Graphical Hydro Meteorological Discussion

309
FXAK68 PAFC 091328
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
428 AM AKST Sun Nov 9 2025

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

An upper-level trough continues to slide east toward Yakutat this
morning as a ridge of high pressure builds across Southcentral.
Lingering low-level moisture trapped underneath the building
ridge, coupled with weak winds in the boundary layer, have
resulted in widespread fog and low stratus across the Copper River
Basin west to the Kenai Peninsula, Anchorage Bowl, and Mat-Su
Valleys. The fog is particularly dense across the Anchorage Bowl
and Matanuska Valley where a Dense Fog Advisory remains in place
through late this morning. Fog will remain the forecast challenge
through the next 24 hours for these same locations as the overall
synoptic pattern stagnates before the next storm system moves into
the Gulf. While the fog may lift and erode in some places later
this morning into the afternoon, the fog is likely to settle back
in this evening and linger into Monday morning.

The ridge has also ushered in a cold airmass with some of the
coldest temperatures of the season thus far, especially in
locations away from the fog and low cloud cover. Overnight low
temperatures in the Northern Susitna Valley have fallen into the
single digits with a few spots in the northern Copper River Basin
approaching ten below zero.

Northerly gap winds are on the increase this morning in the
typical locations, due to a strengthening pressure gradient
between the ridge and trough of low pressure extending from a
surface low near the Alaska Peninsula into Prince William Sound.
Locations such as Thompson Pass and Whittier could see periods of
blowing snow through this evening due to the gusty winds and
recent snowfall.

The next low to move into the western Gulf of Alaska is expected
later Sunday. Run to run model consistency is still somewhat poor,
but overall continues to track the low and its front south enough
through the central Gulf to mainly focus precipitation for Kodiak
Island and the immediate coastal around Prince William Sound.
Gale force winds with some embedded storm-force gusts appear
likely near the low and along the front. Precipitation type for
Kodiak may begin as snow later Sunday afternoon/evening, but then
transition towards rain by early Monday morning. If enough cold
air hold on along the coast, Kodiak City could see and inch or two
of snow with slightly higher amounts west of the city.

TM

&&


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

A strong front pushes against the Southwest Coast this morning,
bringing gusty winds and snow. Areas of blowing snow are expected
along the Kuskokwim Delta Coast and Western Capes this morning and
early afternoon, with up to 4 inches of accumulated snowfall
possible and visibility reductions to one half mile or less. Behind
the front, light waves of showery precip will move over the
Kuskokwim Delta Coast through tomorrow night. Light to moderate
precipitation and gusty southerly winds will also be present
through favored gaps and passes of the Alaska Peninsula tonight.

Another strong front moves into the western Bering Sea late Monday
night, bringing another (slightly weaker) round of gale to storm
force winds and precipitation to the Western Aleutians. The front
is expected to progress eastward through at least mid week,
weakening as it travels. Gales are likely to hold on as far as
the Pribilof Islands before weakening to small craft as they push
towards the Southwest Coast.

&&


.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

The main feature to begin the long term period is a broad
longwave trough over the Bering Sea and a large vertically stacked
low slowly moving along the coast of Kamchatka. Its strong high-
end gale to storm force front moving across the western and
central Aleutians early next week will begin to weaken by midweek
as it reaches the Alaska Peninsula and eastern Bering Sea. The
front pushes into the Southwest Alaska coast and inland Wednesday
into Thursday, spreading light snow across much of Southwest
Alaska. As warmer air pushes in behind the front, a transition to
a rain/snow mix along the coast will be possible.

Downstream of the system in the Bering, upper level ridging over
Southcentral looks to keep the weather relatively quiet to begin
the period. Models are hinting at a weak low spinning up in the
northern Gulf for Wednesday into Thursday, though confidence
remains low at this time on exact timing and placement. This
system will bring the potential for snowfall to the northern Gulf
coast as well as portions of inland Southcentral as what is left
of the front pushing across Southwest Alaska reaches Southcentral
and provides additional upper level support. Model agreement
continues to improve on a stronger low lifting out of the North
Pacific and tracking towards the eastern Aleutians and AKPen by
Friday. Widespread precipitation and gusty winds are expected to
accompany this low for the eastern Aleutians, AKPen, and Kodiak
Island as it continues into the Gulf for next weekend. Farther
west, yet another low and frontal system enters the western Bering
by the beginning of next weekend, bringing another round of
precipitation and elevated winds for the western Aleutians.

&&

.AVIATION...

PANC...LIFR to IFR conditions have continued overnight into this
morning in widespread fog streaming into Anchorage from the Mat
Valley and Knik Arm. IFR conditions will likely continue through
the rest of the morning as fog continues to move over the
terminal. Fog could lift to a low stratus deck and lead to
temporary improvement to MVFR ceilings and VFR visibility during
the afternoon. However, stratus will likely lower back into fog
again after sunset, bringing a potential return to IFR conditions
or lower through the overnight tonight. Light winds will persist
through the TAF period.

&&


$$

492
FXAK69 PAFG 091330
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
430 AM AKST Sun Nov 9 2025

.SYNOPSIS...
As a low pressure system works north through Southeast Alaska and
Western Canada today and Monday, scattered snow showers across
the Interior will shift northeast to along the Alcan Border and
Arctic Coast. Dry conditions will continue to build in across the
Western and Central Interior. As a result, best snowfall
accumulations will shift northeast of Fairbanks into the White
Mountains/Yukon Flats, along the Alcan Border, and Arctic Coast
where up to an additional 1-3" of snow is expected through Monday.
Clearer skies and drying conditions building in through midweek
will also support much colder conditions, as the coldest airmass
so far this season for most settles in over Northern Alaska.

Farther west, a frontal boundary will continue to lead to
strong winds across the Yukon Delta out towards St. Lawrence this
morning where gusts up to 50 mph have been observed. Winds here
will gradually decrease later today as the wind field expands
further north, supporting breezy winds along much of the West
Coast. Snow with this system will build in out of the southwest
today, expanding northeast towards the Seward Peninsula tonight
into Monday with accumulations up to around 1-3". An overlap of
breezy winds and snow could lead to areas of blowing snow at times
in this corridor. An overall colder and drier pattern will return
for much of this upcoming week, with best snow chances mid to
late week expected across Southwest Alaska.

&&

.KEY WEATHER MESSAGES...

Central and Eastern Interior...

- Light snow continues across the Eastern Interior today as best
chances shift east to along the Alcan Border. Light additional
accumulations expected through tonight, with around 1-3" from
Northway to Eagle.

- Cloudy skies give way to clearer skies today, supporting colder
temperatures and areas of dense fog as conditions turn
predominantly dry for the week ahead.

- Highs today and Monday in the single digits and teens with lows
in single digits above and below zero and teens.

- Colder temperatures continue to build in mid to late week as
highs drop to the single digits above and below zero with
widespread lows below zero. Coldest spots could see double digit
below zero lows.

West Coast and Western Interior...

- Frontal boundary continues to lift north along the West Coast,
leading to elevated E/SE winds with up to Gale Force winds this
morning from the Yukon Delta to St. Lawrence Island. Elevated
water levels above the normal high tide line possible across the
West Coast, highest around the YK Delta.

- Snow chances along this front continue to progress north today
into tonight, reaching as far north as the Seward Peninsula as
the Northwest Coast remains predominantly dry. Snow
accumulations further south up to around 1-3" through Monday
night.

- Conditions remain dry across the Western Interior with clearer
skies supporting areas of dense fog/low stratus and cold
temperatures.

- Dry conditions return Tuesday along the West Coast outside of
isolated snow showers further south, ahead of another front
building into Southwest Alaska Wednesday into Thursday with
another round of snow and breezy winds.

- Highs in the teens and 20s with lows in the single digits above
and below zero and teens. Warmer conditions on St. Lawrence
Island with highs in the 20s and 30s with lows in the 20s.
Temperatures trend colder overall midweek.

North Slope and Brooks Range...

- Light snow continues across the North Slope and Eastern Brooks
Range today through Tuesday. Additional accumulations through up
to around 1-3", locally higher across the Eastern Arctic Coast
around 3-5".

- Northeast winds prevail along the Arctic Coast through midweek,
strongest further west from Utqiagvik to Point Hope.

- Dry conditions return region wide Tuesday night into Wednesday
as a colder and drier airmass settles in overhead.

- Highs early this week in the teens and 20s across the Arctic
Coast and single digits and teens for the Arctic Plains and
Brooks Range, with lows in the single digits and teens to below
zero zero further inland.

- Colder temperatures continue to build in mid to late week as
highs drop mostly to the single digits above and below zero with
widespread lows below zero. Coldest spots could see double digit
below zero lows.

&&

.FORECAST ANALYSIS AND DISCUSSION...Today through Tuesday Night.
Early morning satellite imagery shows a 975 mb low moving onshore
into Southeast Alaska as an occlude front ejected from a 960 mb
low in the Western Bering Sea continues its progression northeast
across Southwest Alaska. Moisture from that low in the Gulf of
Alaska will continue to lift north through Western Canada and
along the Alcan Border, supporting light snow continuing across
the Eastern Interior as the Western and Central Interior trend
dry. Additional snow accumulations are expected to remain light,
highest along the Alcan Border from Northway to Eagle around 1-3".

Across Western Alaska, a broad frontal boundary will occlude into
a 980 mb low just offshore of the Yukon Delta today, supporting
elevated winds and snow chances across the West Coast. Wind gusts
have been observed up to 50 mph on St. Lawrence Island and the
Yukon Delta, which will gradually lessen later today as the wind
field expands to encompass much of the West Coast with breezy E/SE
winds through Monday. Snow will continue to progress north today
into tonight, reaching as far north as the Seward Peninsula as the
Northwest Coast remains predominantly dry. Snow accumulations
further south in this corridor up to around 1-3" through Monday
night. An overlap of breezy winds and snow will lead to areas of
blowing snow at times in this corridor.

An overall colder and drier pattern is then expected to return
for much of this upcoming week, with best chances for snow through
midweek along the Arctic/West Coast and Eastern Brooks Range as
conditions turn predominantly dry across much of Northern Alaska.

Coastal Hazard Potential Days 1 and 2...Elevated water levels
above the normal high tide line possible across the West Coast,
highest around the YK Delta around 1-3 feet. A Special Weather
Statement has been issued for the YK Delta to highlight this.

&&

.EXTENDED FORECAST DAYS 4-7...Wednesday through next Saturday.

Cold and mostly dry conditions are expected to continue across
Northern Alaska through next weekend as the coldest airmass so
far for most this season builds in. Widespread sub zero low
temperatures are expected with coldest spots reaching the double
digits below zero. Warmest locations during this timeframe will be
across Southwest Alaska, which is also where ensemble model
guidance remains in good agreement on snow chances returning for
Wednesday and Thursday. Long range models continue to show several
low pressure systems tracking through the Northern Pacific and
Bering Sea for mid to late next week, keeping the idea of
increasing snow chances around later in the week. Overall,
conditions look to remain cold and on the drier side this week for
our region as storms generally favor a further southerly track as
high pressure remains in place over the Arctic.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801-802.
Heavy Freezing Spray Warning for PKZ801-853.
Heavy Freezing Spray Warning for PKZ802-803.
Small Craft Advisory for PKZ803-856.
Heavy Freezing Spray Warning for PKZ804>812-855>858.
Small Craft Advisory for PKZ804-807.
Small Craft Advisory for PKZ805-806-852-853.
Small Craft Advisory for PKZ810.
Small Craft Advisory for PKZ811-812-857-858.
Heavy Freezing Spray Warning for PKZ813-859.
Heavy Freezing Spray Warning for PKZ814.
Gale Warning for PKZ816-817-850-854.
Heavy Freezing Spray Warning for PKZ850.
Gale Warning for PKZ851.
Heavy Freezing Spray Warning for PKZ852.
Heavy Freezing Spray Warning for PKZ854.
Heavy Freezing Spray Warning for PKZ860.
&&

$$

MacKay

513
FXAK67 PAJK 091828
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
928 AM AKST Sun Nov 9 2025

.UPDATE.../To add the 18Z aviation discussion/...

.SYNOPSIS...

Key Messages:

- A very active late weekend in SE AK with heavy rain across most
of the panhandle, high wind gusts in the southern panhandle, and
heavy snow on the Haines and Klondike highways.

- Low pressure sliding north will spread moderate to heavy precip,
mostly rain, to SE AK through Sunday afternoon.

- Wind gusts upwards of 60 mph have been observed overnight in the
southern panhandle and will start to diminish this morning.
Elevated wind gusts around 30 to 50 mph possible for the rest of
the panhandle as well as the low moves north Sunday.

- Heavy snow is possible in the far northern panhandle ahead of
the low. But this part of the forecast has high uncertainty.

&&

.SHORT TERM...A strong area of low pressure is moving N through
the eastern gulf this morning. As of 5 am the low center is around
55N 136W with the associated front stretching SE along the outer
coast to Haida Gwaii. Precipitation has spread over the entire
panhandle at this point (except for areas W of Cape Fairweather)
with most areas seeing rain. It has been rather heavy in the
southern panhandle with consistent hourly rain rates up to 0.3"
per hour overnight. In the north, enough cold air has invaded at
lower levels that Hoonah, Haines, the Haines Highway, and the
higher elevations of the Klondike Highway are seeing accumulating
snow (likely just a few inches so far based on webcams). There is
also a rain snow mix being observed in the Mendenhall Valley of
Juneau this morning, but no observed accumulations. The low is
expected to trek N to near Cross Sound by afternoon before passing
into the southern Yukon this evening.

Precip is expected to continue today and for the north intensify
as the main low center continues its northward trek. Winter storm
warnings remain up for the Haines and Klondike highways as snow is
continued to be expected today with the highest accumulations
occurring during the day today. Meanwhile the heavier rain for
the south and central panhandle is expected to start a gradual
diminishing trend later this morning. By evening much of the
heavier rainfall will be moving east of the area (except for
Hyder) and should mostly be done by late Sunday night. Still we
expect around another inch or two of rainfall for most areas
through Sunday evening. This will be on top of the 1.5 to over
three inches that has already fallen over the southern panhandle
overnight. The flood watch remains up at the current time.

Winds have also been frisky. Wind gusts to 60 to 65 mph have been
observed in the southern panhandle at sea level overnight and
occasional gusts to 55 mph are still occurring at Hydaburg and
Metlakatla. Additionally gusts to 35 mph have been observed
farther north at Wrangell, Petersburg, and Sitka early this
morning. High wind warnings are still up for the southern
panhandle this morning though the gusts are starting to show signs
of diminishing and should gradually do so through the morning. The
stronger southerly winds are expected to spread north as the low
moves north today, eventually even causing Lynn Canal to switch
from its current N 25 kt to a S 25 kt late this afternoon. Of
concern is the area around Cross Sound when the low center moves
over that area this afternoon. This low is following a similar
track to the storm that caused damage at Elfin Cove earlier this
fall. It is not as strong as that storm, but it is expected to
bring a period of gusty winds (40 to 55 mph gusts) and an abrupt
wind shift (E to W in a short time period) to the Cross Sound area
this afternoon. This area will be closely watched today as the low
gets closer.

.LONG TERM...While the big story is in the short term forecast, the
panhandle will not be out of the woods just yet by the start of next
week. A gale force low is expected to develop along an elongated
trough extending from a system off of Kamchatka. This low will
develop southwest of the Alaska Peninsula, moving eastward into the
northern gulf Monday, pushing a gale force front into the panhandle
sometime Monday afternoon. This low will quickly become cutoff from
any upper level steering flow and also any upper level support, as
an amplifying trough in the jetstream will move over the gulf
Tuesday, overtaking the surface low. Overall this will lead the low
to be vertically stacked and likely occluded, or near that phase,
when the front pushes into the panhandle. This weakening of the
system, combined with the lack of upper level steering, has caused
deterministic models to have varying tracks for this feature Tuesday
into Wednesday. When checking ensemble model guidance, the general
consensus, aside from the weakening trend, is for the system to slow
down, and then lift northward into the central or northeast
panhandle before dissipating. During this whole time though, it
would continue to bring onshore flow to the panhandle with light to
moderate showers and some possibility for isolated thunderstorms
along the outer coast in the post frontal environment Tuesday
evening. Beyond this early week system, the outlook looks fairly
benign due to the aforementioned significant dip southward in the
jetstream through midweek. It will not be until later in the week
that the jetstream rebounds and another short wave disturbance may
spin up in the vicinity of Prince William Sound, with no significant
impacts expected from it at this time.

A band of moderate to heavy precipitation will accompany this front,
with heaviest rates along the outer coast due to orographic
enhancement. Overall 24 hour totals from from Monday morning through
Tuesday morning look to range from 1 to 2 inches as of this
discussion. For the far northern panhandle, the Haines and Klondike
Highways will likely remain cold enough to receive more snow
accumulation, with the prospect of snow for the cities of Haines
and Skagway being much more dubious. Stay tuned for further
refinement of the early week forecast as the weekend progresses.

&&

.AVIATION.../Until 18Z Monday/...An impactful area of low pressure
it pushing its way northward, through southeast Alaska today.
Primarily MVFR conditions are in store for the period with dips
into IFR for areas that see heavier precipitation this morning, &
areas that receive heavier rainfall & areas in the far northern
panhandle, primarily around the Icy Strait corridor & northward,
that receive snowfall, today. Breezy SFC wind conditions out of a
northerly direction ahead of the low & out of a southerly
direction behind it are anticipated through the TAF period. A
frontal system approaches the region from the southwest on Monday,
which will end up lowering flight conditions & increasing winds,
once again. LLWS magnitudes up to around 50 kt continue to be in
store out of a generally southerly direction centered up at around
2 kft, today, with the highest values the farther south in the
panhandle you go.

&&

.MARINE...Outside Waters: A strong low near 55N 136W is moving in
a generally northward direction and is expected to be near Cross
Sound (still moving north) by this afternoon. E of the low track,
gale force southerly winds to 40 kt are blowing with seas to 20 ft
observed just off Prince of Wales Island. W of the low track,
winds are gale force northerly (to 35 kt) with seas of around 15
kt and gradually diminishing the farther W you go. These
conditions are expected to transition to mostly W gale force
winds (35 kt) for most areas by this afternoon as the W flow on
the south side of the low takes over as the low moves into the
Yukon. Into tonight expect a diminishing trend in wind and waves
and a shift to southerly for wind direction before the next front
arrives Monday from the W bringing more gale force winds.

Inside Waters: The inside waters are showing two faces with the
southern channels seeing gale force (to 45 kt, especially in
Clarence Strait) southerly winds while the north has northerly
winds this morning. The stronger southerly winds in the south have
not gotten any farther north then Petersburg and Kake as of 5 am.
The north meanwhile has been seeing E and N winds to 25 kt
depending on where you are with northerly pressure gradient flow
successfully overwhelming the synoptic flow so far. That is
expected to change through the day with the southerly winds
spreading all the way through the inner channels by late this
afternoon, especially when the gulf low jumps into the southern
Yukon and the northerly pressure gradient flips to a southerly
gradient. Southerly winds will likely reach 25 to 30 kt in the
north this evening. Seas will mainly range around 4 to 6 ft with
higher seas near ocean entrances. Winds and seas should then start
a gradual diminishing trend late tonight into early Monday before
starting to increase again Monday afternoon as the next front
pushes into the panhandle.

&&

.HYDROLOGY...An atmospheric river continues to dump heavy to
moderate rain for many areas of the panhandle. Heaviest rainfall
has been over the southern panhandle with upwards of 3 inches
having fallen in some places overnight. Forecasted PWAT
(precipitable water) values continue to be impressive for this
time of year, with high resolution guidance indicating near 1.2
inches of PWAT. "Normal" this time of year is near 0.5 inches.
Associated with this deep plume of moisture will be dynamics able
to effectively squeeze this moisture out, through a negatively
tilted trough and moist southerly flow interacting with terrain.
The higher terrain in the southern region is situated very well to
receive near 8 inches of rain through Sunday night, with near 5
inches storm total rain for sea level communities.

Through coordination with the AK River Forecast Center, we are not
concerned with flooding of major rivers. The main threat continues
to be flooding of areas with poor drainage and ponding of water
in more urban environments. Another major factor is a
combination of high wind and heavy rainfall, bringing chances for
isolated landslides in Prince of Wales, Ketchikan, and Metlakatla

The rain is expected to start diminishing Sunday afternoon and
will have mostly moved off to the east by Sunday night.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning until 6 PM AKST this evening for AKZ318.
Winter Storm Warning until 3 PM AKST this afternoon for AKZ319.
Strong Wind until 9 PM AKST this evening for AKZ322.
Strong Wind until 6 PM AKST this evening for AKZ323-327.
Strong Wind until 3 PM AKST this afternoon for AKZ329.
High Wind Warning until noon AKST today for AKZ332.
MARINE...Gale Warning for PKZ022-031>036-641>644-661>664.
Small Craft Advisory for PKZ012-013-021-053-651-652-671-672.

&&

$$

SHORT TERM...EAL
LONG TERM...STJ
AVIATION...JLC
MARINE...EAL
HYDROLOGY...EAL

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