Flood Warning

A second release from Suicide Basin has started and levels continue to drop this afternoon. Levels on the Mendenhall have started to rise but will continue to rise as the release continues.

* WHAT...Flooding caused by a glacier-dammed lake outburst is expected.

* WHERE...The Mendenhall Lake And River near the Mendenhall Glacier Recreation area, View Drive and below Back Loop bridge.

* WHEN...Until 745 AM AKDT Saturday.

* IMPACTS...Flooding of the area around Mendenhall Lake and along the Mendenhall River is imminent. Water levels will continue to rise and water temperatures will fall within the lake and river.

Impacts: At 6.7 feet: Nugget Falls trail begins to flood near the "causeway" at the end of the trail. At 7.7 feet: Nugget Falls trail begins to flood near the beginning of the trail. Along the Mendenhall River some sections will experience bank erosion resulting in dangerous tree fall. These conditions could make floating the river more hazardous with the higher water levels. At 9.0 feet: Water starts to cover Skaters Cabin Road between Skaters Cabin and West Glacier Trailhead, also water will flow into the Mendenhall Lake Campground. At 10.0 feet: Water levels will inundate Mendenhall Campground with up to 3 feet of water covering low areas as well as up to 1.5 feet of water covering Skaters Cabin Road. Portions of West Glacier Trail will be impassable. Areas along View Dr will start to flood and cause minor flooding of yards. Closure of pedestrian pathways beneath Brotherhood Bridge and the trail system on the west side of Mendenhall River during outburst events.

* ADDITIONAL DETAILS... - At 741 AM AKDT, gauge data reported a glacier-dammed lake outburst. Flooding is expected to begin shortly, especially near The Mendenhall Lake And River. - The outburst flood forecast is based on an estimated volume of water in the glacier dammed lake and an estimated release rate based on previous events. The extent of water drainage within the basin (partial or full) can vary widely between outburst flood events and is a major source of uncertainty in the forecast, particularly with regard to the peak flood stage. - For Mendenhall Lake : At 7:15am the stage was 5.0 feet. Flood Stage is 9.0 feet. Forecast: A crest between 9.8 to 10.3 feet is expected around 2:00pm to 6:00pm Friday. Water levels will go above minor flood stage around 10:00am Friday. Water levels will reach moderate flood stage around 2:00pm to 6:00pm Friday.