrow, with steady
light snow from the Brooks Range northward through the weekend.
A few inches of snow are possible.

- High temperatures will be in the teens and 20s with lows in the
single digits through the weekend, then temperatures will begin
to drop off and become much colder throughout the following
week.

&&

.FORECAST ANALYSIS AND DISCUSSION...
An elongated upper level trough is parked over the Bering Strait,
with two associated areas of low pressure located over the Chukchi
Sea, and the second is south of St. Lawrence Island. Both of these
features are allowing for unsettled weather to continue today across
the Y-K Delta and Norton Sound. Strongest winds associated with the
low over the Bering Strait will be along the northern shores of St
Lawrence, from Gambell to Savoonga, where winds will be sustained
between 30 to 40 mph, and gusts may occasionally approach 60 mph. As
these lows continue to weaken and eject up to the northeast while
becoming absorbed into the ridge over the Arctic Ocean, it is going
to allow for conditions to improve going into tomorrow. There may
still be a few lingering snow showers going into the early part of
the weekend along the Southwest Coast, while most other areas will
become drier.

Meanwhile, there is another major shortwave trough with an
associated 950mb low at the surface, that is propagating across the
Aleutians this morning and will be entering into the Gulf of Alaska,
and will undergo weak cyclogenesis (intensification) as it does.
This will allow for a tightening of the gradient and force some gap
flow winds through the passes with some indication of a possible
mountain wave set up. This may allow for gusty winds through Isabel
Pass to approach criteria, however the period looks to be rather
brief, and only areas south of Air Force Tower appear to be the most
likely to reach criteria. This will continued to be monitored with
newer model runs later to determine if a product for this area will
be necessary. Regardless, expect rather gusty winds, with gusts
generally up around 30 to 40 mph. This will also help to produce a
low-level jet up through the Tanana Valley, which will also allow
for stronger winds to be possible for places such as Delta Junction.
Moisture will also be advected up from the south and help to
increase snow chances across the eastern Interior/Brooks Range and
Yukon Flats tomorrow through early Saturday. A separate area of low
pressure becoming stalled out right along the AlCan border is also
going to increase snowfall totals around Eagle, and there could be
as much as 6 inches (or possibly more) in the vicinity of this area
through the weekend, otherwise generally more on the order of 1-3"
can be expected across the eastern Interior and Yukon Flats, with
higher amounts expected within the White Mountains.

&&

.EXTENDED FORECAST DAYS 4-7...
By the later half of the weekend, there will still be some show
showers being possible over the eastern portion of the Mainland
going into Sunday, however, there will begin a much drier and colder
pattern beginning to establish itself as a strong ridge begins to
build in over the Bering Sea and then begin to slowly expand across
the northwestern portion of the state as the ridge further
strengthens over the Chukchi Sea, this will allow for most of the
state to become dominated by drier and colder conditions. Ensembles
reveal that there could be some areas across the North Slope and
within the Brooks Range dropping down into the -30s by the middle of
next week as northeasterly flow and clearing conditions continue to
support the drop in temperatures.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Warning for AKZ820-821-823-827.
PK...Brisk Wind Advisory for PKZ801.
Brisk Wind Advisory for PKZ802.
Small Craft Advisory for PKZ804.
Heavy Freezing Spray Warning for PKZ804.
Small Craft Advisory for PKZ805-850-853-857.
Heavy Freezing Spray Warning for PKZ806.
Gale Warning for PKZ806-807.
Heavy Freezing Spray Warning for PKZ807-812-816-817-851-854-856-
858.
Brisk Wind Advisory for PKZ808-810-855.
Brisk Wind Advisory for PKZ809-811.
Small Craft Advisory for PKZ812.
Brisk Wind Advisory for PKZ813-859.
Brisk Wind Advisory for PKZ814.
Brisk Wind Advisory for PKZ815.
Gale Warning for PKZ816-817.
Gale Warning for PKZ851.
Heavy Freezing Spray Warning for PKZ852.
Gale Warning for PKZ854.
Gale Warning for PKZ856.
Heavy Freezing Spray Warning for PKZ857.
Small Craft Advisory for PKZ858.
Brisk Wind Advisory for PKZ860-861.
&&

$$

Stewey

159
FXAK67 PAJK 201456
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
556 AM AKST Thu Nov 20 2025

.SYNOPSIS...

Key Messages:

- Gale force front pushes through the panhandle early Thursday.

- Winter Weather Advisory has been extended for the Klondike
Highway near White Pass until 6 AM Friday for long duration
snowfall, with an additional 6 to 12 inches expected through
early Friday morning.

&&

.SHORT TERM.../ Through Thursday night / Next frontal band
spreading out of the Gulf of Alaska into the panhandle on
Thursday. The northern panhandle has the remains of a previous
system lifting into Northwest Canada, will open the southern flow
pattern. The flow aloft of the panhandle keeps the snow falling
along the Klondike through the day with moderate accumulations.
Winds picking back up over the with front spreading into the
panhandle so expect to see the gusty winds of 35 to 45 mph at
times while the front pushes through the coastal communities and
along the inner channels. Winds becoming westerly by evening
hours behind the front so minor burst with the directions shift,
but the westerly flow will continue so should see showers/rain
continue with the onshore flow pattern.

.LONG TERM.../Friday through Monday/...Waves continue to rotate
around the low in the northwestern Gulf through the end of this
week, allowing for precipitation to continue across the panhandle
Friday into the weekend. There will be a general downward trend
in precipitation amounts as the low in the Gulf weakens Friday and
Saturday, before ridging begins to build Sunday into Monday,
bringing a drier and colder trend for early next week.

A shortwave will follow up behind the last wave of precipitation on
Friday, the highest rates being for the late morning through the
evening across the panhandle. Largely expecting between 0.4 and 0.6
inches in 24 hours across the panhandle Friday, with between 2 and 3
inches of snow in 24 hours for the Klondike Highway above 2000 ft
and less than an inch of snow expected for the Haines Highway near
the border. The snow being expected mostly in the night and early
morning for the Haines Highway and above 2000 ft for the Klondike is
due to the higher snow levels and warmer 850 mb temperatures Friday.

Both snow levels and 850 mb temperatures however will begin to
decrease over the northern panhandle into Saturday from the weaker
onshore flow and less warm air advecting into the area as the low
begins to weaken, and as a high begins to develop to the northeast /
east over British Columbia into Sunday. Precipitation will linger
across the panhandle but largely diminish Saturday into Sunday, with
the highest PoPs remaining along the outside coastline and southern
panhandle by Sunday. The northern panhandle will begin to rapidly
diminish Sunday night into Monday, as weak offshore flow from the N
and E from the surface high pressure strengthening over Canada while
the low diminishes to rather weak troughing over the Gulf. Snow
levels as well as temperatures will begin to drop into Monday,
particularly for the northern panhandle as 850 mb temperatures
decrease to -7 to -9 degrees C, however the lack of QPF will result
in a cold and drier pattern come for early next week. However, as
snow levels begin to drop and temperatures along with it Saturday
night and through Sunday, there is potential for some rain snow
mixing north of Icy Strait Corridor Saturday night through Sunday.
PoPs will decrease throughout this time frame and becoming a slight
chance to chance Sunday night, and the decreased QPF amounts will
lead to very little to no accumulation even if snow mixing occurs.
Even along the highways, the low QPF amounts Saturday and Sunday
will only allow for around an inch of snow accumulation.

&&

.AVIATION...Flying conditions this morning remain around MVFR to
VFR with broken to overcast ceilings between 2500 ft to 5000 ft.
These varying conditions are in place as the panhandle is
currently in the transition period between two systems. The first
system remains over the panhandle continuing to bring rain across
the area as the second system approaches. This first system is
keeping winds elevated for multiple areas this morning with
sustained winds of 15 to 25 mph. Specifically, Haines has had
frequent gusts to 40 mph this morning. Winds will remain elevated
but have a chance of very slightly decreasing before the next
system arrives. Along with these strong winds, wind shear
continues with SE winds of 35 to 40 kts around 2000 ft.

As the next front approaches this morning, moderate to heavy rain
returns along with increased winds. This will keep ceilings below
3000 ft, for most areas, and reduce visibilities below 4 SM at
times. Winds across the panhandle remain elevated around 10 to 15
mph for the southern panhandle and 15 to 25 mph for the northern
panhandle. The strongest of these winds will be near Skagway
Thursday evening.

&&

.MARINE...
Outside Waters:
A gale force front is pushing into the panhandle through early
Thursday. Coastal buoys currently reporting southeasterly
sustained near gales to gale force winds (28 to 40 kts) with gale
to storm force gusts (34 to 47 kts) decreasing through the next
few hours. Wave heights up to 22 ft with 20 ft southeasterly swell
will decrease to 10 to 15 ft overnight with 8 to 10 ft swell.
Another strong front will follow close behind, moving into the
gulf overnight and swinging up into the panhandle Thursday
morning. Southwesterly gale force winds will follow this front
through the central gulf, but strongest speeds will only reach the
coast through the early morning hours before pulling back to stay
in the central gulf. Speeds will gradually diminish to strong
breezes to near gales (22 to 33 kts) through Thursday. Wave
heights will increase back up to 25 ft offshore Thursday afternoon
with 15 to 20 ft swell turning southwesterly, but will quickly
decrease to around 15 ft into Friday morning.

Inside Waters:
Fresh to strong breezes (17 to 27 kts) continuously increasing
overnight. Lynn Canal will continue blowing 15 kts or less
overnight before the next surge flips it southerly. Another strong
front moves through the panhandle through Thursday morning,
widespread near gale to gale force winds (28 to 40 kts) will push
north through the channels. Speeds will begin to decrease through
Thursday afternoon, but will still stay elevated at fresh breezes
with spots of strong breezes before decreasing into Friday.
Channel entrances will see wave heights reach 10 to 15 ft with
both systems, dropping down closer to 10 ft in between. The rest
of the inner channels will see around 3 to 5 ft heights increase
to 6 to 8 ft with the peak of the front.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory until 6 AM AKST Friday for AKZ318.
Strong Wind this evening for AKZ318.
MARINE...Gale Warning for PKZ013-021-031>036-641>644-651-652-661>664-671-
672.
Small Craft Advisory for PKZ011-012-022-053.

&&

$$

SHORT TERM...Bezenek
LONG TERM...Contino
AVIATION...EAB
MARINE...Bezenek

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