As of January 21st, 2020, the ice coverage of Lake Superior was only 6%. The historic average for this time of the year is 19 percent. Last year was around average with an ice coverage of 18%.
According to a scientist from the Great Lakes Environmental Research Laboratory, the estimated ice coverage for March will be 54% compared to the historic average of 64% based on long-term temperature forecasts.
Satellite imagery has shown a band of ice that has formed from Grand Marais to just east of Terrace Bay along the shoreline.
Along the southern shoreline pockets of ice have developed between Duluth and Sault Ste. Marie.
Jacob Bruxer, a Canadian representative on the International Lake Superior Board of Control has commented that the reduced ice cover may reduce lake levels through evaporation, but the driving factors of water levels are from precipitation and runoff which are highly variable.
Tracking ice cover is important to business and recreational use. Breaking the ice for shipping can be expensive for businesses and can result in lost revenue. Tourism such as the Apostle Islands ice caves are also affected by ice cover. Since ice coverage is so low this year, it is unlikely the caves will be open.
Ice coverage was 95% in March last year, which also happened in 2014 and 2015.
The last time Lake Superior completely froze was in 1996.
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