Any weather phenomenon that has "witch" in its title can’t be good news.
The “Witch of November," also called the “November Witch,” is the informal name for an unique and powerful storm system common to the Great Lakes in the autumn months, but most specifically in late October and November.
The "Witches" can be as strong as a hurricane, and have claimed hundreds of ships and thousands of lives over the centuries.
The Great Lakes are some of the world’s largest bodies of inland water, more like freshwater inland seas than lakes. Because of their vast size, they are able to develop their own weather systems.
At the end of the warm season, these lakes retain the heat energy that the summer sun has provided. Above the lakes, the atmosphere cools much more rapidly as the days grow shorter. The increased temperature difference between the water and the air creates low pressure, which in turn draws even more cold arctic air over the lakes.
The result of these actions are massive storms, marked by strong wind. The “witch” moniker may come from the howling and screaming sounds the wind makes when the trees are stripped of their leaves.
The sheer strength of these storms can be tremendous. The most powerful storm ever recorded on the Great Lakes occurred on October 26, 2010, when the pressure fell to 954mb, the equivalent of a category 3 hurricane. That storm brought winds of 140 km/h and onshore waves of nearly six metres.
The best known victim of these autumn gales was the 220-meter ore carrier “Edmund Fitzgerald” which sank in Lake Superior with all on board November 10, 1975, and was immortalized by Gordon Lightfoot’s now famous song.
The “Witches of November” claimed more than 6,000 vessels in the late 1800s alone, and it is estimated that in the past 300 years nearly 25,000 sailors have been casualties of these fall storms.