The NOAA Great Lakes Environmental Research Laboratory (GLERL) has posted its annual experimental Great Lakes maximum ice cover projection for the winter of 2021-2022. The most recent experimental forecast, updated on January 13th, predicts a maximum Great Lakes ice cover of 48.7% – slightly lower than the average annual maximum ice cover (AMIC) of 54.5% since 1973.
Every year at the start of winter, GLERL’s ice climatologist Dr. Jia Wang uses a statistical regression model based on global teleconnections (air circulation patterns) to create GLERL’s seasonal ice forecast.
Each lake gets its own prediction.
In addition to forecasting maximum ice cover for the entire Great Lakes basin, GLERL’s experimental ice forecast also predicts ice cover lake-by-lake. The predicted maximum seasonal ice cover for each lake is as follows:
- Lake Superior = 52.3% (long-term average AMIC is 62.3%)
- Lake Michigan = 37.9% (long-term average AMIC is 41.4%)
- Lake Huron = 51.1% (long-term average AMIC is 65.0%)
- Lake Erie = 70.7% (long-term average AMIC is 81.9%)
- Lake Ontario = 12.9% (long-term average AMIC is 31.4%)
Although ice cover is only around 15% right now, there’s still plenty of winter left for further freezing. Historically, much of the major freezing of the Great Lakes happens in February.
What do global air patterns have to do with Great Lakes ice?
Our research has shown that the interannual variability of Great Lakes ice cover is heavily influenced by four large-scale climate patterns referred to as teleconnections: the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO), the El Nino/Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). These projected teleconnection pattern indices are produced by other agencies such as NOAA’s Climate Prediction Center. These teleconnection patterns impact Great Lakes regional climate and ice cover by influencing the location of the westerly jet stream over North America. The position of the jet stream largely dictates the origin of the air masses (e.g. North Pacific or the Arctic) that will reach the Great Lakes region as weather systems move across the continent. The temperature and moisture content of these air masses play a key role in determining ice cover.
2022 ice forecast compared to previous years
According to Wang, if the cycles of annual variability are removed, a decadal trend becomes visible, showing that overall ice cover has gone down by five percent max ice cover per decade based on 1973-2020 data. The 2022 maximum ice cover prediction of 48.7% is about 5.8% lower than the long-term average of 54.5%.
On average, the Great Lakes annual maximum ice cover is decreasing by about a half percent per year, or 5% per decade. Below is a table of the percentage decrease for each lake. With the exception of Lake Huron, these trends are all considered statistically significant, meaning we are 95% certain that the trend is not due to random chance.
NOAA GLERL continues to refine this experimental ice forecast model and conduct further research to continually improve it. Learn more about our Great Lakes ice research, current conditions, forecasting and more on our Ice Cover homepage.
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