Flood — Juneau Borough, Alaska

2011-08-22 to 2011-08-23 · near Douglas, Juneau Borough, Alaska

Event narrative

Lake and River levels on the Mendenhall system rose throughout the day on August 22 2011 from heavy rain fall that produced high rain rates from tropical moisture as an atmospheric river moved over the Juneau area. The river and lake stages reached moderate flood stage and produce flooding along view drive'Mendenhall campground and the spur road to Mendenhall Lake. The high rain rates diminished late in the event but the water levels continue to rise at high rate. The hydrograph was taking on a look like a glacier dam release took place and later it was verified that glacier dammed lake in Suicide Basin drained for a second time that summer.

Wider weather episode

Heavy rain fall from an atmospheric river moving over the Central Panhandle produced moderate flooding on the Mendenhall River/Lake system on August 22. Rain rates were greater than 0.1in per hour and these rain rates produced significant runoff. There was also indication that some of the flood waters was from a second release of the glacier dam in Suicide Basin that help raise the river and lake stages to be in the top 5 in history.

View location on OpenStreetMap → (58.4507, -134.5226)

Source: NOAA Storm Events Database, event_id 479307. Narrative written by the NWS forecast office that issued the report.