The Great Lakes Storm of 1913, historically referred to as the "Big Blow,"[A] the "Freshwater Fury," or the "White Hurricane," was a blizzard with hurricane-force winds that devastated the Great Lakes Basin in the Midwestern United States and the province of Ontario in Canada from November 7 through November 10, 1913. The storm was most powerful on November 9, battering and overturning ships on four of the five Great Lakes, particularly Lake Huron. Deceptive lulls in the storm and the slow pace of weather reports contributed to the storm's destructiveness.
The deadliest and most destructive natural disaster to hit the lakes in recorded history, the Great Lakes Storm killed more than 250 people, destroyed 19 ships, and stranded 19 others. The financial loss in vessels alone was nearly US $5 million (or about $123,805,000 in today's dollars). This included about $1 million at current value in lost cargo totalling about 68,300 tons, such as coal, iron ore, and grain.
The storm, an extratropical cyclone, originated as the convergence of two major storm fronts, fueled by the lakes' relatively warm waters—a seasonal process called a "November gale". It produced 90 mph (145 km/h) wind gusts, waves over 35 feet (11 m) high, and whiteout snowsqualls. Analysis of the storm and its impact on humans, engineering structures, and the landscape led to better forecasting and faster responses to storm warnings, stronger construction (especially of marine vessels), and improved preparedness.
The immense volume of water in the five Great Lakes holds heat that allows the lakes to remain relatively warm for much later into the year and postpones the Arctic spread in the region. During the autumn months, two major weather tracks converge over the area. Cold, dry air moves south/southeast from the province of Alberta and northern Canada; warm, moist air moves north/northeast from the Gulf of Mexico, along the lee of the central Rocky Mountains. The collision of these masses forms large storm systems in the middle of the North American continent, including the Great Lakes. When the cold air from these storms moves over the lakes, it is warmed by the waters below and picks up a spin. As the cyclonic system continues over the lakes, its power is intensified by the jet stream above and the warm waters below.
The result is commonly referred to as a "November gale" or "November witch." Such a storm can maintain hurricane-force wind gusts, produce waves over 50 feet (15 m) high, and dump several inches of rain or feet of snow. Fuelled by the warm lake water, these powerful storms may remain over the Great Lakes for days. Intense winds ravage the lakes and surrounding shores, severely eroding and flooding the shorelines.