Flood — Copper River Basin, Alaska

2023-05-13 to 2023-05-18 · near Glennallen, Copper River Basin, Alaska

Event narrative

Snowmelt flooding pushed Moose Creek into flood across Glennallen, AK. The flood inundated the town of Glennallen, flooding homes, businesses and Glenn Highway at MP 185, forcing it to close. Flooding was extensive and a disaster declaration was declared for Glennallen on May 13, 2023 for the severe flooding.

Wider weather episode

An unusually cold spring kept snowpack intact and in place over the Copper River Basin into mid May. Once temperatures started to warm, they did so quickly and rapidly melted snowpack in the basin. An additional snow event later in May repeated the process creating multiple events where snowmelt would impact Glennallen and Old Edgerton Highway from Moose Creek snowmelt, and Gulkana and Sourdough areas along the Gulkana River.

View location on OpenStreetMap → (62.1089, -145.5527)

Source: NOAA Storm Events Database, event_id 1104522. Narrative written by the NWS forecast office that issued the report.