Tornado Risk Index Rating, County, National Risk Index

<p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><span style='font-family:inherit; font-size:large;'><font style='border:0px solid currentcolor; box-sizing:border-box; font-family:inherit; line-height:1.5;'><span style='border:0px solid currentcolor; box-sizing:border-box; line-height:1.5;'><strong>National Risk Index Data Version: December 2025 (1.20.0)</strong></span></font></span></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><strong>A tornado is a narrow, violently rotating column of air that extends from the base of a thunderstorm to the ground and is visible only if it forms a condensation funnel made up of water droplets, dust, and debris.</strong></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><span style='background-color:rgb(255,255,255); color:rgb(20,20,20); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px;'><span style='display:inline !important; float:none; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>The Tornado Risk Index Rating, County, National Risk Index view feature layer contains Risk Index data for tornado at the county level.</span></span></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>The <a style='border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;' target='_blank' href='https://www.fema.gov/flood-maps/products-tools/national-risk-index' rel='nofollow ugc noopener noreferrer'>National Risk Index</a> data helps to illustrate the communities most at risk for 18 natural hazards across the United States and territories: avalanche, coastal flooding, cold wave, drought, earthquake, hail, heat wave, hurricane, ice storm, inland flooding, landslide, lightning, strong wind, tornado, tsunami, volcanic activity, wildfire, and winter weather. The National Risk Index data provides Risk Index values, scores and ratings based on data for Expected Annual Loss due to natural hazards, Social Vulnerability, and Community Resilience. Separate values, scores and ratings are also provided for Expected Annual Loss, Social Vulnerability, and Community Resilience. For the Risk Index and Expected Annual Loss, values, scores and ratings can be viewed as a composite score for all hazards or individually for each of the 18 hazard types.</p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>Sources for Expected Annual Loss data include:</p><ul><li>Arizona State University’s Center for Emergency Management and Homeland Security</li><li>California Department of Conservation – Geological Survey</li><li>Colorado Avalanche Information Center</li><li>Snow Data Assimilation System</li><li>National Water and Climate Center</li><li>Snow Survey and Water Supply Forecasting Program</li><li>Snow Telemetry Network</li><li>Northern Hemisphere 0.25 Degree Resolution Machine Learning Snow Depth Data</li><li>CoreLogic’s Flood Services</li><li>Federal Emergency Management Agency</li><li>National Flood Insurance Program</li><li>FEMA Natural Hazards Risk Assessment Program</li><li>Humanitarian Data Exchange</li><li>Iowa State University's Iowa Environmental Mesonet</li><li>Multi-Resolution Land Characteristics Consortium</li><li>National Earthquake Hazards Reduction Program</li><li>National Oceanic and Atmospheric Administration’s National Centers for Environmental Information</li><li>National Oceanic and Atmospheric Administration's National Hurricane Center</li><li>National Oceanic and Atmospheric Administration's National Weather Service</li><li>National Oceanic and Atmospheric Administration's Office for Coastal Management</li><li>National Oceanic and Atmospheric Administration's National Geophysical Data Center</li><li>National Oceanic and Atmospheric Administration's Storm Prediction Center</li><li>U.S. Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory</li><li>U.S. Census Bureau</li><li>U.S. Department of Agriculture's National Agricultural Statistics Service</li><li>U.S. Forest Service's Fire Modeling Institute's Missoula Fire Sciences Lab</li><li>U.S. Geological Survey</li><li>U.S. Geological Survey's Landslide Hazards Program</li><li>U.S. Geological Survey Western Geographic Science Center Hazard Vulnerability Team</li><li>United Nations Office for Disaster Risk Reduction</li><li>University of Alaska – Fairbanks' Alaska Earthquake Center</li><li>University of Nebraska – Lincoln's National Drought Mitigation Center</li></ul><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>&nbsp;</p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>Data for Social Vulnerability are provided by the U.S. Census Community Resilience Estimate, and data for Community Resilience are obtained from the University of South Carolina's Hazards and Vulnerability Research Institute’s 2020 Baseline Resilience Indicators for Communities. These obtained data were used to create a FEMA modified version of the Baseline Resilience Indicators for Communities for use in the National Risk Index dataset.</p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>The source of the boundaries for counties and Census tracts are based on the U.S. Census Bureau’s 2021 TIGER/Line shapefiles, except for Connecticut which uses the 2024 TIGER/Line shapefiles. &nbsp;Building value and population exposures for communities are based on FEMA’s Hazus 6.0 and inflation adjusted to December 2024 dollars. &nbsp;Agriculture values are based on the U.S. Department of Agriculture 2017 Census of Agriculture and inflation adjusted to December 2024 dollars.</p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><a style='border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;' target='_blank' href='https://fema.maps.arcgis.com/sharing/rest/content/items/e77b087b362f42d68ddbdbcab1c29d00/data' rel='nofollow ugc noopener noreferrer'>National Risk Index Dataset - Metadata</a></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><a style='border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;' target='_blank' href='https://fema.maps.arcgis.com/sharing/rest/content/items/4b9db412e99542029b3c37c37ad714bb/data' rel='nofollow ugc noopener noreferrer'>National Risk Index Dataset - Data Dictionary</a></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><a style='border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;' target='_blank' href='https://fema.maps.arcgis.com/sharing/rest/content/items/6835fa58ad5646878860145288c7cc39/data' rel='nofollow ugc noopener noreferrer'>National Risk Index Dataset - Data Glossary</a></p><p style='background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1.5rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'><a style='border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;' target='_blank' href='https://www.fema.gov/sites/default/files/documents/fema_national-risk-index_technical-documentation.pdf' rel='nofollow ugc noopener noreferrer'>National Risk Index Dataset - Technical Documentation</a></p>