Graphical Hydro Meteorological Discussion

892
FXAK68 PAFC 130041
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
441 PM AKDT Tue May 12 2026

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

Winds across the northern Gulf and along the coast continue to
slowly weaken this afternoon as the front progresses north and
inland. Moderate, steady rain is expected to continue through
tonight for western Prince William Sound, while precipitation
becomes more scattered along the eastern Kenai Peninsula as the
evening progresses. Another round of gusty gap winds out of the
typical spots across the Kenai Peninsula and Chugach Mountains are
expected through this afternoon before the coastal ridge fully
weakens with the frontal progression.

As the front lifts inland and dissipates through Wednesday
morning, the weakening parent low pivots across the Alaska
Peninsula into the western Gulf. This will mark the end of the
steady coastal rain which will give way to more showery conditions
as multiple weak shortwaves rotate northwest into Southcentral.
Shower activity over inland areas will likely increase as well on
Wednesday as the strong southeasterly, cross-barrier flow
relaxes. Similar conditions with widely scattered showers and weak
easterly flow will persist into Friday.

&&


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

A complex low sits over the central Bering this morning with
several areas of low pressure rotating around its periphery. Gusty
northwesterly winds over Adak and nearby islands will diminish
overnight as a wave pushes through. Precipitation has eased across
most of the region, but not come to an end yet. By Wednesday
morning, rain showers will temporarily reinvigorate over the
eastern Aleutians, including Unalaska, Nikolski, and Akutan,
coming to an end by Thursday morning. Into Wednesday the complex
low over the Bering will begin to shift over the Alaska Peninsula
as the area of low pressure, tracks eastward and south of the
Aleutian Chain toward Kodiak Island. For Southwest Alaska, a
showery regime will continue through the latter half of the week
while southeasterly flow downstream of the complex low continues
within an unsettled pattern. The next major storm system will come
into the picture on Thursday. A North Pacific low and front are
set to track just south of the Aleutian Chain, but the front
itself may move over Adak and Atka with potential gales and heavy
showers.

-BL/CL

&&


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

Troughing over the eastern Bering looks to persist through early
next week and favor an unsettled pattern, especially for coastal
areas of southcentral Alaska. By Saturday morning, low pressure
will be situated over the eastern portions of the Aleutian Chain.
A front from this low enters the southwestern Gulf Saturday and
stalls in the northern Gulf Sunday. With a coastal ridge in place,
strong easterly to east-southeasterly winds are expected in the
Gulf as the front moves through. Peak winds look to be Saturday
afternoon through Sunday along the northern Gulf coast and
through the Barren Islands and Kamishak Gap. Additionally, chances
for precipitation this weekend are high along the northern Gulf
coast, Kodiak Island and eastern AKPen with upsloping winds. The
heaviest precipitation looks to be Saturday for Kodiak Island and
the eastern AKPen and Saturday night through Sunday for the
northern Gulf Coast. There are still some slight timing
differences with the progression of this front, details which will
be resolved in the coming days. Outside of the coast, most of
interior southcentral looks to be dry. Some light precipitation
may spill over the Kenai Mountains and Chugach Front Range on
Sunday. The main low looks to stall over the eastern Bering this
weekend and slowly occlude. This will maintain chances for
precipitation through the AKPen and Bristol Bay coast over the
weekend into early next week.

After Sunday night model agreement wanes. Ensembles maintain
troughing over the Bering with a potential ridge building over
western Canada starting Monday. Should this hold, general
southwest flow serves as a favorable track for additional lows to
move from the Aleutian Chain through southcentral Alaska. Only
some models currently hint at additional lows forming early next
week, hence high uncertainty. Nonetheless, the pattern early next
week will maintain favorable chances for precipitation for
southern Alaska, especially for coastal southcentral and areas
with upsloping winds.

PA

&&


.AVIATION...

PANC...VFR cigs and vis will continue. Models are trending towards
the development of a light southeasterly/Turnagain Arm wind this
evening, so have reflected that in the forecast beginning 03z.
There is still a chance of winds remaining northerly to
northwesterly instead - if that is the case, expect directional
wind shear to persist through late evening as winds will be
southeasterly aloft. Confidence is much greater for gusty winds
out of Turnagain Arm tomorrow afternoon.

&&


$$

549
FXAK69 PAFG 122247
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
247 PM AKDT Tue May 12 2026

.SYNOPSIS...
Spring will be in full swing south of the Brooks Range for the
next several days as temps climb into above normal territory.
Meanwhile winter will still be hanging on across the North Slope.
The next few days will see strong east winds and some blowing snow
near the Arctic coast while elsehwere mainly dry conditions are
expected. There will be the occasional shower at times throughout
central portions of the state as some energy spins north from a
series of storms that will move through the Aleutians and into
the southern Bering Sea, but widespread stormy weather will be on
hold for a while.

&&

.KEY WEATHER MESSAGES...

Central and Eastern Interior...

- Easterly winds up of 15 to 25 mph will be possible over higher
terrain of the Central and Northeastern Interior, and could
last into later this week before weakening.

- Much warmer temperatures are expected the next few days, with
highs today rising into the low to mid 60s in the Middle and
Upper Tanana Valleys today, with upper 60s possible across the
far eastern Interior.

- Mainly dry for the next couple of days, however some scattered
showers will be possible near the Alaska Range slopes and across
the Upper Tanana Valley Wednesday and Thursday.

West Coast and Western Interior...

- A few light showers will be possible through Wednesday across
the YK Delta and the Norton Sound.

- Scattered thunderstorms will be possible from the Upper
Kuskokwim Valley into parts of the Western Interior Wednesday
afternoon.

- Gusty north winds of 25 to 35 mph will be possible Wednesday
along the western Seward Penn and throughout the Bering Strait.

- Warming temperatures are expected the next few days, with highs
will rising into the mid to upper 50s across the Western
Interior and the Interior Seward Peninsula.

North Slope and Brooks Range...

- Gusty winds will continue across the North Slope today. Winds
will be strongest along the Western and Eastern Arctic Coast
where winds could peak upwards of 40 mph.

- Winds will remain elevated along the coast through at least
Wednesday before gradually ending from west to east through the
Friday. These winds will lead to areas of blowing snow which
could reduce visibility at times.

&&

.FORECAST ANALYSIS AND DISCUSSION...
Clearing skies overnight led to a rather chilly start to this
Tuesday as temps fell into the upper 20`s to near 30 for parts of
the Tanana Valley. However temps should be making a big recovery
for most areas over the next few days. An extensive upper ridge
stretching from the southwestern US into western Canada will
continue to build over eastern and northern Alaska through Friday.
Meanwhile, troughing and an associated surface low over the
Bering Sea will be working it`s way eastward and undercut the
ridge the next few days. In general this pattern will be favorable
for the Interior as temps get a nice boost while most of the
heavy precipitation and strong winds associated with the low
remains south of the Alaska Range.

The exception will be across the North Slope and Arctic Coastline
where temps will stay on the colder side thanks to a strong
Arctic high lingering across the southern Beaufort Sea. This will
continue to funnel a brisk easterly surface flow along the Arctic
coastline the next couple of days. As winds increase to between 30
and 40 mph in spots, especially the eastern Arctic coastline,
some blowing snow and reduced visibilities will occur. In addition
the same gradient between the Arctic High and the low in the
Bering will keep breezy conditions ongoing across the central
Brooks Range and the higher terrain of the Central Interior as
well.

As for precipitation chances, the low in the Bering will likely
send shortwave energy north and westwards tonight and Wednesday.
Initially some light precipitation will traverse the YK Delta and
Norton Sound area tonight. Meanwhile additional precipitation
should develop over the Upper Kuskokwim and Western Interior
Wednesday afternoon. Hi-res model soundings for Wednesday
afternoon over the upper Kuskokwim show modest CAPE values
developing in the afternoon and K index values of around 25 which
indicates an increasing probability that at least some
thunderstorms may develop.

&&

.FIRE WEATHER...
Today, the main concern will be across western Alaska and areas near
the YK Delta where the tight pressure gradient between the Bering
Sea low and Arctic high produces strong southeasterly/easterly winds
and enhanced boundary-layer mixing. Despite generally dry
conditions, cooler temperatures and limited instability should help
prevent more critical fire weather conditions. As the low shifts
east into the Gulf Wednesday and Thursday, the pressure gradient
weakens and winds diminish substantially across the Interior,
reducing large-scale wind-driven fire spread potential. Behind the
departing trough, colder air aloft combined with increasing solar
heating will support scattered afternoon convective showers, mainly
across the western and eastern Interior. There is a chance for
isolated lightning strikes Wednesday afternoon and evening across
the eastern YK Delta where instability appears to be marginally
stronger, though thunderstorm coverage is expected to remain sparse.
Most showers should remain primarily rain-producing with limited
vertical development, reducing the threat of dry lightning and
widespread holdover concerns. Even so, the convective nature of the
showers could still produce localized gusty outflow winds near
heavier cells despite otherwise light ambient winds. By Friday,
another Bering Sea low begins tightening the gradient once again
across western Alaska, leading to a slight increase in winds near
the YK Delta while scattered convective showers continue across
portions of the Interior. Overall fire risk remains low across most
of the region with main threats in areas of stronger winds
associated with passing of the lows as well as localized gusty
outflow winds near convective showers.

&&

.HYDROLOGY...

Koyukuk River:
A Flood Warning is in effect for the Koyukuk River at Hughes for
ice jam flooding. Members of the public and emergency manager
reported continued flooding in low lying areas, including
significant impacts to the airport and school property.

Yukon River:
The Yukon River breakup front has moved well downstream of Tanana
with bank to bank ice runs extending back to near Tanana.
Downstream of the breakup front large ridges and shifting ice
sheets were noted From Ruby to Galena with open water in place
downstream of this area of ice.

Chena River:
The Chena River has begun to respond to warmer temperatures with
increased snowmelt leading to rivers running higher and gages
getting closer or reaching action stage.

Salcha River:
The Salcha River is expected to reach action stage later this
week as warmer temperatures lead to increased snowmelt.

ADDITIONAL INFORMATION

Head to www.weather.gov/aprfc for the latest hydro information.

Please report observed flooding to local emergency services, law
enforcement, or to the National Weather Service when you can do so
safely.

&&

.EXTENDED FORECAST DAYS 4-7... (Saturday through Tuesday)
The extended period will be dominated by an upper ridge extending
north from western Canada into eastern and northern Alaska while
a persistent upper trough stays in place over the Bering Sea and
far north Pacific. Beginning Saturday a low over the central
Aleutians will send shortwave energy north resulting in some
shower activity from the YK Delta up into the western Interior
while strong gap winds could again develop through the Alaska
Range passes. This may bring about additional fire weather
concerns for the middle and upper Yukon Valley over the weekend.
A second low will swing into the southeast Bering late in the
period which will again send shortwave energy north into Alaska`s
Interior with additional chances for scattered showers and even a
few thunderstorms. Meanwhile high pressure will dominate the North
Slope through the extended period. Breezy conditions will be
likely along the Arctic coastline while temps slowly begin to
moderate.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801-850.
Small Craft Advisory for PKZ804.
Brisk Wind Advisory for PKZ809.
Heavy Freezing Spray Warning for PKZ812.
Brisk Wind Advisory for PKZ813.
Brisk Wind Advisory for PKZ814-815.
Small Craft Advisory for PKZ817.
Brisk Wind Advisory for PKZ851.
Small Craft Advisory for PKZ854.
Brisk Wind Advisory for PKZ860.
Brisk Wind Advisory for PKZ861.
&&

$$

Laney/Cruz-Fire WX

799
FXAK67 PAJK 122342
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
342 PM AKDT Tue May 12 2026

.SYNOPSIS...

Key Messages:

-Warmer and drier conditions to start the week before more light
rain moves in and spreads throughout the panhandle midweek.

-Winds and seas increase out in the Gulf and along the N Gulf
coast Monday night into Tuesday as the next front pushes into the
region.

&&

.SHORT TERM...Forecast in the short term remains largely
unchanged ahead of the front moving in overnight tonight and
Wednesday. Clear skies across much of the panhandle today have
brought warmer temperatures and some sea breezes that will last
into the evening today. The exception of these clearer skies this
evening is some cloud cover and shower activity over the far
southern part of the panhandle which is expected to travel a bit
northward, to around Petersburg and Frederick Sound, later
tonight. The weak front currently over the central Gulf will begin
to bring some cloud cover back over the area into tonight, with
precipitation along the coastline beginning in the overnight
hours. This front will continue to move northeastward through
Wednesday, with light precipitation still expected and rainfall
totals in 24 hours remaining under 0.5 inches.

The front will be followed by showers as the weak low lingers in
the western Gulf, with another more disorganized round of
precipitation enabled by a shortwave rotating through Wednesday
night into Thursday. Precipitation chances across the northern
panhandle will begin to gradually diminish during the day through
Thursday night. Temperatures both days will remain more close to
normal for this time of year, cooling after today`s warmer
conditions from the cloud cover associated with the front and
lasting onshore flow.

.LONG TERM.../Thursday through Sunday/...

Through Thursday, a low lingers in the western Gulf of Alaska,
weakening as it attempts to traverse east. onshore flow will
continue to bring less organized rounds of precipitation into the
panhandle. These showers will follow behind the front and last
through the day Thursday as shortwaves rotate around the low
aloft. The surface and upper level troughing will begin to dig
southeastward near the coast of B.C. as some ridging develops over
the Aleutians and north Pacific along with the high pressure
building over the panhandle, keeping much of the shower activity
more southward with more of a break in weather for the northern
half of the panhandle Friday. The next system will begin to move
in from the west Saturday night, bringing another front through
the area into Sunday.

&&

.AVIATION...
A ridge of high pressure remains centered over the Central Alaska
Panhandle leading to mostly VFR conditions across the area.
Yakutat has been experiencing MVFR conditions due to low-level
moisture ahead of the front. Under high pressure, sea breeze flow
has developed for Lynn Canal, Gustavus, and Juneau. Otherwise,
winds look fairly weak due to the high pressure over the area.
Similar to Tuesday morning, there may be some fog developing
Wednesday morning around Petersburg.

Wednesday morning, a front moving from Southwest to Northeast will
bring lower ceilings and rainfall across the area. It is forecast to
impact Yakutat first, and eventually eastward through the rest of
the Panhandle. The front is expected to move out of SE AK after the
TAF period ends.

&&

.MARINE...
Inner Channels: With high pressure anchored over the panhandle into
Tuesday evening, clearer skies have allowed some sea breezes to
develop in communities of the northern and central panhandle.
Winds are still expected to stay 20 kt or less with the highest
winds occurring later on Wednesday as a weakening front moves over
the area. Seas likewise will be generally low with 4 ft of less
wind driven waves in most areas. Again the highest seas will be on
Wednesday near ocean entrances as the front moving through.

Gulf waters: E and SE winds of 25 kt or greater are mainly found
from 140 W longitude and westward in association with that front
that stretches N to S across the central gulf. Highest winds are
near Cape Suckling at around 25 to 30 kt as of this discussion.
These winds are expected to peak this afternoon before gradually
diminishing Tuesday night and through Wednesday as the front
deteriorates and pushes inland. Wind greater than 20 kt are still
expected to stay west of 140 W with mainly 20 kt winds E of that
Tuesday night as the front moves through. Behind the front winds
diminish and turn more SW and S into Wednesday night. Still expected
max wave heights of around 8 to 9 ft mainly near Cape Suckling
through Tuesday night before diminishing winds allow wave heights to
start subsiding again down to around 6 ft for Wednesday and
Thursday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ652-671-672.

&&

$$

SHORT TERM...Contino
LONG TERM...Contino/GFS
AVIATION...Musall
MARINE...STJ

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