Animated map of Historical Tornadoes in the US
This animated map of historical tornadoes was created using SpreadsheetWeb Dashboard feature. You can create a density map from any geographical data that contains latitude and longitude information. SpreadsheetWeb can aggregate that data into a multi-color density map. Areas colored red indicates higher density of data points, while blue represents areas with fewest data points.
The data used in this map was downloaded from NOAA's National Weather Service Storm Prediction Center. The website provides information and data on severe weather events across United States including tornadoes, hail storms, and other weather related events. Historical tornadoes data used in the visualization can be downloaded directly from the link in CSV format. Data for other years and weather events can be downloaded from this link. You can import any CSV data into SpreadsheetWeb using its Data Import Utility.
Once the data is imported, the next step is to create a dashboard. Please watch this tutorial video to learn more on creating dashboards in SpreadsheetWeb.
Next, insert a visualization and select Map menu. Select density map from the list. See link for more on all map types. Select latitude and longitude information and press Create. The density map will include data for all years. Then go to Animation tab and select Year. This will create an animation where separate density maps of historical tornadoes are created for each year. The animation will load each map at 500ms intervals. You can change the interval for best result.