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2024 Hennepin County All -Jurisdiction Hazard Mitigation Plan <br />Volume 2 — Hazard Inventory <br />The Armistice Day storm of November 11, 1940 <br />Is best remembered as high -impact, high -mortality blizzard, but the extreme winds prior to the <br />snow were responsible for much of the cascading disaster that followed. Extreme non -convective <br />winds capsized skiffs used by hunters in southern Minnesota, and produced impossible navigation <br />on the Mississippi River, which forced at least 12 hunters to shelter on islands, where they <br />ultimately froze to death. The winds wrecked large vessels on Lakes Michigan and Superior, <br />resulting in 59 fatalities. From Minnesota east into Michigan and Ohio, winds were sustained at <br />35 mph or greater for several hours, with many stations recording average speeds more than 50 <br />mph. Gusts of 70-80 mph are believed to have been common throughout the region. The <br />strongest winds were over <br />Wisconsin Illinois and western <br />Michigan, to the south and ° <br />southeast of the intensifying low- <br />pressure center. The winds blew <br />down utility poles, and cut power <br />and communications to much of z, <br />Minnesota, Wisconsin, Illinois, -pr <br />and <br />dangerous Michigan, Brous situation creating as <br />g <br />temperatures fell into the teens . k .,"L._ <br />and single digits. ° r f <br />The event produced all four en <br />extreme wind scenarios a %""', <br />g described previously in different <br />..A <br />parts of the region. Across much Surface weather map, Nov11, 1940. Shaded area represents <br />of Wisconsin, Lake Michigan and region of wind impacts. Dark area represents hurricane force <br />Lower Michigan, the dangerous, wind gusts. Modified from La Crosse NWS. <br />prolonged winds of 40-60 mph <br />(gusting up to 80 mph) were the only significant hazard posed by the storm. Over Iowa and Illinois, <br />tornadoes and severe thunderstorms swept through the area during the morning, and then non - <br />convective sustained winds of 25-45 mph (gusting 55-70 mph) blew for 8-12 hours following the <br />passage of the strong cold front. Over western Iowa, much of Minnesota, northwestern Wisconsin <br />and the eastern Dakotas, non -hazardous weather gave way to strong winds gusting up to 70 mph, <br />severe blizzard conditions, and dramatically falling temperatures; these conditions stranded and <br />killed at least two dozen motorists. Lastly, the central and western Dakotas had wind gusts to 65 <br />mph, little or no snowfall, but dangerously cold temperatures. <br />On October 10,1949 <br />The most severe non -convective wind event on record in Minnesota struck most of the state and <br />produced over 75,000 square miles of derecho-level damage. Minneapolis recorded seven <br />straight hours of sustained winds above 40 mph, three hours of sustained winds above 50 mph, <br />and two hours of gusts exceeding 75 mph, including a maximum gust of 89 mph. In Rochester, a <br />100-mph wind gust was recorded. Boat works facilities were demolished on Lake Minnetonka, as <br />well as numerous other Minnesota lakes; docks were destroyed, and sailboats were piled onto <br />the shores of Minneapolis lakes; windows were blown out of homes, storefronts, and office <br />buildings; and many brick buildings partially collapsed. In downtown Minneapolis, large <br />signboards were twisted, the 65-foot chimney of the Sheridan Building fell onto and severely <br />192 <br />