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2024 Hennepin County All -Jurisdiction Hazard Mitigation Plan <br />Volume 2 — Hazard Inventory <br />Sources and locations of US non -convective wind fatalities, modified from Ashley and Black 2008 (see references) <br />Unlike derechos, the peak frequencies of non -convective extreme winds occur during the mid -spring and <br />especially mid -fall transition seasons. This timing minimizes the number of outdoor recreational activities <br />and reduces the potential exposure to wind -related hazards. The notable exceptions are 1) Minnesota's <br />fishing opener, typically during the first half of May, at the end of the spring risk period, and 2) Minnesota's <br />hunting seasons, which span the heart of the peak risk in October and November. <br />Boaters face substantial risks during non -convective high wind events. The reduced friction of open water <br />often increases wind speeds and wave heights and threatens to capsize boats. Once overturned or <br />submerged, a boat's occupants will be subject to the seasonally cold water, which poses serious risks for <br />hypothermia and eventual drowning. Given the harsh conditions, rescue operations can be difficult, if not <br />impossible. Several of the known deaths during the Armistice Day storm of 1940 were from skiffs that <br />capsized in the 40-60 mph winds, hours before snow began to fall. <br />The prolonged nature of non -convective high wind events means that hunters and others spending time <br />outdoors face extended risk exposure from falling trees. In urban or built-up areas, falling trees and power <br />lines are the most typical sources of risk. During extreme events, urban inhabitants can be injured or killed <br />by flying debris. In rural areas, outbuildings are often damaged, and barns frequently collapse. <br />187 <br />