The gales of November. I’m sure you’ve heard this phrase before. Perhaps it was in context of Robert J. Hemming’s novel, “The Gales of November: The Sinking of the Edmund Fitzgerald.” Aside from history or pop cultural references, the phrase actually has a sound context within the realm of meteorology, as November is considered the deadliest month for the Great Lakes.
In November visibility goes down due to fog, and strong winds increase causing dangerous boater conditions across the Great Lakes. Some of the worst and most fatal ship wrecks in terms of loss of life in history, like the story of the Edmund Fitzgerald, happened during the month of November on the Great Lakes.
Fog becomes an issue due to the temperature clash that occurs between the first cold blasts of air of the season hitting the lakes that are still relatively warm from the summer. Water takes longer to heat up and cool down so even when the land gets cold, the lakes stay warm for longer. For the science nerds out there, this is called the “specific heat” or “heat capacity” of water. And cold air riding over the warm lakes is the same process that causes lake effect snow.
In addition to the increase in fog, the winds really get cranking across the Great Lakes in November. The temperature clash between cold, dry polar air and warm, moist air from the Gulf of Mexico are also to blame. The meeting point of these two air masses is an area of low pressure, called a mid-latitude cyclone. These storm systems are large and can get incredibly wound up as they move north and east, especially when they battle with areas of high pressure nearby. Strong winds are caused by the difference in air pressure in the atmosphere, in the form of high and low pressure areas. The lower the low pressure and the higher the high pressure, the greater the difference between the two. That’s called the pressure gradient.
This is exactly what happened two weeks ago. Storm warnings as well as gale warnings went up for the area over the Lake as well as coastal locations warning for strong winds and battering waves. Over Lake Michigan, wind gusts up to 60 mph and wave heights of 25 feet were recorded by buoys. On the coast, sustained winds of 30 mph, gusts to 60 mph, and waves up to 20 feet crashed along the shore.
Hundreds of people flocked to the shores of Lake Michigan to see the big waves for themselves. Some were even brave enough to surf the swells. The National Weather Service office in Grand Rapids, Mich., actually noted that their greatest concern wasn’t so much the strong winds bringing trees down and causing power outages or coastal flooding from the large waves, but actually keeping people off the piers and jetties so they wouldn’t get swept away by the angry and turbulent water. In one of their forecast discussions they noted, “large waves will over-top even tall piers.”
Judging by the picture below, they were right — and for reference, that light house is 35 feet tall.
Weather is awesome. #cwgpicoftheweek
