NOAA projects 30 per cent Great Lakes ice cover in 2021

NOAA – Scientists with the National Oceanic and Atmospheric Administration project the maximum Great Lakes ice cover for 2021 will hit 30 per cent, which would be well above last year’s maximum of 19.5 percent, but part of a long-term pattern of declining ice cover likely driven by climate change. The maximum typically occurs between mid-February and early March.

The 30 per cent projected maximum ice cover forecast for this winter is an average of maximum ice coverage across the five lakes.

Using an improved forecast system, scientists at the Great Lakes Environmental Research Laboratory will update seasonal ice cover projections twice a month.  Each iteration will take into account the most recent surface air temperature data leading to a more accurate forecast.

The experimental seasonal projections can provide general information to assist shippers, commercial and recreational vessel operators, anglers, coastal managers and the general public who live, work and recreate on and around our nation’s largest freshwater lakes.

“Great Lakes ice cover often swings back and forth between higher and lower levels with each new year,” said Jia Wang, ice climatologist at NOAA GLERL. “Global climate patterns such as El Nino play a major role in driving these changes. But if annual cycles are removed, a long-term trend is visible showing that overall ice cover has been declining by five percent per decade based on 1973-2020 data.”

Wang attributes the decline to human-caused climate change, primarily rising atmospheric temperature.

The 2021 maximum ice cover prediction of 30 per cent is significantly lower than the long-term average maximum coverage of 53 percent. The 2021 prediction is higher than the 2017 and 2020 maximums (both about 19.5 per cent) and much lower than the 2018 maximum of 70 per cent and the 2019 maximum of 81 per cent.