Flood — Yukon Flats Nearby Uplands, Alaska

2023-05-14 to 2023-05-15 · near Ft Yukon, Yukon Flats Nearby Uplands, Alaska

Event narrative

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.

Wider weather episode

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.

View location on OpenStreetMap → (66.6124, -145.2162)

Source: NOAA Storm Events Database, event_id 1101990. Narrative written by the NWS forecast office that issued the report.