The Connection: Ice Coverage & Lake Effect Snow

We’re going to pause from our Great Lakes tour for a post or two. Right after the new year, a number of you sent me this article from the Washington Post – or others on the same topic. The Great Lakes were in the news.

January 1st, 2024 recorded the smallest amount of ice cover over the Great Lakes in the past 50 years. Only 0.35% of the lakes’ surface area was under ice. The lakes average 9% for New Year’s Day. There is clear evidence of a downward trend likely due to climate change. Between 1973 and 2017, the lakes recorded as many as 46 fewer days per season frozen, which is defined as days when at least 5% of the lakes’ surface had ice cover.

There is variability year to year – 2019 was one of the highest ice coverage years on record (81% coverage at one point!), and things can also change through a season. Highest ice coverage is usually seen in February and early March.  

Why does this matter? The National Atmospheric and Oceanic Administration (NOAA) has provided a helpful answer.

There are several challenges to note. Thick ice protects the shoreline from erosion and flooding during winter storms. Animal patterns are disrupted, including those of fish who use ice for protection during their spawning season. Some areas of the Great Lakes have developed winter recreational seasons for things like ice fishing that depend on ice coverage.

But one of the main impacts of this shift for those living in the region is an increase in the well-known lake effect snow phenomenon. Lake effect snow occurs when cold air, often a front from Canada, sweeps across the relatively warmer waters of the Great Lakes. As it moves, warmth and moisture from the lake water rises into the lowest portion of the atmosphere. Because it is warmer and less dense than the cold air, it rises and creates clouds and snow.

Unfrozen lake is a prerequisite for lake effect snow. So, with less ice coverage at the start of January, the region was ripe for the impacts of lake effect snow, and we saw it in the middle of the month when a frigid front came through and we saw substantial snowfall.

For those of us living in the region, there is high variability with how lake effect snow is experienced. It can sometimes bring a light, innocuous, low density snow. But it can also bring strong bands of dense snow that can appear quickly, at times causing dangerous conditions for driving. Climate change and warmer temperatures will likely exacerbate the extremes causing punishing snows like those Buffalo experienced in the closing days of 2022 when between 50 and 77 inches of snow fell around the region.

In sum, climate change is driving a deep irony for the Great Lakes region. Warmer temperatures are moderating the climate overall, but increasing some of the most extreme winter weather that drives stereotypes and boastful declarations about the superior liveability of places like Florida and the Sunbelt. I encourage you to think critically about this sentiment though. Winters here can have some extremes but summers there have some extremes – and in some places dwindling access to freshwater. There is nowhere to escape our warming planet. We all have burdens to bear in the short and long-term. 

And, as I shared in one of my earliest posts about retreating from life on Lake Erie in the winter of 2021, the snow and ice can be mighty beautiful.