958
FXAK68 PAFC 301315
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
515 AM AKDT Tue Sep 30 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
The forecast generally remains on track with some improvements in
the model agreement for the midweek storms. Currently, the low
that had been over the Gulf of Alaska is now exiting southeast,
leaving mostly zonal flow in the upper levels. The trough to the
north is moving across the Alaska Range and into the Copper River
Basin this morning. Generally quiet weather conditions can be
expected for today for most of the region, though snow showers
will become a bit more widespread, especially across the Tok
Cutoff Road, from Slana north through Mentasta Pass through the
rest of this morning. Light snow accumulations, on the order of
around an inch, are possible in this area.
The coolest overnight low temperatures will shift east for
Wednesday morning as thicker cloud cover moves in from the west
and starts to moderate surface temperatures by a few degrees.
Although slight differences remain in the models with timing,
overall consensus is beginning to align. A front arrives to the
western Gulf early Wednesday morning with a surface low forming in
the northern Gulf later in the day. Most places west of Prince
William Sound will see some precipitation by early to mid-morning
Wednesday. The exact amount, especially in the lee of the
mountains, will be dependent on the orientation of the flow aloft
and the extent of southerly gap winds. Another round of
precipitation will likely spread north across most of Southcentral
Thursday as the surface low tracks into Prince William Sound.
Precipitation looks to diminish for most locations by Friday.
-TM/Rux
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3/Today through Friday)...
Currently, as of the morning, clear skies are prevalent across
the southwest Mainland as a ridge passes through the region. This
is allowing temperatures to once again drop to the mid-20s.
Meanwhile in the Bering, a front from a large low moving into the
Bering Strait is causing a line of small craft winds and
precipitation to affect from St. Matthew Island, down through the
Pribilofs, to north of the Andreanof and Fox Islands. This front
will progress eastward over the course of the day and will arrive
in the mainland by this (Tuesday) afternoon. The front will bring
warmer air along with it, so low temperatures in the mainland will
not be as cold Tuesday night.
Wednesday has the upper trough slide down into the mainland,
allowing for continued chances for precipitation. A north Pacific
low will barely "scrape" the Andreanof Islands before moving
southeast, causing a brief period of higher southerly winds. The
low will, however, will interact with the aforementioned trough,
allowing for a long uninterrupted line of rainfall from Adak to
the Alaska Peninsula. A ridge will build into the western
Aleutians by the afternoon and will quickly progress eastward,
reaching the mainland by Wednesday night/early Thursday morning.
Rain chances will quickly diminish and winds will become more
westerly all across the Bering and into the mainland. Cold air
advection from the trough that passed the mainland will allow for
night time temperatures to drop into the 30s as skies clear.
Temperatures are not expected to be as cold as the previous event.
Friday sees a North Pacific low move up into the Western and
Central Aleutians by the afternoon. Gusty gale force to storm
force winds and heavy precipitation are expected with this low.
Looking ahead to the weekend has the low continuing through the
Eastern Bering, eventually ending up west of Nunivak Island by
Sunday. This could cause issues with coastal flooding in the
Kuskokwim Delta Coast as south-southwesterly winds impact them.
There is still some uncertainty with this event, so changes are
likely as the low continues to develop. Continue to monitor the
forecast for future updates on this low.
-JAR
&&
.LONG TERM FORECAST (Days 4 through 7: Friday through Tuesday)...
The end of the workweek starts out with a Chukotsk low broadening
out into a trough of low pressure over northern and central
Alaska by Friday, with multiple weak embedded lows. Additionally,
a strong system approaches the western Aleutians, evolving into a
dominate Bering Sea storm. This system intensifies by Saturday,
sprawling across the Bering and moves towards Nunivak Island by
Sunday, possibly causing some minor coastal issues along the
Kuskokwim Delta with steady southwesterly onshore winds as this
system continues on towards Norton Sound before weakening sightly
at the of the forecast period. A separate low near the Kenai and
Alaska Peninsula Thursday weakens into a broad trough by Saturday
before being absorbed into the bering storm`s wind field by Sunday
and fully merges with it by Sunday and pushes a frontal system
into the western Gulf of Alaska by monday afternoon.
The major models predict the Bering Sea system over the weekend.
The European and Canadian models continue to be in agreement
trough day 7, with the CMC slightly stronger and faster. The GFS,
however, is still the slight outlier with its earlier forecast
period moderately different than its counterparts but improves
towards the end of the forecast period but still is not in full
agreement with the other 2. The Canadian is currently favored as
it leads the trend of the system moving south and east, ending up
weaker and closer to the Yukon Delta towards the end of the
period.
-DD
&&
.AVIATION...
PANC...VFR conditions, and light and variable to light northerly
winds, will persist. There is a chance for vicinity fog this
morning, with chances diminishing after 16Z.
&&
$$
806
FXAK69 PAFG 301234
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
434 AM AKDT Tue Sep 30 2025
.SYNOPSIS...
The coastal storm season is continuing to brew up as multiple
lows are being tracked along the Bering in the short-term and
extended portions of the forecast. An Arctic trough continues to
shift NE, and out of the Interior. This will continue to bring
snow showers across the Eastern Interior through late Tuesday
night. A frontal system will be moving into the state tonight,
from the Bering, from an upper-level low moving east out of
Siberia. This will set up a familiar "troughy" pattern across the
West Coast and southwesterly flow across eastern portions,
resulting in widespread rain and snow showers through the end of
the week.
&&
.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Scattered rain and snow showers across the Eastern Interior
today, shifting northeast by this afternoon.
- Clear conditions expected as the shortwave moves east, setting
up low temperatures in the low to mid 20s across the Interior
Tuesday night into Wednesday.
- Next system moves in from the Bering Sea, Wednesday into
Thursday, with light rain and snow showers across the Interior
with mostly rain likely across the Tanana Valley.
- Southerly winds increase through the Alaska Range passes on
Friday and continue through the weekend. Gusts of 30 to 40 mph
should be common through both passes with stronger gusts to near
or above 50 mph possible through Windy Pass late on Saturday.
West Coast and Western Interior...
- Dry conditions and mostly clear skies allow for one more cool
night before increasing clouds and a warmer air mass result in
highs mainly in the low 40s and lows mainly in the 30s.
- Strong SE winds up to 55 mph are possible for St. Lawrence
Island midday, today. A 6-12 hour period of strong SE gusts of
35 to 45 mph shifts northeast reaching the Seward Pen this
afternoon then the Kotzebue Sound late tonight.
- A frontal boundary tracking northeast along the West Coast late
Tuesday through Wednesday brings a few hours of steady rain and
higher elevation snow followed by scattered showers through the
end of the week. Mostly rain showers expected from the YK-Delta
to McGrath.
North Slope and Brooks Range..
- Scattered snow showers through the day across central and
eastern portions of the North Slope and Brooks Range with sea-
effect snow showers near the northern Arctic Coast through
Wednesday morning.
- Western portions of the region remain dry until Wednesday when
light snow moves into the western Brooks Range, then becoming
more widespread Thursday into Friday.
- Highs in the low to mid 30s along the Arctic Coast, 20s across
most of the North Slope and foothills with teens in the Brooks
Range mountains. Overnight lows mainly in the upper teens and
20s with single digits to lower teens in the Brooks Range.
&&
.FORECAST ANALYSIS AND DISCUSSION...
Little to no change was made to the overall forecast. The current
Arctic trough over the E/NE portion of the state will continue to
ride up the Al-Can border through early Wednesday morning. This
will continue to provide snow showers along these areas until the
system moves out. The trough is getting pushed out from a ridge
that continues to move east from the Bering and across the West
Coast. This ridge will continue to push across across the Interior
and into the NE Arctic Coast by Wednesday afternoon. The
progression of this ridge is due to a wide, closed 520 decameter
low moving out of Siberia. As it progresses east across the
Bering, it will turn into more of a trough-like feature that dips
down from the Arctic and across the Aleutians. The frontal system
associated with this low will bring widespread gale force winds
across the Bering, starting around St. Lawrence Island, today, and
moving up to the Chukchi Sea coast by Wednesday night. Along with
this, widespread rain/snow showers over the Seward Peninsula,
snow showers along the Western Brooks Range and NW Interior, and
rain showers across the YK Delta to the Upper Kuskokwim. This
front will continue to push across the Interior, setting up
sufficient SW flow across the eastern portion of the state. This
will bring a chance for more snow showers across the Northern
Interior. These snow showers will be rather wet, as the system
will be tapping into a moist airmass from the northern Pacific.
The heaviest amounts of snow are expected between the Steese and
the Dalton Highway, Thursday night into Friday, in the White
Mountains with totals between 5" and 9" inches possible. This flow
will also continue to bring more snow across the Alaska Range
with totals between 2" and 4" along the Parks and Richardson
Highways.
In regards to model agreement, all of them are in friarly good
agreement with timing, strength, and positioning of the main
features. Looking deeper into the model runs, these most recent
ones just started showing the heavy snow in the White Mountains.
As of right now, the 50th percentile and mean of the NBM are
around 5", with the 75th and 90th percentiles showing totals
around 9".
&&
.HYDROLOGY...
No concerns at this time.
&&
.EXTENDED FORECAST DAYS 4-7...
The coastal storm season is beginning to spin up with global
models showing multiple rounds of storms in the extended. Starting
with round one, beginning around Friday night into Saturday, with
a low moving eastward, just North of the Aleutians. All of the
models are showing signs of ridging building up over the eastern
portion of the state at the same time, resulting in southerly flow
over the West Coast and allowing the storm to track up along the
coast. As per usual, models are disagreeing with the ridge
breakdown, which will be the main feature that helps determine the
overall path of the system. As of right now, the ECMWF is showing
the quickest breakdown, turning the system into more of a
shortwave feature and moving across the southern Alaska Coast.
Other models keep the ridge built up, which would allow for a more
northward track up the West Coast. A stronger system begins to
move up from the Bering mid-week, which models are currently
showing a vast variety of tracks. However they all show are
showing the potential to track toward the Seward Peninsula.
Trends will continue to be monitored closely on all of these
systems as the slightest of track deviations can have various
results.
Coastal Hazard Potential Days 3 and 4...None
Storminess increases along the West Coast over the next week, but
high water levels are not expected through Thursday. A seasonably
strong low pressure system the West Coast late this week. There is
potential for elevated water levels within a southwesterly wind
regime across the YK Delta and Norton Sound area this weekend.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801-807-856-858.
Small Craft Advisory for PKZ802.
Small Craft Advisory for PKZ803-852.
Small Craft Advisory for PKZ804.
Gale Warning for PKZ805.
Gale Warning for PKZ806.
Small Craft Advisory for PKZ808>812-855.
Gale Warning for PKZ816.
Gale Warning for PKZ817-850.
Gale Warning for PKZ851.
Gale Warning for PKZ853.
Gale Warning for PKZ854.
Gale Warning for PKZ857.
&&
$$
Twombly
814
FXAK67 PAJK 301817
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1017 AM AKDT Tue Sep 30 2025
.UPDATE...Update to the discussion to include the 18z TAFs.
&&
.PREV DISCUSSION......ISSUED AT 538 AM AKDT...
SHORT TERM...
Key Points:
- A low pressure system moves into the far southern gulf this
morning keeping clouds over the southern panhandle.
- Ridging begins to develop over the gulf today into Wednesday
allowing for clearing skies and drier conditions over the
panhandle.
Details: Satellite imagery is beginning to show a low pressure
system slowly moving north that will eventually reach the far
southern Gulf of Alaska. With this low, the southern panhandle will
see increased cloud cover with a slight chance of rain through
Tuesday. Any rain over the southern panhandle is highly likely to
remain light. The northern and central panhandle will have a bit of
a different story as a ridge builds over the gulf. This developing
ridge will allow for drier conditions with decreasing cloud cover.
Some areas of fog may develop this morning for the central panhandle
as the sun begins to rise.
Land winds will remain mainly light with the strongest winds located
over the southern panhandle as the low moves north. Areas on Prince
of Wales Island and near the Ketchikan area are likely to see winds
increase to 10 to 15 mph for land areas with infrequent gusts around
20 mph. Winds along the southern inner channels will also increase
to fresh breezes around 15 to 20 kts as the north to south oriented
pressure gradient increases. Overall the strongest winds are
anticipated late this morning into this afternoon.
LONG TERM...For the start of the long term, high pressure
continues to remain over the area for Wednesday. With high
pressure over the area, and lower pressure to the south, outflow
winds are expected to develop for north/south oriented sections.
These outflow winds are expected to dissipate as high pressure
moves closer to the coast weakening the pressure gradient. This
high pressure is then expected to continue to shift to the east
for Thursday as low pressure moves into the western gulf from the
north west. This low is expected to move out of the Bering Sea
before moving into the eastern Gulf. With cooler air aloft and
snow levels already down to 3,500-4,500ft during this time, the
termination dust line will likely continue to work down the
mountainside. The possibility of snow mixing down to White Pass is
possible and could result in a dusting to minor accumulations for
this area especially during heavier periods of precipitation
Thursday into Friday. Everywhere below 3,000ft is expected to
continue to see rain but temperatures will continue to be in the
40s to 50s during this time. Headed into the weekend, high
pressure returns across the Gulf which will introduce mostly
benign weather for the with the exception of some increased winds
in certain parts of the panhandle. Long term guidance points
towards a near normal trend for this time of the year. Although
places to the north will likely see a higher potential for above
normal temperatures and above normal precipitation. While farther
to the south, there is a greater chance for near normal
temperatures but potentially below normal precipitation for the
next one to two weeks.
AVIATION...Flying conditions this morning continue to be nice
overall for most of the panhandle. Some areas of lowered ceilings
and or visibility exist across the panhandle, but most
observations continue to show VFR conditions. These conditions are
expected to persist throughout the day as the areas of LIFR fog
are expected to dissipate throughout the morning allowing for
improving conditions. Headed into this evening, the potential for
fog redeveloping will need to be looked at more as high pressure
continues to move into the area. Otherwise today looks to be a
good flying day overall.
&&
MARINE... Inner Channels: Winds today become
northerly across the inner channels as a low moves toward the
southern panhandle, and ridging develops over the gulf. Wind
speeds will increase to fresh breezes around 15 to 20 kt out of
the north for some north to south oriented channels as the
pressure gradient increases. The strongest winds will be located
over the southern inner channels and near Point Couverden. Timing
of the strongest winds is late Tuesday morning into Tuesday
afternoon. Wind speeds will Wednesday across the inner channels as
the ridge progresses eastward and the inner channel pressure
gradient weakens.
Outside Waters: Fresh to strong breezes of 20 to 25 kts will
continue to develop in the southeastern gulf waters this morning as
a low moves into the southern gulf. The strongest winds will be to
the west of Haida Gwaii and along the southeastern gulf. These fresh
to strong breezes will continue and slowly move northward along the
eastern gulf Tuesday as the ridge pushes eastward. As the ridge
develops over the gulf, winds will become northerly to
northwesterly. As the ridge becomes more prominent, Tuesday into
Wednesday, seas will build to 5 to 7 ft along the northeast gulf and
8 to 12 ft along the central to southeast gulf.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ641>644-661>664.
&&
$$
SHORT TERM...EAB
LONG TERM...SF
AVIATION...SF
MARINE...EAB
Visit us at http://www.weather.gov/Juneau
