093
FXAK68 PAFC 171313
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
513 AM AKDT Mon Aug 17 2026
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
Key message:
* Flood Watch is now in effect for the Susitna Valley for areas
upstream of Lake Creek and Yentna Rivers through Wednesday
afternoon. Rainfall totals of 2 to 4 inches expected. Near the
Parks Highway, from Willow through Talkeetna, 1 to 2 inches of
rainfall expected.
Discussion:
The large low that has been tracking through the Bering Sea is now
in Southwest Alaska. The main front associated with it has swept
through Southcentral and is in the Interior of the state as of
early this morning. The result is that there are strong pressure
rises behind this front that are spurring gusty southerly winds
up Cook Inlet and also though the Copper River Basin gap areas.
Southcentral is also in the showery sector of the low with
multiple shortwaves kicking off periods of showers. Throughout the
day there should be a slow diminishing of both the winds and in
shower activity for most of the area. The Susitna Valley is the
one region that will likely really hold onto the rainfall as the
south-to-southwest flow aloft is favorable for upsloping along the
Alaska Range and Talkeetna Mountains. In addition, the Susitna
Valley is closer to the upper low center which is keeping it more
unstable as well. This is a major reason there is a Flood Watch
in effect for some portions of the Susitna Valley.
By Tuesday, the upper level low will ave tracked northeastward
though the Interior. However, as it usually the case in August,
the large longwave trough remains over the Bering Sea and another
upper level low embedded in this trough is ready to replace the
old low. This will allow less shower activity for tuesday as the
second low is sill out in the Bering Sea, but by Wednesday it
should be moving into Bristol Bay and bring more widespread
rainfall into Southcentral.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(Days 1 through 3: Monday through Thursday afternoon)...
An active pattern continues across Southwest Alaska, the Bering
Sea and Aleutians through the middle of the week as a series of
upper-level disturbances track across the region. A compact upper-
level low near the Alaska Peninsula and eastern Aleutians today
will gradually lift north and east, while another upper- level low
approaches the western Aleutians from the North Pacific.
For today, the upper low near the Alaska Peninsula (AKPEN) will
continue to support areas of rain and gusty winds across portions
of Southwest Alaska, the eastern Aleutians and AKPEN. Farther
west, the next system approaches the western Aleutians, with
increasing winds and rain spreading into the region.
By Tuesday, the first upper low begins to weaken as it lifts
farther into Southwest Alaska, while the western Aleutian system
becomes the more dominant feature. This low and its associated
front will progress eastward along the Aleutian Chain, bringing
another round of rain and gusty winds from west to east. Periods
of low clouds and fog will also remain possible across the Bering
and Aleutians.
Wednesday into Thursday, the upper low continues eastward toward
the eastern Aleutians and AKPEN. This will maintain unsettled
conditions across much of the Aleutians and southern Bering , with
rain and gusty winds gradually shifting east. Increasing chances
for precipitation will spread toward Bristol Bay and portions of
Southwest Alaska as the system approaches. Model agreement
decreases somewhat with the exact position and strength of the low
later Wednesday into Thursday, the overall pattern favors
continued unsettled conditions through the end of the period.
LM
&&
.LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)...
The long-term period starts with an upper-level low situated over
Bristol Bay and a surface low over the Alaska Peninsula or
extreme western Gulf of Alaska. These features will bring rain
across the Southern Mainland through Thursday.
A stronger and potentially more impactful storm for Friday and
the weekend across the Southern Mainland begins to take shape
upstream in Kamchatka Thursday. A strong shortwave digs south from
Siberia to the northern Bering Sea by Friday morning. A gale-
force surface low Will move into the northern Bering around St.
Matthew Island to St. Lawrence Island by Friday morning. Moderate
to heavy rain is likely to overspread the Southern Mainland,
starting first with Southwest on Friday, and working east to
Southcentral through Saturday. Showers continue across the
Southern Mainland on Sunday as the low works farther into Western
Alaska.
Trends with this system, deviations in track and strength, will
have to be watched closely when it comes to determining coastal
impacts along the Kuskokwim Delta Coast. Taking a quick look at
ensemble data, the GFS and Canadian ensemble suites are more
in line with each other with a slower and stronger solution. The
European ensemble guidance is a little faster with the storm track
which has the system moving inland of Western Alaska by Friday;
this solution also features a weak system. Regardless, there will
be a push of on-shore flow with this system, it will be a matter
of its magnitude which will be ironed out in due time.
Farther out west, embedded shortwaves moving from west to east
atop a strong North Pacific ridge will keep the Aleutian Chain
showery at times for Thursday. The northern Bering low`s front
will also sweep across the Chain for Friday and make it to the
Alaska Peninsula (AKPEN) for Friday night into Saturday. The
southern AKPEN will see the wettest conditions with this front
Friday night into Saturday as it only grazes the Aleutian Chain
Friday. The AKPEN will remain showery for Saturday and Sunday as
flow turns northerly behind the northern Bering low which is
moving inland by then. A surface ridge works in across the Central
and Eastern Aleutians Saturday and Sunday as shortwave and
another round of showers approaches the Western Aleutians from the
North Pacific.
&&
.AVIATION...
PANC...VFR conditions are expected to remain through the TAF
period, though periods of showers may causing ceilings to dip to
MVFR at times. Gusty southerly winds will persist through the day
and start to diminish some overnight. As the surface winds and
winds aloft are both from the south, low level wind shear is no
longer expected.
&&
$$
580
FXAK69 PAFG 180010
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
410 PM AKDT Mon Aug 17 2026
.KEY MESSAGES... Central and Eastern Interior...
-Gusty winds continue through Monday night. A High Wind Warning
is in Effect for Isabel Pass through 12 AM Tuesday for wind
gusts up to 70 mph.
-Heavy precipitation is expected to continue in the Central Interior
Monday morning through Tuesday morning. Expect 24 hour accumulations
of up to 2 inches at higher elevations along the Koyukuk and Dalton
Highway Summits, as well as for places like Tanana and Hughes.
Rainfall remains lighter (<0.25 inches) from Fairbanks east through
Wednesday when post- frontal convective showers extend into the
region, especially over higher terrain. Chances for an isolated
thunderstorm are possible in the White Mountains Monday afternoon,
as well as potentially later in the week.
-Temperatures continue to cool with widespread highs in the upper
50s/low 60s expected in the region (except for the Upper Tanana
Valley, which stays in the upper 60s) by Wednesday. High
temperatures remain more moderate for the foreseeable future.
West Coast and Western Interior...
-Heavy rainfall is expected into Tuesday for higher elevations along
the Koyukuk, with accumulations up to 2 inches of rainfall possible
between Galena and Huslia by Tuesday morning.
This rain could potentially bring sharp rises along the Koyukuk
and nearby tributaries. No flooding is anticipated, but smaller
creeks and streams could become bankfull.
-Temperatures cool off significantly as a front moves through on
Monday evening. Widespread highs will be in the mid 40s/low 50s on
the coast and mid 50s/low 60s inland by Wednesday afternoon.
Temperatures remain on the cooler side for the rest of the week.
-Northerly wind gusts remain elevated in the Bering Strait on
Tuesday, with gusts up to 35 mph possible. Wind gusts diminish on
Wednesday to 15 kt.
North Slope and Brooks Range...
-1-2 inches of precipitation is possible along the southern slopes
of the Central Brooks Range by late Tuesday. This rain could
potentially bring sharp rises along the Koyukuk and nearby
tributaries. No flooding is anticipated, but smaller creeks and
streams could become bankfull. On the north side of the range, areas
in the Eastern Arctic Plains/Coasts could see accumulations between
0.5 inches and 1 inch.
-High temperatures will be in the mid 40s/mid 50s over the plains
and in the mid/upper 30s along the coast through most of the week,
before increasing to the upper 50s/lower 60s on Thursday.
&&
.SYNOPSIS...
A broad area of troughing over Northern Alaska continues to produce
a wide variety of impacts. For the Central and Western Interior,
alongside areas south of the Brooks Range moderate to heavy rain
will fall through Tuesday as a front within a broader decaying area
of troughing stalls, bringing upwards of 1 to 3 inches of rain
before finally dissipating. Meanwhile, strong downsloping winds in
the eastern Alaska Range have brought gusty conditions and kept
drier weather lingering for locations in the Forty Mile Country.
Chances of thunderstorms meanwhile linger across parts of the
eastern Interior, including the Yukon Flats.
Chances of rain will linger through the week, though showers in the
eastern interior will be less widespread and more isolated in
nature. Another system arriving late in the week will bring another
round of widespread rain and breezy conditions to the west coast and
the Bering, before potentially moving inland through the weekend.
&&
.SHORT TERM /THROUGH THURSDAY/...
An active pattern continues across northern AK through Tuesday,
although a short-lived ridge building in on Wednesday will diminish
rainfall chances to some extent. Satellite and radar imagery as of
the time of writing show a broad area of troughing stretching
along a SW to NE axis between St. Paul island and the northern
Yukon. The broad area of troughing is bringing with it a wide
variety of weather. Moderate to heavy rainfall across parts of
the central and western Interior will continue through Tuesday
morning, before chances of rain slowly diminish. Atmospheric
return Intervals of 5-10 years for some locations will be
reflected in precip totals of 2-3 inches for some of these
places before the current system winds down. Chances of rain are
also present across much of the North Slope and the eastern
interior, though rainfall totals for these areas will be
substantially lower as more isolated showers and thunderstorms
are expected. Along the West Coast, a marine layer will attempt
to push back in for some areas overnight into Tuesday, driven by
strong northerly flow through the Bering Strait.
CAPE values in the Yukon Flats and parts of the Brooks Range are
reaching model progged values of 400 to 600 J/KG through Monday
evening. This has fueled the development of isolated thunderstorms,
some of which look to have produced breezy conditions, plenty of
lightning, and periods of moderate to heavy rainfall.
The last big story has been the wind gusts across the eastern Alaska
Range. Chinook winds, driven by the presence of fairly respectable
pressure gradient of 5 to 7 mb across the Alaska Range, have
resulted in wind gusts as high as 70 mph for Isabel Pass, with other
locations seeing wind gusts approaching 60. Winds are currently on a
slow downward trend, and look set to continue that diminishing trend
through the evening and overnight hours into Tuesday.
Through the day on Tuesday, overall precip coverage and strength
will diminish as the trough weakens, though chances of thunderstorms
remain across parts of the eastern interior and the Brooks Range. On
Wednesday, a ridge briefly begins to build across the interior,
which will keep chances of drier weather for the east, even as an
old front keeps precip chances for the north slope, and a shortwave
brings chances of more widespread rain back in for Southwest Alaska.
&&
.LONG TERM /Thursday through Sunday/...On Thursday, weather
should lull briefly as weak troughing over Western Alaska will lead
to persistent, light showers in the Western Interior. Weak ridging
over Canada will lead to warmer and drier, but still moderate,
weather in the Central and Eastern Interior as maximum temperatures
should remain in the 60s. The North Slope will be cooler than the
Interior, but not as wet as Western Alaska.
More impactful weather arrives later in the week as another
widespread rain event is expected for the West Coast. The exact
timing is uncertain with this system, as deterministic models seem
to waver between the bulk of rain arriving overnight Thursday and
Friday afternoon. Ensemble models and clustering support the band of
rain arriving Friday morning, but it`s something we`ll want to keep
an eye on as the event gets closer. 48-hour rainfall totals for
Friday and Saturday along the West Coast currently range between
half an inch to an inch. Winds along along the coast will be strong
along with the rain. Gusts up to 40 mph through the Bering Strait
are possible on the rear side of the system. St Lawrence Island and
the YK Delta Coast are also prime candidates for strong wind gusts,
but remain slightly weaker for now. After the initial impact in
Western Alaska, rain, winds, and cooler temperatures will continue
east into the Interior, although to a lesser extent. Southerly gap
winds through the Alaska Range are expected to swell Saturday
morning before the concensus of models drop the low southeast into
the Gulf of Alaska.
Coastal Hazard Potential... No coastal hazards are expected through
the week.
&&
.FIRE WEATHER...
Warm and dry conditions with temperatures well into the 70s and RHs
below critical thresholds continue in the southeastern Interior;
southerly downsloping winds across the Alaska Range are drying out
the air considerably in these areas while also enhancing diurnal
warming. A Red Flag Warning has been issued for the Upper Tanana
Valley through 7 PM Monday evening for a combination of gusty
southerly winds, warm temperatures, and dry conditions. A fire
(Mukluk) has already developed in this area in the vicinity of Tok.
Through Isabel Pass and into the Delta Junction area, gusty winds,
potentially over 50 mph at times, will be possible through around
midnight tonight but are not likely to fully drop off until late
Tuesday morning. Elsewhere in the Central and Eastern Interior,
cooler conditions in the 50s and 60s with RHs above 40% prevail,
with isolated thunderstorms occurring and expected to continue near
the eastern border through this evening. In Western Alaska and parts
of the Central Interior, it is conversely very wet as a low moving
inland brings extensive rain and showers with wetting rains to the
area. The exception is from near Kotzebue northward, where
temperatures are above 70F in spots, although RHs are still over 40%.
By early Tuesday morning, rain (largely wetting) will overspread
most of the Middle Tanana Valley (including Fairbanks) and the Yukon
Flats, with highs dropping into the low 60s or upper 50s in most
areas. The exception will be the Upper Tanana Valley, which will
remain mostly dry. Some rain/showers and cooler conditions will also
take hold in the Northwestern Interior, ending the streak of warm
conditions there the past few days. By the late morning, southerly
flow across the Alaska Range will largely end, with moister RHs
favored in the Upper Tanana Valley than today. Temperatures are also
expected to drop to near or below 70F in these areas, although
minimum RHs could still fall into the 30s in some areas. By Tuesday
night, while numerous to widespread rainshowers could continue west
of Bettles/north of Tanana, they will become sparser and more
isolated in coverage elsewhere.
From Wednesday onward, temperatures could recover slightly in the
Eastern Interior, with most areas rising back into the mid to upper
60s, with temps around 70 possible in the Upper Tanana Valley, where
RHs in the 30s will be possible. Highs in the inland North Slope
will briefly fall into the 40s and 50s before recovering into the
60s on Thursday. By the late week, there is a signal for further
rain moving into Western Alaska and later the Interior with another
coastal low.
&&
.HYDROLOGY...
Some river rises are expected across the central interior and the
Brooks Range, as a stalled front delivers 5-10 year ARIs (2-3 inches
of rain) through Tuesday. However, previously low existing stream
conditions should prevent any flooding, although a few rivers could
reach bankfull. An ESF has been issued which discusses the river
rises in additional detail.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning until 7 PM AKDT this evening for AKZ936.
High Wind Warning until midnight AKDT tonight for AKZ849.
MARINE...Small Craft Advisory until 6 PM AKDT Tuesday for PKZ806-807.
Small Craft Advisory from 4 AM to 10 AM AKDT Tuesday for
PKZ808.
Small Craft Advisory until 1 AM AKDT Tuesday for PKZ810.
Small Craft Advisory until 7 PM AKDT this evening for PKZ811.
Small Craft Advisory from 10 PM this evening to 1 AM AKDT
Tuesday for PKZ817.
Small Craft Advisory from 10 PM this evening to 4 AM AKDT
Tuesday for PKZ853.
Small Craft Advisory until 10 AM AKDT Tuesday for PKZ854.
Small Craft Advisory until 1 PM AKDT Tuesday for PKZ856.
&&
$$
SHORT TERM...SPANN
SYNOPSIS...SPANN
LONG TERM...TROYKE
FIRE WEATHER...SALTZMAN
HYDROLOGY...SPANN/BEST
065
FXAK67 PAJK 172351
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
351 PM AKDT Mon Aug 17 2026
.SYNOPSIS...
Key Messages:
- A cold front will bring rain and gusty winds to the panhandle
before conditions gradually improve by early Tuesday.
- More seasonable conditions will prevail through the end of the
week with mostly cloudy skies and occasional showers as
multiple systems traverse the region.
&&
.SHORT TERM...Low pressure and an associated frontal system
continue to move east across the southeast Gulf. Southerly flow
has increased ahead of and along the system with frequent gusts
around 30 kts over the marine waters. Winds have also increased
over Lynn Canal and adjacent locales, including Skagway, where a
wind advisory continues this evening for gusts of 40-45 mph. The
most organized areas of rainfall have pushed into the central
panhandle, and points south to Prince of Wales Island. Additional
rainfall amounts will generally be a half inch or less as the
front weakens and much of the lift is lost. Precipitation will
further wane tonight and become more scattered. While winds will
remain elevated this evening, they will diminish rather quickly
after 06Z. This will also aid in the formation of some patchy fog
and low clouds toward daybreak.
By late Tuesday morning, weak high pressure will advance into the
eastern Gulf and southern panhandle. This will bring some breaks
in cloudiness and slightly warmer temperatures Tuesday afternoon
into Wednesday. Highs will average in the low to mid 60s for much
of the region, except the upper 60s to low 70s across the southern
panhandle.
Models have come into somewhat better agreement with the timing
of the next frontal system, with rain spreading into the northeast
Gulf Coast Wednesday evening and then into the northern and
central panhandle early Thursday. Subsequent waves of low pressure
will bring periodic rain showers late in the week as well. While
some of this activity will be locally moderate to heavy at times,
it is not expected to result in any significant hydrological
concerns given our antecedent dry conditions. In fact, this
rainfall is much needed, particularly in the southern panhandle,
although at this time it appears areas north of about Frederick
Sound will see the most sustained precipitation.
.LONG TERM.../Thursday through Sunday/...Active weather continues
into the long term period, especially over the northern panhandle.
To end the work week, an area of low pressure moves into the
northern gulf continuing to bring onshore flow, rain, and slightly
increased winds to the northern and central panhandle. An area of
high pressure southwest of the panhandle with a positively tilted
ridge axis will remain near Prince of Wales Island. This ridge will
likely keep the far south drier, but a few periods of light showers
may occur. That ridge, southwest of the area, breaks down Friday
into Saturday as a stronger low pushes into the northern gulf. There
is still some uncertainty on how strong this low will be. The
strength of the low will really help to indicate what weather
hazards to expect, like how much rain we may receive and how strong
winds may get. Confidence on the location and timing of this low has
slightly increased, but it is still a ways out.
Temperatures through the long term period remain near average with
high temperatures in the mid to high 60s. There are indications that
areas near Hyder will see temperatures into the mid to high 70s on
Thursday and Friday. The main indicators of this is continued dry
weather along with 850 temperatures between 12 to 15 C. The limiting
factor will be the amount of cloud cover that they receive as the
low pressure system moves into the gulf bringing more moisture into
the area.
&&
.AVIATION...Dreary flying conditions looking to continue through
the night, with widespread IFR to pockets of LIFR due to both
CIGs and VIS. Weaker than expected winds with lack of forcing
aloft looks to keep lower clouds and misty conditions in for
longer. As the front moves off, general onshore flow with mostly
MVFR CIGs and the occasional rain showers, mainly on west to
southwest facing mountains, will persist overnight.
Surface winds are on the downward trend this afternoon, with many
areas not expected to exceed 10 knots overnight tonight. The
exception continues to be Skagway, which may have gusts up to 40
knots for longer than expected.
&&
.MARINE...
Outer waters: Building high pressure in the gulf will contribute
to the downward trend in winds this evening, with winds maximizing
around a moderate breeze over open water. Waters near Cross Sound
are the exception here, with isallobaric winds (rising pressures)
increasing near this area, channeling into Cross Sound up to 20
knots. Similar story for wave heights, but with a predominantly
southwest swell up to 6 ft, wave are expected to be slow to
diminish. At the very least, waves will drop below small craft
criteria by tomorrow morning.
Inside waters: Few areas of note for the inside waters. The first
being the increased southwesterlies near the mouth of Glacier Bay
and Cross Sound from the aforementioned isallobaric winds. The
second being Clarence Strait, which is expected to be elevated for
longer with at least 20 knot winds through tomorrow evening. The
third and final being the persistent low clouds, mist, and fog
potential, primarily for the central panhandle.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Wind Advisory until 10 PM AKDT this evening for AKZ318.
MARINE...Small Craft Advisory for PKZ012-022-053-641>644-651-652-661>664-
671-672.
&&
$$
SHORT TERM...MJB
LONG TERM...EAB
AVIATION...NC
MARINE...NC
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