Alaska, 2023

Flooding in Alaska, May 12 to 15, 2023

May 12 to 15, 2023 · NWS AFG · 3 events in 2 counties and zones

A prolonged period of well-below-average spring temperatures combined with an above-average winter snowpack created a dynamic breakup of the Yukon River. This resulted in numerous ice jams and snowmelt flooding on the Yukon River.

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
None recorded
Crop damage
None recorded
Events
3

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 AFG wrote it up.

A prolonged period of well-below-average spring temperatures combined with an above-average winter snowpack created a dynamic breakup of the Yukon River. This resulted in numerous ice jams and snowmelt flooding on the Yukon River. Breakup flooding began on May 12th in eastern Alaska in Eagle and ended on June 3rd in the Yukon River delta at the Bering Sea coast at the community of Emmonak. The primary cause of this active flood year was a 1-2 week delay in breakup when compared to typical timing. April temperatures were well below normal, and when temperatures began to warm in early May, it melted the low-elevation snowpack quickly. Because of the relatively quick addition of snowmelt onto strong ice, the ice was more susceptible to jamming and floods. In addition to the late breakup, the snowpack this winter was 1 to 1.5 times greater than the climatological normal for interior and western Alaska. Significant ice jams and associated flooding on the Yukon River in Canada resulted in large volumes of ice and water to move down the Yukon River into Alaska.

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 Fairbanks, AK wrote its last area forecast discussion before the first event at May 12, 1:48 PM AKST, 3 hours 49 minutes earlier.

Area forecast discussion, May 12, 1:48 PM AKST, 3 hours 49 minutes before
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
248 PM AKDT Fri May 12 2023

.SYNOPSIS...
Busy weather pattern over Northern Alaska with ongoing Flood
Watches for Ice Jam Flooding potential near Eagle and near Manley
Hot Springs, Wind Advisories for the Alaska Range and near Delta
Junction for Saturday afternoon into Monday morning and near Red
Flag conditions for the northern foothills of the Alaska Range and
near Delta Junction for Sunday. A strong storm will be impacting
the West Coast with strong winds, heavy rain and potential for
rapid snowmelt over the weekend and into early next week. There is
also the potential for minor ice shoves along the northern coast
of Norton Sound between Nome and Golovin over the weekend.

&&

.DISCUSSION...

Upper Levels and Analysis...
A strong shortwave over the Central Bering Sea will continue to
push east over the West Coast and Western Interior and then push
north over the Western North Slope on Saturday as a ridge builds
over the Central and Eastern Interior and the Yukon. A second
strong shortwave over the Eastern Bering Sea on Sunday night will
dive south and east into the Northwest Gulf of Alaska on Monday.

On the surface a 992 mb low with a strong front trailing to the
south will continue to push north and east and will be located
near the Bering Strait as a 988 mb low by Saturday afternoon with
the trailing front just west of the Coast. High pressure will
remain and build over the Eastern interior and the Yukon into
Sunday. The low over the Bering Strait on Saturday will slowly
move north and east into the Chukchi Sea as the trailing front
stalls over the West Coast and Western Interior on Sunday. Waves
of moisture will train north along the front bringing heavy rain
and high elevation snow to the Western Brooks Range and heavy
rain southward into the YK Delta. South facing slopes of the
Brooks Range, the Seward Peninsula and the Nulato hills are
expected to receive up to 2 inches of rain through Monday morning.
This heavy rain combined with heavy snowpack will cause water
levels to rise and possibly begin the breakup process on many
rivers along the West Coast and in the Western Interior. The
potential exists for local ice jams to form and result in elevated
water levels. The increased runoff may also cause smaller streams
and creeks to rise to bankfull levels or overbank in low lying
areas.

A strong pressure gradient through the Alaska Range combined with
upper level southerly winds will produce strong winds through the
Alaska Range where Wind Advisories have been issued. The strong
winds and low relative humidity levels will produce near Red Flag
Conditions along the norther foothills of the Alaska Range
northward to near Delta Junction on Sunday. Winds will be strong
in these areas on Saturday, however minimum relative humidity
levels are expected to remain above 30 percent.

Central and Eastern Interior...
A warming trend to near or just above normal temperatures is
expected across Interior and Northern Alaska through the weekend
and into early next week. Scattered to numerous showers possible
over the eastern Interior tonight and into Saturday morning. High
temps pushing into the mid 60s on Friday and into the weekend.
Strong winds will develop over the northern foothills of the
Alaska Range and through the passes and northward to near Delta
Junction and Healy on Saturday afternoon and will continue to into
Monday morning. Relative humidity levels will drop to around 35
percent on Saturday but will drop to near 25 percent with near Red
Flag Conditions developing on Sunday in these areas.

West Coast and Western Interior...A strong front moving east out
of the Bering Sea will stall over the area this weekend and into
early next week. This front is expected to bring strong southerly
winds and heavy rain to the West Coast and Western Interior. The
heavy rain combined with an above normal snowpack over higher
elevations, will cause a significant increase in snowmelt. Runoff
into rivers along the south faces of the Brooks Range southward to
the Lower YK Delta over the weekend and early next week will
cause water levels to rise and possibly begin the breakup process
on many rivers. The potential exists for local ice jams to form
and result in elevated water levels. The increased runoff may also
cause smaller streams and creeks to rise to bankfull levels or
overbank in low lying areas. This front is expected to bring
strong southerly winds and the potential for minor ice shoves
along the Northern Coast of Norton Sound over the weekend.

North Slope and Brooks Range...
Low stratus and periods of dense fog will continue to plague the
Arctic coast through Saturday. Winds will ramp up from the south
Saturday night into Sunday as a strong front moves into the west
coast. Gusty winds expected in the Brooks range. Temps will also
warm up to the upper 30s and lower 40s by Sunday.

Coastal Hazard Potential Days 3 and 4...None.

&&

.FIRE WEATHER...
Near Red Flag conditions to develop on Sunday near the Alaska
Range and Delta Junction. Strong winds will develop through the
Alaska Range Passes and northern foothills Saturday afternoon and
will continue into Monday morning with sustained winds of 25 mph
and with gusts to 50 mph expected near Delta Junction and winds of
35 to 45 mph with wind gusts to near 60 mph expected near the
Alaska Range. Minimum relative humidity levels are expected are
expected to drop to around 35 percent on Saturday and will likely
drop to around 25 percent on Sunday and will produce near Red Flag
conditions in these areas on Sunday. Low relative humidities in
the mid 20s will extend north into the middle Tanana Valley
however temperature and wind criteria are not expected to be
exceeded.

&&

.HYDROLOGY...
Flood watches for ice jam flooding remain in effect for the Eagle
area as well as the Manley Hot Springs area.

A strong front moving east out of the Bering Sea will stall over
the area this weekend and into early next week. This front is
expected to bring strong southerly winds and heavy rain to the
West Coast and Western Interior. The heavy rain combined with an
above normal snowpack over higher elevations, will cause a
significant increase in snowmelt. Runoff into rivers along the
south faces of the Brooks Range southward to the Lower YK Delta
over the weekend and early next week will cause water levels to
rise and possibly begin the breakup process on many rivers. The
potential exists for local ice jams to form and result in elevated
water levels. The increased runoff may also cause smaller streams
and creeks to rise to bankfull levels or overbank in low lying
areas.

This front is expected to bring strong southerly winds and the
potential for minor ice shoves along the Northern Coast of Norton
Sound over the weekend.

People along rivers and streams along the West Coast and in the
Western Interior should prepare for the possibility of high water
levels this weekend and next week due to ice breakup and snowmelt
runoff.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...High Wind Warning for AKZ213-214.
     Flood Watch for AKZ221.
     Wind Advisory for AKZ223-226.
     Flood Watch for AKZ224.
     Wind Advisory for AKZ225.
PK...Small Craft Advisory for PKZ801-802.
     Brisk Wind Advisory for PKZ803-810-852.
     Small Craft Advisory for PKZ804>806-817.
     Gale Warning for PKZ816-850.
     Gale Warning for PKZ851.
     Brisk Wind Advisory for PKZ853.
     Brisk Wind Advisory for PKZ854.
&&

In the hours before

Special weather statement, May 12, 1:10 PM AKST, 4 hours 27 minutes before
Special Weather Statement
National Weather Service Fairbanks AK
210 PM AKDT Fri May 12 2023

AKZ207>210-212>217-227-132000-
Chukchi Sea Coast-Lower Kobuk and Noatak Valleys-
Baldwin Peninsula and Selawik Valley-
Northern and Interior Seward Peninsula-
Eastern Norton Sound and Nulato Hills-
St Lawrence Island and Bering Strait Coast-Yukon Delta-
Lower Yukon Valley-Lower Koyukuk and Middle Yukon Valleys-
Upper Kobuk and Noatak Valleys-Upper Kuskokwim Valley-
Including Point Hope, Shishmaref, Kivalina, Espenberg, Noatak,
Kiana, Red Dog Mine, Kotzebue, Selawik, Noorvik, Buckland,
Deering, Candle, Council, Haycock, Pilgrim Springs,
Serpentine Hot Springs, Taylor, Unalakleet, Stebbins, St Michael,
Elim, Koyuk, Shaktoolik, Gambell, Savoonga, Brevig Mission,
Teller, Wales, Diomede, Mountain Village, Emmonak, Alakanuk,
Kotlik, Pilot Station, St Marys, Scammon Bay, Hooper Bay,
Marshall, Nunam Iqua, Pitkas Point, Russian Mission, Grayling,
Holy Cross, Shageluk, Anvik, Flat, Galena, Nulato, Huslia,
Kaltag, Ruby, Koyukuk, Ambler, Shungnak, Kobuk, McGrath, Nikolai,
Takotna, and Farewell Lake
210 PM AKDT Fri May 12 2023

...High Water Levels Possible This Weekend and Next Week...

A strong front moving east out of the Bering Sea will stall over
the area this weekend and into early next week. This front is
expected to bring strong southerly winds and heavy rain to the
West Coast and Western Interior. The heavy rain combined with an
above normal snowpack over higher elevations, will cause a
significant increase in snowmelt. Runoff into rivers along the
south faces of the Brooks Range southward to the Lower YK Delta
over the weekend and early next week will cause water levels to
rise and possibly begin the breakup process on many rivers. The
potential exists for local ice jams to form and result in elevated
water levels. The increased runoff may also cause smaller streams
and creeks to rise to bankfull levels or overbank in low lying
areas.

People along rivers and streams along the West Coast and in the
Western Interior should prepare for the possibility of high water
levels this weekend and next week due to ice breakup and snowmelt
runoff.

The latest breakup information is available at
www.weather.gov/aprfc/breakupMap.

AKZ211-132000-
Southern Seward Peninsula Coast-
Including Nome, White Mountain, and Golovin
210 PM AKDT Fri May 12 2023

...Minor Ice Shoves Strong winds and Heavy Rain Possible This
Weekend and Next Week...

A strong front moving east out of the Bering Sea will stall over
the area this weekend and into early next week. This front is
expected to bring strong southerly winds and the potential for
minor ice shoves along the Northern Coast of Norton Sound over the
weekend. In addition, heavy rain is expected especially along the
south facing slopes of the Seward Peninsula through the weekend
and into early next week. The heavy rain combined with an above
normal snowpack over higher elevations, will cause a significant
increase in snowmelt. Runoff into rivers along the south facing
slopes of the Seward Peninsula over the weekend and early next
week will cause water levels to rise and the potential to start
the breakup process on many rivers. Local ice jam may form and
result in elevated water levels. The increased runoff may also
cause smaller streams and creeks to rise to bankfull levels or
overbank in low lying areas.

People along rivers and streams along the West Coast should
prepare for the possibility of high water levels this week and
next week due to potential ice breakup and snowmelt runoff. People
along the Northern Coast of the Seward Peninsula should be
prepared for minor ice shoves this weekend.
Special weather statement, May 12, 1:14 PM AKST, 4 hours 23 minutes before
Special Weather Statement
National Weather Service Fairbanks AK
214 PM AKDT Fri May 12 2023

AKZ218>226-140000-
Southeastern Brooks Range-Upper Koyukuk Valley-
Yukon Flats and Surrounding Uplands-Central Interior-
Middle Tanana Valley-Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-Denali-
Eastern Alaska Range-
Including Arctic Village, Wiseman, Coldfoot, Chandalar DOT Camp,
Iniakuk Lake, Allakaket, Hughes, Bettles, Caribou Mountain,
Gobblers Knob, Fort Yukon, Venetie, Central, Circle,
Stevens Village, Beaver, Chalkyitsik, Birch Creek,
Circle Hot Springs, Eagle Summit, Twelvemile Summit, Nenana,
Anderson, Tanana, Minto, Manley Hot Springs, Rampart,
Lake Minchumina, Livengood, Fairbanks, Fort Wainwright,
Eielson AFB, Ester, North Pole, Moose Creek, Two Rivers, Fox,
Chatanika, Chena Hot Springs, Sourdough Camp, Salcha,
Delta Junction, Fort Greely, Harding/Birch Lake, Dry Creek,
Dot Lake, Healy Lake, Tok, Tanacross, Eagle, Tetlin, Northway,
Alcan, Chicken, Boundary, Healy, Denali National Park, Cantwell,
Carlo Creek, Kantishna, Black Rapids, Donnelly Dome,
Trims DOT Camp, Eagle Trail, and Mineral Lake
214 PM AKDT Fri May 12 2023

...High Water Levels Likely Into Next Week...

A warming trend to near and above normal temperatures across the
eastern Interior, combined with a much above normal snowpack over
higher elevations, is causing a significant increase in snowmelt.
Runoff into rivers south of the Brooks Range during the next week
will cause water levels to rise and breakup to begin on many
rivers. Local ice jam may form and result in elevated water
levels. The increased runoff may also cause smaller streams and
creeks to rise to bankfull levels or overbank in low lying areas.

People along Interior rivers and streams should prepare for the possibility
of high water levels this week and next week due to ice breakup and
snowmelt runoff.

The latest breakup information is available at
www.weather.gov/aprfc/breakupMap.
Special weather statement, May 12, 4:01 PM AKST, 1 hour 36 minutes before
Special Weather Statement
National Weather Service Fairbanks AK
501 PM AKDT Fri May 12 2023

AKZ207>210-212>217-227-132115-
Chukchi Sea Coast-Lower Kobuk and Noatak Valleys-
Baldwin Peninsula and Selawik Valley-
Northern and Interior Seward Peninsula-
Eastern Norton Sound and Nulato Hills-
St Lawrence Island and Bering Strait Coast-Yukon Delta-
Lower Yukon Valley-Lower Koyukuk and Middle Yukon Valleys-
Upper Kobuk and Noatak Valleys-Upper Kuskokwim Valley-
Including Point Hope, Shishmaref, Kivalina, Espenberg, Noatak,
Kiana, Red Dog Mine, Kotzebue, Selawik, Noorvik, Buckland,
Deering, Candle, Council, Haycock, Pilgrim Springs,
Serpentine Hot Springs, Taylor, Unalakleet, Stebbins, St Michael,
Elim, Koyuk, Shaktoolik, Gambell, Savoonga, Brevig Mission,
Teller, Wales, Diomede, Mountain Village, Emmonak, Alakanuk,
Kotlik, Pilot Station, St Marys, Scammon Bay, Hooper Bay,
Marshall, Nunam Iqua, Pitkas Point, Russian Mission, Grayling,
Holy Cross, Shageluk, Anvik, Flat, Galena, Nulato, Huslia,
Kaltag, Ruby, Koyukuk, Ambler, Shungnak, Kobuk, McGrath, Nikolai,
Takotna, and Farewell Lake
501 PM AKDT Fri May 12 2023

...High Water Levels Possible This Weekend and Next Week...

A strong front moving east out of the Bering Sea will stall over
the area this weekend and into early next week. This front is
expected to bring strong southerly winds and heavy rain to the
West Coast and Western Interior. The heavy rain combined with an
above normal snowpack over higher elevations, will cause a
significant increase in snowmelt. Runoff into rivers along the
south faces of the Brooks Range southward to the Lower YK Delta
over the weekend and early next week will cause water levels to
rise and possibly begin the breakup process on many rivers. The
potential exists for local ice jams to form and result in elevated
water levels. The increased runoff may also cause smaller streams
and creeks to rise to bankfull levels or overbank in low lying
areas.

People along rivers and streams along the West Coast and in the
Western Interior should prepare for the possibility of high water
levels this weekend and next week due to ice breakup and snowmelt
runoff.

The latest breakup information is available at
www.weather.gov/aprfc/breakupMap.

AKZ211-132115-
Southern Seward Peninsula Coast-
Including Nome, White Mountain, and Golovin
501 PM AKDT Fri May 12 2023

...Minor Ice Shoves Strong winds and Heavy Rain Possible This
Weekend and Next Week...

A strong front moving east out of the Bering Sea will stall over
the area this weekend and into early next week. This front is
expected to bring strong southerly winds and the potential for
minor ice shoves along the Norton Sound coast from Nome to Golovin over
the weekend. Ice is expected to push onto the beach and pile up
the beach. There is a slight chance that ice could push inland
from the beach should stronger than expected sheets of ice push
onshore.

In addition, heavy rain is expected especially along
the south facing slopes of the Seward Peninsula through the
weekend and into early next week. The heavy rain combined with an
above normal snowpack over higher elevations, will cause a
significant increase in snowmelt. Runoff into rivers along the
south facing slopes of the Seward Peninsula over the weekend and
early next week will cause water levels to rise and the potential
to start the breakup process on many rivers. Local ice jam may
form and result in elevated water levels. The increased runoff may
also cause smaller streams and creeks to rise to bankfull levels
or overbank in low lying areas.

People along rivers and streams along the West Coast should
prepare for the possibility of high water levels this week and
next week due to potential ice breakup and snowmelt runoff. People
along the Norton Sound coast from Nome to Golovin should be
prepared for minor ice shoves this weekend with ice piling up on
the beach, and a slight chance that ice could push inland.

JB

The radar

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

Open the radar archive at this moment

Event by event

3 flood. Local standard time, as filed.

Flood, Upr Tanana Vly Fortymile

When
May 12, 5:37 PM AKST to May 13, 6:19 PM AKST
Where
Upr Tanana Vly Fortymile County, 1.95 mi WNW of Eagle to 1.26 mi NNW of Eagle
Cause
Ice Jam
Reported by
Local Official
Coordinates
64.794, -141.208

Ice jam flooding started late at night on May 12th and when the Riverwatch team landed in Eagle on May 13th (early afternoon) flood waters had receded leaving stranded ice well above the bank. The USGS river gage had a preliminary crest of 42 feet at 5 AM ADT on May 13th. Moderate flood impacts included damage to the seawall with the guardrail along the seawall was destroyed, stranded ice, and flooding on the road between Eagle and Eagle Village leaving the road impassable for a week due to stranded ice. Several structures in town were damaged by ice and floodwaters, including the Falcon Inn which had a high water mark of almost 2 feet into the finished basement. Preceding the ice jam, the river was at or above bank full, with Mission Road beginning to flood late afternoon of May 12th.

Prior to the Eagle event, there were multiple significant ice jams in Canada, including a 30-mile-long jam with the toe of the ice jam located approximately 30 miles upriver from Eagle on May 12th. This jam caused major flooding in Canada. Downstream of Eagle was a mix of intact ice sheets, open water, and an ice jam 8 miles downriver from the month of the Tatonduk River. Thus, conditions were ripe for ice jams to impact Eagle once the Canadian ice jam released, which occurred late at night on May 12th.

Flood, Yukon Flats Nearby Uplands

When
May 13, 6:30 PM AKST to May 14, 12:00 PM AKST
Where
Yukon Flats Nearby Uplands County, 0.56 mi N of Circle to 1.04 mi SSE of Circle
Cause
Ice Jam
Reported by
Local Official
Coordinates
65.838, -144.079

Record flooding occurred on the evening of May 13th at Circle. The Riverwatch team flew between Eagle and Circle on the afternoon of May 13th. During the day on May 13th, an observer 28 miles upriver of Circle reported the highest water he’d ever seen. The Riverwatch team observed widespread flooding (trees inundated, islands covered in ice, river well out of bank) upriver from Circle. Ice had degraded during the day in warm conditions and the Riverwatch team saw ice start to move while they were in Circle at 5 pm May 13th. Prior to landing, the Riverwatch team observed a roughly 90-mile-long run of ice behind the breakup front. For context, that is the longest run of ice that this Riverwatch team could remember ever seeing. The Riverwatch team circled above several times after takeoff and observed ice moving, and progressive disintegration of larger ice sheets (indicating weakness and that given the momentum of the river ice jams were unlikely). The flooding came on quickly; the water rose extremely fast and major flooding was first reported at around 8 pm. There was extensive damage, with flood waters estimated to be higher than the previous flood of record, 1945. The store had water up to the ceiling of the first floor. Ice moved into town and damaged homes with stranded ice throughout the community. Most structures in the town flooded and also flooded the airport apron and taxiway. The Riverwatch team flew over the next day and did not observe evidence of ice jamming but believe that the river simply slowed at the S-curves (where the Yukon becomes more braided) and compounded with historically high water levels. By the next morning, floodwaters had receded and had dropped below the airport access road by 3 pm May 14th.

Flood, Yukon Flats Nearby Uplands

When
May 14, 5:21 PM AKST to May 15, 4:18 PM AKST
Where
Yukon Flats Nearby Uplands County, 1.06 mi ESE of Ft Yukon to 3.05 mi SW of Ft Yukon
Cause
Ice Jam
Reported by
Local Official
Coordinates
66.612, -145.216

The breakup front progressed towards Fort Yukon on May 14th, finally stopping (jamming) just below Fort Yukon by late afternoon/evening. Water levels rose rapidly over bank and resulted in moderate flooding of the community. The river crested the night of the 14th. Several homes/structures were inundated with water. The tribal hall was flooded with water just up to the floor level with likely damage to the floor. The road to the east of the Tribal Hall was breached to help reduce water levels with water flowing through the breach and back towards the Yukon River. The levee held well and prevented more significant damages. A local observer reported that water levels came to within one foot of overtopping the low spots along the levee, and estimated that the water level was similar to 1981. Water started receding early in the morning of May 15th when the ice jam released. The water took several days to fully drop back within bank.

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

More

Every storm in Alaska in 2023Every state in 2023This day in weather historyWarnings in Alaska, May 2023

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: 1101977, 1101989, 1101990.