This map service displays the number of violent tornados by decade from 1950 to 2010 for U.S. states and counties. All  Enhanced Fujita scales classifications are included (http://www.spc.noaa.gov/faq/tornado/ef-scale.html). Information on fatalities and injuries is also included.
This map depicts tornadoes and violent tornadoes per decade decade from 1950 to 2009, including data from 2010 and 2011. The purpose is to show the change in tornado frequency by US County, State, and urban areas over the last six decades. Also shown is the total number of violent tornadoes, classified as category four or five on the Fujita Scale by the National Weather Service. The final decade contains data for 2010 and 2011 only. At the largest scales, tornado and violent frequency is shown by urban areas. Pop-ups contain information about the total numbers of violent tornadoes, injuries, and fatalities by state. The National Oceanic and Atmospheric Administration and US Census Bureau provided the data for this map.
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{'Title': 'Historic Tornados in the United States', 'Author': 'Esri', 'Comments': 'This map service displays the number of violent tornados by decade from 1950 to 2010 for U.S. states and counties. All  Enhanced Fujita scales classifications are included (http://www.spc.noaa.gov/faq/tornado/ef-scale.html). Information on fatalities and injuries is also included.', 'Subject': 'Number of tornados by state and county from 1950 to 2010.', 'Category': '', 'AntialiasingMode': 'None', 'TextAntialiasingMode': 'Force', 'Keywords': 'tornados,tornadoes,NOAA,United States,tornado tracks,Enhanced Fujita Scale,wind speed'}
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