This is a developing story.
An uncharacteristic late-October glacial outburst flood from Suicide Basin caused the Mendenhall River to crest at 10.77 feet at 11:30 p.m. Sunday — both earlier and lower than had been forecast, according to the National Weather Service Juneau.
A drop in Suicide Basin’s water level observed Thursday night had forecasters on Saturday morning predicting a river level of up to 11.5 feet between 1 and 4 a.m. Monday. But Grant Smith, a NWS Juneau meteorologist, said in an interview at about 12:45 a.m. Monday the water level has been declining steadily since the reported crest and was at about 10.3 feet as of 12:30 a.m.
“The laser sensor was showing that we were at the bottom of what has been measured as the base of the bottom of the basin,” he said. “So at this point we’re thinking it’s done.”
While the water is retreating, temperatures in the Mendenhall Valley at about 12:45 a.m. were 23 degrees, Smith said. That means streets and other surfaces covered with water will become icy.
Also, NWS Juneau warns at its Suicide Basin monitoring website, “mariners should be advised during the outburst event, numerous trees and debris have been reported in the river and have may washed downstream.”
• Contact Mark Sabbatini at mark.sabbatini@juneauempire.com or (907) 957-2306.
