Graphical Hydro Meteorological Discussion

904
FXAK68 PAFC 220117
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
417 PM AKST Fri Nov 21 2025

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

An area of low pressure currently over the western Sound and soon
to overspread Whittier continues to be the focus for winter
precipitation this afternoon and tonight. Current radar shows
light returns from the Knik Arm down through Cook Inlet,
Anchorage, and the Kenai Peninsula, with additional returns
pushing into Prince William Sound and the coast. Snow has been
persistent across Homer and Seldovia where a winter weather
advisory remains in effect for 4 to 10 inches of total snowfall
through Saturday morning. Snow has been much lighter elsewhere
from Kenai into Anchorage, and only a dusting to possibly one half
inch is forecast. Temperatures have warmed to above freezing
along portions of the Seward Highway from the eastern Turnagain
Arm down to Seward, and rain has been the primary form of
precipitation. However, temperatures are expected to drop below
freezing again later this evening/tonight with an additional 1 to
3 inches forecast from Girdwood to Turnagain Pass.

As the low continues to lift further inland light precipitation
will remain possible through early Saturday morning while also
expanding into the Susitna Valley. Model guidance has a second
smaller trough dropping south from interior Alaska, converging
upon the Southcentral low, with a brief chance for a second round
of snow spreading into western portions of the Susitna Valley
after midnight tonight. Accumulations here will also only amount
to a dusting.

Precipitation across Southcentral clears out over the weekend
with cooler temperatures to set in across the region. As soon as
precipitation comes to an end on Saturday morning the potential
for patchy fog will increase across the Mat-Valley, Anchorage
Bowl, and Western Kenai Peninsula. Expect highs on Saturday to
remain below freezing for all but coastal locations. Temperatures
will trend cooler into Sunday with morning lows in the teens for
the MatSu and Western Kenai Peninsula, to single digits across the
Copper River Basin.

-BL

&&


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

A compact low pressure system diving across the Alaska Peninsula
(AKPen) will promote gusty northwesterly winds out of favored gaps
and passes on the southern side of the AKPen this evening
diminishing tonight. As the low exits south, northwesterly winds
will be drawn down the eastern Bering along portions of the
Southwest Coastline. Simultaneously, a shortwave moving south over
the Kuskokwim Delta will bring a quick shot of snowfall to the
region tonight. Expect up to 2 inches of new snowfall from this
wave. These systems will work in tandem to create a period of
blowing snow across the Kuskokwim Delta. The worst conditions are
expected along the coast, from Kipnuk to Toksook Bay 9pm to
midnight tonight.

Temperatures will trend steadily cooler across the Bering Sea and
Southwest Alaska in the wake of this low, with low temperatures
dropping into the 20s for the Alaska Peninsula Saturday and Sunday
nights, with single digit lows for the interior Kuskokwim Delta
and Lower Kuskokwim Valley. Freezing fog over the greater Bristol
Bay region is possible Saturday morning. Out west, a North Pacific
low lifts to near the Western Aleutians by Saturday. Its front
brings strong winds, up to storm- force (50 kts) across the
western and central Aleutians along with moderate to heavy rain.
The low remains south of the Aleutians through the weekend, its
front lifting slowly into the eastern Aleutians through Sunday
night. Southwest Alaska remains dry and cold under offshore flow
on Sunday. Sunday night/Monday morning may see negative low
temperatures from the lower Kusko Valley into the Kuskokwim Delta.

-CL

&&


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

Starting on Tuesday, a vertically stacked low and large cyclonic
circulation will be centered south of the Aleutians in a weakening
phase. Short-waves embedded within the circulation will track from
east to west from the western Gulf/Kodiak Island across the Alaska
Peninsula and Bristol Bay and continuing westward across the
southern bering Sea. None of the features look particularly
strong, so would expect areas of precipitation and wind with
typical winter- time impacts. Precipitation-type will be mainly
rain, with Bristol Bay being the only location cold enough to see
snow. The upper low will open up into a trough by Thursday
(Thanksgiving), causing winds and precipitation to diminish.

Meanwhile, a strong ridge in the Arctic will build southward over
the northern half of mainland Alaska. This looks far enough south
to block any short-waves from the Aleutian trough from reaching
interior SW AK or Southcentral AK. Thus, expect seasonably cool
and dry conditions for these areas Tuesday through Wednesday. A
short-wave will dig down the east side of the ridge on Wednesday,
across the Yukon and into the Copper River Basin. This will bring
marginally colder temperatures, though accompanying cloud cover
will likely limit temperature drops. This trough will force the
upper ridge to retreat back northward and allow a short-wave
trough to approach Southcentral on Thursday. Model agreement with
this feature is not great, but ensembles generally support this
idea. With a cold air mass in place over Southcentral, the most
likely outcome would be widespread light snow arriving sometime
Thanksgiving Day.

As we continue to Friday, model guidance is in excellent agreement
on amplification of the upper level flow and development of an
Atmospheric River. However, as would be expected this far out in
time, there is large spread in the location of the ridge/trough
and track of a leading surface low from the Pacific. This evolving
pattern does have good potential to bring higher impact weather
to southern Alaska, with strong winds, mixed precipitation-types,
and warming temperatures. Stay tuned as we monitor the location of
key features and identify the areas where the greatest impacts
are most likely.

-SEB

&&

.AVIATION...

PANC...AN area of low pressure over western Prince William Sound
will continue to pinwheel moisture and cloud cover over Anchorage
and the terminal through early Saturday morning. MVFR ceilings are
expected to persist through late this afternoon then lower to low
MVFR or IFR ceilings and vis as steadier light snow develops.
Light snow should taper off by 12z, early Saturday morning, as the
low weakens and moves inland.

Lingering low-level moisture and a weakening wind flow in the
lower half of the atmosphere will likely result in low stratus
remaining over the terminal through Saturday morning. There is a
chance that this cloud deck either continues to lower through
early to mid morning, or erodes just enough to result the
development of fog due to additional radiational cooling. Either
way, clearing behind the low is not expected. Moreover, any drier
air aloft coupled with lingering low stratus and/or fog, could
result in some light flurries or freezing drizzle early to mid
Saturday morning. Right now, this is a low confidence solution,
but will be monitored.

&&


$$

794
FXAK69 PAFG 212243
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
143 PM AKST Fri Nov 21 2025

.SYNOPSIS...Snow has developed across the Central and Eastern
Interior and will persist through Saturday before tapering off
Sunday. Accumulations of 6+ inches are likely in the hills off
Chena Hot Springs Road and north and east of Eagle Summit.
Generally 3 to 6 inches from Fairbanks to Livengood and east to
Eagle Summit, though areas beneath convective snow bands may see
locally higher amounts. Light snow persists in the Brooks Range
and along the Arctic Coast east of Deadhorse through Sunday. Snow
showers and winds along western capes along the west coast
diminish Saturday. High pressure builds in Sunday, bringing drier
and colder conditions to Northern Alaska next week, as well as
increasing northeast winds and blowing snow with low visibility
north of Fairbanks.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Steadier snow arrives Friday afternoon/evening and continues
through Saturday night. Some showers remain early Sunday.
- 6 to 12 inches of heavy snow in the White Mountains and
elevated terrain south of the Yukon Flats. A Winter Storm
Warning has been issued for heavy snow. The heaviest snow will
be north and east of Eagle Summit, especially near Circle and
Chalkyitsik.
- 2 to 4 inches in Fairbanks area (including Eielson), though
areas beneath heavier bands of snow could see 6+" similar to
the White Mountains.
- 1 to 3 inches from Delta to Nenana north/west to Bettles.
- Little to no snow accumulations from Tok south/east.

- Colder and drier conditions return next week.

- Clouds clear late Sunday into Monday. Temperatures decrease in
valley locations under clear skies as stronger temperature
inversions develop.

- Increasing northeast winds Monday through next week. Areas of
blowing snow and low visibility with difficult travel conditions
over Dalton, Elliott, and Steese Highway Summits next week.

West Coast and Western Interior...
- Showery snow and gusty northwesterly winds slowly diminish
Saturday.
- Light snow for the Western Interior Friday and Saturday around
1 to 2 inches.
- North-northwesterly winds along the coast with gusts of 30 to
40 mph through Friday. Western Interior gusts 15 to 25 mph
Saturday.

- Colder and drier conditions return next week.

- Increasing east and northeast winds Monday through next week.

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

North Slope and Brooks Range..
- Light snow continues on the Slope, Beaufort Sea Coast and in the
Brooks Range this weekend. 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 through Sunday.

- Colder and drier conditions return 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...Broad troughing and low
pressure is present across the state with abundant moisture locked
into the area of low pressure over the Interior. Areas of snow
will continue to develop this afternoon as a vorticity maximum
drifts south over the area. This snow will continue through
Saturday before diminishing Sunday. Expect 2-4" in the Fairbanks
area and 6+ inches for the White Mountains. Due to the convective
nature of the snow event, areas beneath heavier bands may see 6+
inches of snow, even in the Fairbanks area. The official snow
forecast continues to be much higher than model guidance due to
the convective nature of the event, the fact that we are
anticipating snow to be low density and of the fluffy variety, and
the similarity of this setup to December 2024 when snowfall
overperformed model guidance over multiple days.

Across the west coast, northerly flow weakens Saturday as high
pressure shifts east to the Beaufort Sea. This will put an end to
the areas of blowing snow and snow showers through the Bering
Strait and across Western Capes. As high pressure builds over the
Beaufort Sea and continues to move east early next week, expect
skies to clear across the area and for the current warmer than
normal temperatures to become colder than normal. By Monday
afternoon, the entire forecast area looks dry and mostly clear.

&&

.EXTENDED FORECAST DAYS 4-7...We are monitoring 2 significant
pattern changes in the extended period. The first is high
probability and is an increase in northeast winds across the whole
area Tuesday through the end of the week. This is as high pressure
drifts east over the Yukon Territory while low pressure moves over
the Aleutians. This increase in wind will likely cause snow that
falls this weekend to blow and for visibility to be reduced,
especially over Dalton Highway summits and north of Fairbanks. The
second pattern change we are monitoring is toward an amplified and
potentially impactful pattern in the next Friday-Monday time
period. Models show remarkable agreement for warm air and moisture
from as far south as 20 degrees north being advected toward
mainland Alaska to the east of the North Pacific ridge. It is too
early to pin down exactly where and when warm air and
precipitation will reach, however there is potential for a heavy
precipitation event, likely a mix of rain and snow, in Northern
Alaska next weekend.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Warning for AKZ833-834.
Winter Weather Advisory for AKZ838-842.
PK...Small Craft Advisory for PKZ801-850.
Heavy Freezing Spray Warning for PKZ801-852-853.
Brisk Wind Advisory for PKZ802-803.
Heavy Freezing Spray Warning for PKZ804.
Small Craft Advisory for PKZ805-806-852>854.
Heavy Freezing Spray Warning for PKZ805.
Heavy Freezing Spray Warning for PKZ806-807-854-856>858.
Small Craft Advisory for PKZ807.
Brisk Wind Advisory for PKZ808>810-855.
Brisk Wind Advisory for PKZ811.
Small Craft Advisory for PKZ816-817.
Heavy Freezing Spray Warning for PKZ816-817-851.
Heavy Freezing Spray Warning for PKZ850.
Small Craft Advisory for PKZ851.
Gale Warning for PKZ856.
Small Craft Advisory for PKZ857.
Small Craft Advisory for PKZ858.
&&

$$

Chriest

495
FXAK67 PAJK 220007
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
307 PM AKST Fri Nov 21 2025

.SYNOPSIS...
Key Messages:

- Showers continue filtering through the panhandle, with isolated
thunderstorms possible into Friday night.

- Winter Weather Advisory for the Klondike Highway has been
cancelled early. Snow is still expected, but not at advisory
levels.

- Active shower pattern continues through the weekend with
potential for outflow to develop early next week, bringing
colder temperatures and drier weather

&&

.NEAR TERM.../Today and Tonight/...Forecast remains on track with
southwest onshore flow continuing to push showers into the
panhandle through the day Friday. Isolated thunderstorms are still
forming along the outer gulf coast through the afternoon, though
most lightning strikes have been concentrated in the Fairweather
range as convective potential begins to weaken. A weak shortwave
trough has rotated into the eastern gulf this afternoon and will
bring a bought of more organized rain to the panhandle Friday
evening. Only half an inch or less is forecast for the entire
panhandle, with northernmost areas expected to only see around a
quarter of an inch. Shower development is expected to ramp back up
behind the shortwave, with potential for isolated thunderstorms
directing into the central and southern panhandle.

The winter weather advisory for the White Pass area has been
cancelled a few hours early, as the bulk of the snowfall has
passed. Snow showers will still be moving through the area
overnight, with accumulations lessening into Saturday. Around 3
inches are expected at higher elevations, and periods of blowing
snow will be possible with gusty winds diminishing through the
night.

.SHORT TERM.../Saturday and Saturday Night/...Precipitation
continues its downward trend through the day on Saturday, with
showers becoming less numerous by Saturday night, with a respite
from the recent rounds of precipitation in sight for Sunday.

Aloft, the steering flow is finally shifting, with the rex block
over the interior of the state falling apart as the high pressure
to the north weakens, opening the way for the broad area of
troughing over the Gulf to be ejected eastward through Sunday and
Monday.

On Saturday, this will materialize in the lower levels as a
weakening low diving into the central Gulf. The low`s positioning
will ensure that the bulk of the shower activity stays offshore,
orbiting around the low, as onshore flow concurrently diminishes.
By Saturday night, PoPs will have dropped significantly across the
northern half of the panhandle as a result, although higher
chances of precip may linger for the far southern areas as a weak
shortwave sweeps in. Most areas near sea level will still see
precipitation fall as rain early on, though chances of snow mixing
in will rapidly increase in areas near sea level through the day.
Otherwise, snow is expected for mountain tops, with some
accumulation likely as well along the Klondike and Haines
Highways.

Temperatures will be on a general downward trend by Saturday
night as cold air advection from the western part of the state is
swept around the southern flank of the low and moves into the
panhandle. Winds will generally remain on the lower side, with 5
to 10 kt for many of the inner channels, and 15 to 20 kt for much
of the outer coastal waters. The main changes made to the forecast
were a downward trend in temperatures for some locations Saturday
night, along with an earlier changeover to mixed precip for some
locations, and lower wind speeds by lat Saturday in the inner
channels as the pressure gradient goes increasingly parallel.

.LONG TERM...For the start of the long term, current forecast guidance
looks similar to yesterday with a low persisting in the Northern
Gulf before weakening even further. Meanwhile, high pressure looks
to continue to build over the Interior and into the Yukon. With
this high pressure setting up, colder air will be able to slip to
the south. Current forecast guidance keeps most of this colder air
in the Yukon and away from the Coast Mountains. GEFS and EPS
guidance continues to still show some disagreement, especially
with the location of the high as it develops over the North Slope.
If the high can develop closer to the Yukon and British Columbia,
we could be looking at our first significant outflow event as
there is a potential for a low to move by to the south of the area
which could make for a tighter pressure gradient. This could
arrive just in time for the middle of the week allowing
potentially some of the coldest high temperatures we have seen
since last winter. But with the continued disagreement the
forecast is still trending towards a warmer solution. But this
will need to be watched through the weekend for any potential
changes. Otherwise, the extended forecast continues to be cooler
for next week before a potentially warmer and wet pattern returns
for the end of the month.

&&

.AVIATION...Widespread showers across the panhandle (especially
in the northern half) with embedded thunderstorms occurring along
the outer coast today (mainly from Baranof Island to Yakutat).
Some of those showers have been heavy with occasional drops in
visibility or ceilings to IFR. Convectively unstable conditions
are still dominate across the gulf and the overall SW flow pattern
has all of those showers that develop slamming into the outer
coast. Lightning detection has been lighting up all day along the
outer coast as the showers receive additional lift from hitting
the higher terrain with Sitka actually reporting lightning and
some small hail at times while Elfin Cove has seen some ice
pellets. These conditions are expected to continue through the day
and may last through late tonight as unstable atmospheric
conditions and SW flow persist across the panhandle and gulf.
Expect occasional lightning to continue along the outer coast
with the area of most frequent lightning likely extending down to
Prince of Wales Island this evening as a weak low moves inland.
The heavier showers may also have some ice pellets or small hail
and vis and ceilings may drop as low as IFR at times. Saturday
will feature less frequent and weaker showers as the instability
across the gulf becomes more stable and overall flow becoming more
southerly as the day goes on.

Gusty surface winds continue to be observed in the Lynn Canal,
Haines, and Skagway areas today and occasionally gusty winds are
also be observed near heavier showers. These wind conditions are
expected to continue and may be accompanied by some weak low level
speed shear (SE winds to 30 kt at 2000 ft agl) in the southern
panhandle this evening as a short wave moves into that area.
Expect gradually diminishing wind late tonight into Saturday.

&&

.MARINE...
Outside Waters: A broad swath of southwesterly fresh to strong
winds (17 to 27 kts) have persisted in the central gulf through
the day, and will steadily diminish overnight. 15 to 20 ft wave
heights with 15 ft of southwesterly swell at a 15 second period
will follow through the central gulf before quickly diminishing
below 15 ft into Saturday. 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 Saturday, alongside wave heights
decreasing to 8 to 12 ft by Saturday night.

Inside Waters: Showers continue moving through the panhandle with
southwesterly onshore flow directing winds up through the
channels. Fresh to strong southerly breezes (17 to 27 kts) in N/S
facing channels will be diminishing through Friday night, becoming
light to gentle breezes (4 to 10 kts) by Saturday night. Near
gale force gusts (28 to 33 kts) will persist overnight before
decreasing through Saturday, with potential for isolated gusts up
to low end gale force Friday night in Northern Lynn Canal and
Stephens Passage. 2 to 4 ft wave heights are expected for the
inner channels, with 10 to 15 ft wave heights for channel
entrances decreasing to below 10 ft by Saturday. There is a chance
for isolated thunderstorms to push into the southern channels
through Friday night.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-022-031-036-053-641>644-651-652-
661>664-671-672.

&&

$$

NEAR TERM...ZTK
SHORT TERM...GFS
LONG TERM...SF
AVIATION...EAL
MARINE...ZTK

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