Blizzards in the Upper Midwest
Copyright Lawrence Burkett 2015, minor rev. 2018
A blizzard is a severe snowstorm that is characterized by high winds and enough snow in the air to significantly reduce visibility near the surface. Sometimes blizzards are referred to as a type of winter storm; even though blizzards have occurred in other seasons (Wagner 1985; Kocin, Gartner and Graf 1998; Schwartz and Schmidlin 2002). Blizzards can close airports, businesses, churches, government offices, rail lines, roadways, and schools. Blizzards may also do damage to structures, sever utilities, and result in injury and loss of life (Schwartz 2004). For example, from 1959-2000 blizzards in the conterminous United States directly resulted in 679 deaths, 2,011 injuries, $22,600,000,000 worth of property damage, and $1,080,000,000 worth of crop damage adjusted to 2001 dollars Schwartz (2001).
Historically, numerous blizzards have impacted locations in the United States. According to Schwartz and Schmidlin (2002), blizzards occur and impact parts of the Dakotas and Minnesota more so than any other areas of the conterminous United States in a region referred to as the “blizzard zone” in their study of blizzards from 1959-2000. Prior to Schwartz and Schmidlin (2002), factual accounts of blizzards in parts of the Dakotas and Minnesota can be found in American literature dating back to the late 19th and early 20th Century with stories of pioneers, urbanites, sailors, and Native Americans battling the worst winter conditions.
In my study, Storm Data publications were used to study blizzard frequency in the Upper Midwest, a 45 county area covering 180,335 km2 in parts of Minnesota and North Dakota, as shown in Figure 1 using provincial, state, and county boundaries provided by the Environmental Systems Research Institute (ESRI).
Figure 1. County boundaries of the Upper Midwest are shown with thick black lines. Source: ESRI.
According to Branick (1997), Storm Data publications are more likely to contain reports of blizzards than other sources since the occurrence and duration of blizzards would probably require collocating simultaneous observations of snow, visibility, and wind speed as well as the type of any obstructions nearby at the surface. My study is a contribution to Branick (1997, 193) who addressed the need to develop a greater understanding of the mesoscale aspects of “winter-type” storms including blizzards. In addition, my study is also a refinement to Schwartz and Schmidlin (2002) who studied blizzards in the conterminous U.S. using Storm Data.
The landscape in the Upper Midwest is rural in comparison to other parts of the United States, and is primarily covered by a mixture of coniferous and deciduous forest in the east and open areas of croplands and prairie in the west. Differences in elevation in the Upper Midwest are on the order of a few hundred meters with hills dominating in the east and flat to gently rolling orography in the west. Substantial areas of human population in the Upper Midwest include the Duluth, Fargo and Grand Forks metropolitans, several Native American reservations, and a collection of other numerous smaller urban areas ranging from primarily farming and ranching towns in the west to forestry, mining, and lake resort communities in the east.