Mendenhall Glacier Flood Outburst 2026; Juneau, Alaska

Juneau, AK, USA | 2026-Aug-11

Initial Notification: A glacial lake outburst has occurred at Suicide Basin on the Mendenhall Glacier. The basin is releasing. Flooding is expected along Mendenhall Lake and River late Wednesday evening into early Thursday morning. A crest between 16.1 and 16.6 ft in Major Flood Stage is expected between 5 am and 9 am Thursday, 8/13/2026. People living in the potential inundation area (~1,900 residences) are advised to evacuate today (8/12/2026). No NOAA facilities are located in the evacuation area. Previous to this event, the U.S. Coast Guard requested guidance on the fate and trajectory of a worst case discharge of the fuel storage tanks in the inundation zone.