I grew up with the threat of a tornado in the back of my mind but I never thought anyone that I knew would be directly affected by one. Tornadoes were just an interesting weather event that I'd occasionally be reminded of when the tornado sirens were tested at 1pm on the first Wednesday of every month or when my normal after school TV programming was interrupted to tell me there was a tornado watch in my county. There were times when I was in the car while my dad drove us away from little league baseball games that had been canceled due to a tornado warning, peering out the window hoping to see even the smallest funnel in the sky. Yet, I didn’t actually expect the event that took place on Sunday, May 22, 2011. I was in 5th grade but I remember my best friend coming into class on Monday and signing up to share with the class at our morning meeting what had happened in her back yard the previous day. Somehow I was completely unaware of the tornado until she talked about how it swept through her neighborhood, uprooting trees and knocking down power lines.
Tornados, relative to other geohazards do not pose a significant risk to human life. Tornadoes with strengths low on the Enhanced Fujita (EF) Scale, like the one in Minneapolis, can cause a lot of property damage but they do not result in high death tolls. Those that do are rare. Only 10.7% of tornadoes are classified as an EF2 and only four percent of tornadoes are stronger than that. So, even though large tornadoes can be deadly, they don’t happen very often.
Tornadoes are formed when warm, moist air mixes with cool, dry air, creating a thunderstorm. From this, rotating air moving upwards meets rotating air moving downwards. Combined with air rotating near the ground, a tornado can form. Once a tornado is formed, they sweep across the land, leaving a lasting mark. In many cases, such as the tornado in North Minneapolis, tornadoes leave a visible scar and satellite images years later can still show the exact path a tornado took.
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| Fallen trees in North Minneapolis |
The tornado that swept through North Minneapolis in 2011, killing one person and injuring 30 more, was classified by the National Weather Service as an EF1 because it had winds between 86 and 110 miles per hour. Although it was classified as an EF1, the damage the tornado did was more consistent with EF2 tornadoes. Most of this damage came from large trees that were uprooted and then fell on top of houses or cars, though some of the damage was to power lines as well, putting nearly 22,000 people in the area out of power for a short amount of time. Because of all of the fallen trees, the Mayor and Police Chief even put a curfew in place to ensure that emergency workers could travel through the area more efficiently. Despite all of the physical harm the tornado caused, it was able to build community, as neighbors began helping neighbors rebuild what they had lost.
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| Fallen trees caused much of the property damage |
Tornados, relative to other geohazards do not pose a significant risk to human life. Tornadoes with strengths low on the Enhanced Fujita (EF) Scale, like the one in Minneapolis, can cause a lot of property damage but they do not result in high death tolls. Those that do are rare. Only 10.7% of tornadoes are classified as an EF2 and only four percent of tornadoes are stronger than that. So, even though large tornadoes can be deadly, they don’t happen very often.
Tornadoes are formed when warm, moist air mixes with cool, dry air, creating a thunderstorm. From this, rotating air moving upwards meets rotating air moving downwards. Combined with air rotating near the ground, a tornado can form. Once a tornado is formed, they sweep across the land, leaving a lasting mark. In many cases, such as the tornado in North Minneapolis, tornadoes leave a visible scar and satellite images years later can still show the exact path a tornado took.
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| The visible scar of the tornado's path, as seen by satellite |
References:
John Lauritsen. “North Minneapolis Still Cleaning Up, 7 Years After Devastating Tornado.” WCCO |
CBS Minnesota. WCCO | CBS Minnesota, May 21, 2018. https://minnesota.cbslocal.com/2018/05/21/north-minneapolis-tornado-seven-year-anniversary/.
Huttner, Paul. “North Minneapolis Tornado 7 Years Ago; Steamy and Thundery This Week.” MPR News. MPR News, May 22, 2018. https://www.mprnews.org/story/2018/05/22/north-minneapolis-tornado-7-years-ago-steamy-and-thundery-this-week.
McAuliffe, Bill, Randy Furst, Paul Walsh, and Heron Marquez Estrada. “Deadly Tornado Crashes through North Minneapolis.” Star Tribune. Star Tribune, May 18, 2012. https://www.startribune.com/may-22-2011-deadly-tornado-crashes-through-north-minneapolis/122417279/?refresh=true.
Walsh, Bryan. “How the National Weather Service Ranks the Strength of Tornadoes.” Time. Time, April 29, 2014. https://time.com/81238/tornado-ranking/.
“How Tornadoes Form.” UCAR Center for Science Education. Accessed April 5, 2020. https://scied.ucar.edu/learning-zone/storms/how-tornadoes-form.
CBS Minnesota. WCCO | CBS Minnesota, May 21, 2018. https://minnesota.cbslocal.com/2018/05/21/north-minneapolis-tornado-seven-year-anniversary/.
McAuliffe, Bill, Randy Furst, Paul Walsh, and Heron Marquez Estrada. “Deadly Tornado Crashes through North Minneapolis.” Star Tribune. Star Tribune, May 18, 2012. https://www.startribune.com/may-22-2011-deadly-tornado-crashes-through-north-minneapolis/122417279/?refresh=true.
Walsh, Bryan. “How the National Weather Service Ranks the Strength of Tornadoes.” Time. Time, April 29, 2014. https://time.com/81238/tornado-ranking/.
“How Tornadoes Form.” UCAR Center for Science Education. Accessed April 5, 2020. https://scied.ucar.edu/learning-zone/storms/how-tornadoes-form.
I didn't realize that tornadoes could happen in the Cities. Do you remember any others prominently?
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