Flood in Alaska, June 22 to 30, 2025

Name: Flood in Alaska, June 22 to 30, 2025
Start: 2025-06-22T07:30
End: 2025-06-30T11:00
Location: Alaska

June 22 to 30, 2025 · NWS AFC · 1 event in 1 county or zone

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: $1.0 million
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS AFC wrote it up.

After a cool start to the month of June which slowed the melting of the mountain snowpack, Palmer quickly warmed up from June 10 through 21, 2025. In this timeframe, the Palmer airport reported six days of 70 F or above temperatures with a high of 75 F on June 19th. This reflects a warm and dry pattern that set up region-wide which enhanced snowmelt in the headwaters of the Matanuska River. Only 0.02 inches of rain fell at Palmer from June 10-21, but the warm weather caused rapid snowmelt and increased river flow as measured at the Matanuska River bridge (MATA2 Gage) in downtown Palmer during this period.

Weather throughout the region prior to the flooding of the Matanuska River featured a rapid change from cool and wet to warm and dry. Temperature measurements at the Palmer Airport indicate average temperature departures of up to 7.8 F below normal from June 1 to June 10 followed by a rapid increase in temperatures up to 4.8 degrees above normal from June 12 to June 21. Perhaps what is most notable, and the reason for rapid river rises along the Matanuska River, is the change in the alpine environment during this time period. For analysis, the Marmot Peak weather station located at 4,500 ft and the Independence Mine Snow Telemetry Site (SNOTEL) at 3,450 ft, both located in Hatcher Pass, will be used as proxy stations for the alpine and snow environment for the Matanuska River drainage. These stations are the only ones available in the region at representative elevations, and while neither of these stations directly influence the Matanuska River drainage, conditions were likely very similar.

Temperature data from the Marmot Peak weather station shows temperatures between June 1 and June 10 ranging from 26.1 F to 39.9 F with an average of 31.5 F. From June 11 to June 21, temperatures rose to between 35.6 F and 61.9 F with an average of 47.3 F. Analysis of the snow water equivalent shows little to no snow melt from June 1 to June 10 with multiple days of snow accumulation and a liquid equivalent increase up to 1 inch measured from June 6 to June 8. This was followed by a loss of 17.2 inches of liquid equivalent between June 10 and June 24. High resolution satellite imagery captured by the Sentinel-2 polar orbiting satellite shows a rapid reduction in high-elevation snowpack surrounding the greater Palmer area and Lower Matanuska Valley. Similar satellite imagery shows an altered river state from June 12 to June 20.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Anchorage, AK wrote its last area forecast discussion before the first event at Jun 22, 4:18 AM AKST, 3 hours 12 minutes earlier.

Area forecast discussion, Jun 22, 4:18 AM AKST, 3 hours 12 minutes before

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
518 AM AKDT Sun Jun 22 2025

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

Discussion:

A front lifting north across the Gulf today will bring increased
chances for scattered rain showers to portions of Southcentral today
and tomorrow. Cloud cover has already increased ahead of this front
and light radar returns were noted over the Barren Islands moving
north towards the southern Kenai Peninsula. As the front lifts north
across the Kenai later this morning and early afternoon, showers
will begin to spread up the Cook Inlet towards the Anchorage Bowl
and Mat-Su. Models are in good agreement with the mid-level front
stalling over Prince William Sound westwards into the Susitna Valley
by early Monday morning. A secondary wave will lift in behind this
front as the parent low over the central Bering pivots eastwards to
the Bristol Bay/AKPEN region. Increasing lift over the stalled front
will result in rain showers becoming more widespread with a modest
precipitation band setting up from the Susitna Valley over to the
northern Gulf coast. The band will slowly lift north Monday becoming
more scattered as lift decreases over the region.

Temperatures will cool a bit over the next several days with the
increase in cloud cover and showery conditions. Thunderstorm
potential will shift north of the Wrangells towards the eastern
Alaska Range and the interior where the instability axis will set-
up. The Copper Basin will see warm temperatures again today with a
period of breezy winds for the southern Basin, but increasing
moisture will keep fire weather concerns in check today. Scattered
showers and cooler temperatures will also move into the Copper Basin
Monday with additional showers expected Tuesday. Mid and long range
models have this more unsettled weather pattern persisting through
much of the upcoming workweek.

- PP

&&

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

The large upper-level low that has sat around the Central
Aleutians the last couple of days has elongated and moved towards
the Pribilof Islands this morning. A complex surface low with
centers to the west of the Pribilofs and just north of the Central
Aleutians will continue drift and rotate around each other
through today. Expect showery and misty conditions to continue
today and into Monday across the Eastern Aleutians, Pribilofs, and
southern Alaska Peninsula (AKPEN). Gusty southeast winds across
the southern AKPEN, especially through Cold Bay, will slowly
diminish starting this evening.

The next big weather-maker for the Aleutians and Bering Sea will
come in the form of a front and low moving eastward from
Kamchatka. The gale-force front moves into the Western Aleutians
and western Bering Sea this evening. The front weakens to high-end
small-craft by Monday morning as it reaches the Central
Aleutians. The front then weakens further as it makes it to the
Eastern Aleutians and Pribilof Islands Monday evening and the
southern AKPEN on Tuesday. The heaviest rain will be confined to
Western and Central Aleutians with light rain elsewhere across the
Bering and Chain. Warm air will advect across the Western and
Central Aleutians behind this front from west to east starting
Monday. This will bring the chance for some fog and mist to
develop after the steady rain ends. Gusty westerly winds up to
gale-force will also persist across the southwestern to
southcentral Bering with the low moving into the northwest Bering
late Monday into Tuesday and high pressure remaining to south in
the North Pacific. Shower chances remain across the Bering,
Aleutian Chain, Pribilofs, and southern AKPEN for Wednesday as the
low moves into the central Bering by then.

Meanwhile, scattered showers will continue along the mainland
southwest coast today, with perhaps isolated showers developing
inland. Most of mainland Southwest Alaska remains on the cooler
and cloudy side with temperatures in the interior only getting
into the low to mid-60s and coast remaining in the 50s. Greater
shower chances arrive for Monday and Tuesday in the interior,
especially along the Western Alaska Range, when the 500 mb trough
axis in the eastern Bering/Bristol Bay begins to become negatively
tilted and slowly lifts northward through the area. Right now, the
chance for lightning strikes in the interior with the upcoming
showery activity for Monday and Tuesday is low due to increased
cloud cover and the best day-time heating and instability being
north and in the Yukon Valley. For Wednesday, the Bering front
that will bring rain and gusty winds across the Aleutian Chain
over the next couple of days will make it to the mainland
Southwest coast. The front will be in a weakened state by this
time, but will still deliver southeast winds along the Kuskokwim
Bay and Bristol Bay coasts. Most rain will remain along the coast
with the potential for some scattered showers inland.

&&

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

Beginning to get a little more motion in the weather systems
across the Alaska region through the forecast period. A closed
upper level low over the Central Bering begins its trek across the
Alaska Peninsula into the Gulf of Alaska by the weekend. Several
shortwaves rotating through the pattern help accelerate its
movement, and help set up some Easterly wave conditions across
Southcentral Alaska. The upper level ridge across the Northern
portions of Mainland Alaska drift into the Arctic through
Saturday. Forecast guidance begins with a deterministic blend of
GFS / ECMWF and Canadian models that diverge early in the period,
so a change to ensemble means will carry the large scale features
through the rest of the forecasts.

Diminishing warmer temperatures over Interior Alaska helps draw
down the possibilities of convective activity across the Central
Alaska, with the last of the showers and thunderstorms occurring
in the Eastern border zones. A slowly weakening surface low near
the Pribilofs slips across the AKPEN into the Central Gulf of
Alaska by the weekend. Windy conditions close to gale force slips
over the Western and Central Aleutians for Wednesday. Gusty winds
cross the Central Aleutians late Thursday into early Friday.
Widespread rain over the Eastern Bering moves over Southwest
Alaska, AKPEN and Kodiak Island through Friday and spread along
the Southcentral coast through Saturday. Gusty Easterly winds set
up over the Northern Gulf of Alaska late Friday into Saturday. A
moderately strong North Pacific low approaches the Western
Aleutians with rain for Friday before heading back into the North
Pacific for Saturday.

- Kutz

&&

.AVIATION...

PANC...VFR conditions will persist through this afternoon.
Ceilings will begin to lower and chances for scattered showers
will increase tonight. There may be periods where ceilings drop to
MVFR, especially by Monday morning as precipitation chances
increase. Winds are expected to remain southwesterly today
becoming light and variable overnight.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flood. Local standard time, as filed.

Flood, Matanuska Valley

When: June 22, 7:30 AM AKST to June 30, 11:00 AM AKST
Where: Matanuska Valley County, 6.32 mi WSW of Sutton to 5.81 mi SSE of Palmer
Cause: Heavy Rain / Snow Melt
Property damage: $1.0 million
Reported by: Department of Highways
Coordinates: 61.686, -149.079

After a cool start to the month of June, Palmer quickly warmed up June 10 through 21, 2025. In this timeframe, the Palmer airport reported six days of 70 or above temperatures with a high of 75 on June 19th. This reflects a warm and dry pattern that set up region-wide and enhanced snowmelt in the headwaters of the Matanuska River. Further, only .02 inches of rain fell at Palmer from June 10-21. Warm temperatures and bank erosion led to high water breaking through the banks of the Matanuska River (noted at the Matanuska River Bridge (MATA2) gage) between the Old Glenn Highway and the River in the Maud Road area due to flooding caused by snowmelt and a river channel shift.

Reports indicate that due to this flooding, five homes and two businesses were damaged, and $1 million plus in road damage was noted. This led to a local disaster declaration.

News articles:|https://www.alaskasnewssource.com/2025/06/23/matanuska-river-flooding-crew-works-emergency-protective-measures/. |https://www.alaskasnewssource.com/2025/06/25/matanuska-river-flooding-leaves-river-running-through-properties/.

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Alaska in 2025 Every state in 2025 This day in weather history Warnings in Alaska, June 2025

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1272020.