Weather Phenomenon Capsizes Boat on Lake Michigan

An extremely rare weather phenomenon this week caused a boat to capsize on Lake Michigan in Illinois.

The boat capsized just off 31st Beach in Chicago on Tuesday after a sudden gust of wind drastically changed temperatures in the area, WFLD reported. All individuals on board were rescued.

The incident was caused by a weather phenomenon exclusive to the area known as a "pneumonia front." It occurs when cool winds off Lake Michigan accelerate inland, causing temperatures to drop drastically.

The term was coined in the 1960s by the National Weather Service, and describes the moment when the temperature drops by up to 16 degrees Fahrenheit for around one hour at a time. It usually occurs in April through to July.

Boats can capsize in response to all kinds of severe weather conditions. But the sharp gust of wind following the pneumonia front is most likely to be the case in this incident.

Capsizing can happen when those onboard are caught of guard by a sudden wind, or when the weight of the boat is unevenly distributed.

This particular pneumonia front was predicted by the National Weather Service just a few days before it hit the area.

Experts later reported that it caused temperatures to drop 24 degrees in less than an hour. Southwest Wisconsin was also affected.

Local boater John Stepney told WFLD that before the wind hit the area, the lake was "pretty flat."

"It looked like glass coming in from around the museum," he said. "Those are nice days to be out."

The sudden change in temperatures can sound dramatic, but it usually passes quickly. In a separate report, WITI said that even after it passed on Tuesday, conditions would remain noticeably cooler for a few days.

By volume, Lake Michigan is the second largest of the Great Lakes behind Lake Superior and third largest by surface area behind Superior and Lake Huron. As it is so large that it is able to generate its own weather patterns.

The lake plays a huge role in influencing the climate and temperature of Chicago and other parts of Illinois and Wisconsin. The lake breeze works to cool the summer temperatures but can also provide warmth during the winter. Cold air masses sweeping across the lake can also increase snow or rainfall.

In February, 25 people were rescued from moving ice floes on Lake Michigan. Experts believe that this showed the lake to be warmer than usual, as the ice was not as thick as it normally is at that time of year.

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