Experts issue warning as iconic lake sees hottest water temperature on record: 'Careful what you wish for'

Michigan-based meteorologist Mark Torregrossa, writing for MLive, updated locals about an unprecedented condition in Lake Michigan's water temperature and what it could mean for the coming winter.

What's happening?

Lake Michigan is the third-largest lake in the United States, spanning four states — Illinois, Indiana, Michigan, and Wisconsin — and 22,300 square miles.

According to Torregrossa, Lake Michigan water temperature tracking as it occurs today began back in 1995, when weather data-gathering satellites first began monitoring the Great Lakes' surface temperatures on a daily basis.

As such, meteorologists have three decades of day-to-day data from which to draw and contrast with current conditions. On Oct. 9, Lake Michigan's water temperatures were the highest they'd ever been on that date since modern tracking started.

"We can't say this is the warmest Lake Michigan's surface has ever been, but we can say it's the warmest for Oct. 9 since back to 1995," Torregrossa explained.

In the aggregate, he noted that Lake Michigan currently had "an overall surface temperature of 65.6 degrees," closer to 63 degrees in the north and 68 degrees in the south. However, the "long-term average surface water temperature for Oct. 9" stood at 59.4 degrees.

Torregrossa noted that the spread of 6.2 degrees didn't sound like much, but emphasized that it was a cumulative figure applicable to "all of the surface water of one of the largest lakes in the world," one that could impact the severity of winter weather in Michigan.

Why is Lake Michigan's water temperature concerning?

It has long been established that rising temperatures on land, at sea, and in freshwater lakes are a consequence of human activity, one with massive knock-on effects.

Perhaps most noticeable among those outcomes is extreme weather. 

Extreme weather is often wildly misunderstood or misrepresented, and the term doesn't describe intense weather like hurricanes, flash floods, or heatwaves. Those weather patterns have always been a part of the climate, and extreme weather is different and more dangerous.

How often does the temperature get over 100 degrees where you live? Never 😎 Once or twice a year 😓 Several times a year 🥵 Most of the summer ☀️ Click your choice to see results and speak your mind.

As temperatures continue rising at a rapid clip, hotter air and water have a distinct, measurable effect on weather systems. 

Hurricanes, wildfires, and floods still occur, but this cycle of accelerated evaporation supercharges already dangerous weather systems. When they occur, they strike harder and faster, leaving immense destruction and death in their wake.

Torregrossa alluded to "a ton of pent-up energy" resulting from higher water surface temperatures, energy that could translate to heavy rain or snow in lake-effect areas.

What's being done about it?

Understanding how an overheating planet produces extreme weather is important, and many commenters on MLive's Facebook post demonstrated why.

"You guys say this every year lol," a commenter wrote, prompting a response from a frustrated user.

"You're so close to getting it," they replied, alluding to the fact that the other commenter unwittingly identified an annual warming trend that should cause further concern rather than a reason to dismiss the report.

Warm winter weather "can cause rain instead of snow," a third user pointed out, "which could then become ice." "Careful what you wish for," they cautioned.

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