ABOUT WEBSITE

Tornado Stats is a resource for interacting with and visualizing multiple tornado data sources for the United States. Most of the data used by this website is collected from the Storm Prediction Center’s public archives. Tornado HQ is referenced for live tornado alerts and warnings. This website is not an official source of information for tornado research; it should be used as a visual aid for understanding specific weather trends throughout the country. The primary focus of this website is the interactive web map, which interfaces with the SCP's database for tornado events in the United States. The year 1950 marked a milestone in weather history, with the first deployment of radar storm tracking and public tornado warnings. This year marks the beginning of the tornado data base used by the National Weather Service. For this reason, this website will not include records prior to 1950.

STATISTICAL METHODS

All statistics calculations follow a discrete probability distribution. No additional factors, such as changing weather conditions or geography, are accounted for when performing the calculations. As such, the calculations only provide a very rough estimate and should not be relied upon. Also, keep in mind that broader search queries will return more results, and thus more accurate statistics. We do not recommend color coding by probability when strict filters are enabled.

HOW TO USE INTERACTIVE MAP

The interactive tornado map can be accessed from anywhere on this website by clicking on the "Interactive Map" heading or the TornadoStats logo in the header section located at the top of the webpage. By default the map will display boundaries for all the counties in the United States, however this can be disabled in the layer section in the map submenu. I recommend keeping this feature enabled unless you are not interested in county data. The submenu can be revealed and hidden by toggling the menu icon located at the top left of the map. The submenu consists of four sections, which we will discuss shortly. Map filters can be combined in any matter of ways to query to database for different information.

After you select your desired filters, you will need to press the "run query" button on the bottom of the submenu. Once a query has been ran, the map will change to represent the data. To help you to interpret the data, refer to the legend section in the submenu. This legend will dynamically change depending on the type of query. All elements on the map are objects storing dynamic information. To view a specific county's data, search for the county name in the map search bar or click the county's polygon. This will reveal a popup display with important data relating to that county. The map style can be changed via the edit profile menu if you have made an account (free!). In the following sections, we will go over each of the filters and layers available on the map. You can find examples of various filter combinations at the bottom of this webpage.

MAP FILTERS:

Probability

Click this filter to calculate and visualize probabilities of events matching your query criteria occuring within a specified time range. The time range extends from 1 day to 100 years. For example, if you wish to know a rough estimate on an f4 tornado occurring in any given county in the next 20 years, you would select the F4 filter under the magnitude heading and set the probability range to 20 years.

Magnitude:

Click this filter to include and exclude specific Fujita magnitudes from the query. The color underneath each magnitude checkbox corresponds to the color coding in the visualization. For example, if you check F3, F4, and F5 and run the query, the map will visualize all counties which have experienced tornadoes of at least F3 intensity. A white colored country means that there have been no tornados matching the criteria to occur in that county. Orange means the county has experienced at least one F3 tornado, red means the county has experienced at least one F4 tornado, and purple means the county has experienced at least one F5 tornado.

Width:

Click this filter to specify the width of the tornados you wish to query for. Drag the dot icons on the range bar to modify the range. You can query for all tornados greater than width 'x' by setting the left dot to 'x' and the right dot all the way to the right. Conversely, to select tornados smaller than width 'x', you can set the right dot to x and the left dot all the way to the left.

Injuries:

Click this filter to return tornados that caused a specific quantity of injuries. You can query for all tornados resulting in more than 'x' injuries by setting the left dot to 'x' and the right dot all the way to the right. Conversely, to select tornados with fewer than 'x' injuries, you can set the right dot to x and the left dot all the way to the left.

Fatalities:

Click this filter to return tornados that resulted in a specific quantity of fatalities. You can query for all tornados resulting in more than 'x' fatalities by setting the left dot to 'x' and the right dot all the way to the right. Conversely, to select tornados with fewer than 'x' fatalities, you can set the right dot to x and the left dot all the way to the left.

Event time range:

Click this filter to query for a specific time range. Note: this will override the probability time range if it is set. You can query for all tornados that occurred after date'x' by setting the left dot to 'x' and the right dot all the way to the right. Conversely, to select tornados that occurred before date 'x', you can set the right dot to x and the left dot all the way to the left.

MAP LAYERS:

Show Tornado Tracks

Selecting this checkbox will display the travel path of each tornado returned from the query. Keep in mind that these paths are approximations based on the starting and ending longitude and lattitude coordinates.

Show State Borders

Check this box to outline the border of each state in the map.

Show past 24 hour data

If this box is selected, icons will appear on the map indicated live tornado warnings and alerts within the last 24 hours. Active warnings will appear in red, while expired warnings will appear in grey. Clicking an a warning icon will direct you to the detailed National Weather Service report for the event. Please remember if you are concerned that you may be under threat of an active tornado, consult your local weather station for more information. Do not use this website for weather updates if a tornado is currently on the ground or developing in your area.

SHARE:

This tab will reveal a weblink for your most recently executed search query. These links do not expire, so feel free to embed them in your own website if you wish.

LEGEND:

The legend will automatically update every time you run a search query, change the color code filter, or change the range calculator.