It’s almost May and a third of the Great Lakes is still covered by ice. This is unprecedented in records dating back more than three decades, and it’s not even close.
Environment Canada’s Great Lakes ice dataset, which extends back to 1980-81, shows the current ice extent at a chart-topping 32.8 percent as of April 22. The year with the next greatest ice extent on this date, 1996, had about half as much ice – or 16.49 percent coverage. The average Great Lakes ice cover right now is 2.2 percent. There is roughly 16 times more ice than normal right now!
NOAA’s Great Lakes ice cover data agree. Its analysis as of April 22 indicates 33.9 percent ice coverage over the Lakes.
Reports Bill Steffen, a broadcast meteorologist in Grand Rapids, Michigan: “Ice cover on Weds. 4/23 was at 17.2% on Lake Michigan, 59.5% on Lake Superior, 31% on Lake Huron, 10.2% on Lake Erie and 1% on Lake Ontario.”
The Great Lakes ice cover has been above normal since the late fall. The chart below shows this year’s time series and the light green line represents the historical median – depressed well below 2014’s ice prosperity.
In early March this year, the Great Lakes ice extent reached 94.19%, the second most on record for any month, dating back to 1973 in NOAA’s dataset, and most on record so late in the season.