Frequently Asked Questions
Where does the Tornado History Project get the historical tornado data?
All data comes from the Storm Prediction Center's (SPC) historical tornado data file, unless otherwise noted. Enhanced tornado path data for selected tornadoes comes from the National Climate Data Center (NCDC) (coming soon!)
How accurate is the data presented on this site?
The historical tornado data on this site is guaranteed to match the original source information (the SPC data), except where noted. However, the Tornado History Project can not guarantee the accuracy of the underlying SPC or NCDC data. If you believe an error had been made in the original data (number of fatalities is incorrect, approximate tornado path is wrong, etc...), please post a comment on the appropriate tornado details page.
How accurate are the tornado paths shown on the map?
The tornado path (or tornado touchdown point, if the path is unknown) is guaranteed to agree with the underlying source data (SPC or NCDC.) Even so, the tornado path or touchdown point as displayed on the map is generally an approximation only. There are several reasons for this:
- Latitude and longitude coordinates in the source data (SPC and NCDC) are given to 2 digits only. So, a tornado that actually touched
down at (33.5478, -101.9034) will be listed as (33.55, -101.90). This can introduce an error of roughly a couple of city blocks.
- Most latitude and longitude coordinates in the source data (SPC and NCDC) were estimated before the GPS era.
- Since a maximum of only two sets of coordinates are given (the touchdown and lift-off point) for most tornadoes, the resulting approximate
path must be drawn as a straight line. In reality, the actual path of the tornado between the touchdown and liftoff points can vary
significantly, particularly for longer paths. For tornadoes that have enhanced path data from the NCDC (coming soon!), this effect has been
diminished. However, path lines from any point to another can still only be drawn as straight lines.
- Although the path as drawn on the map is a thin line, the total width of the tornado's damage area could be significantly wider or narrower.
So, in the end, the tornado location and path as drawn on the map should be taken as approximate - sometimes it is dead on, sometimes it is not. If you see a tornado location or path that appears to be incorrect, please post a comment on the tornado details page.
How do I share my eyewitness account or post a link to a tornado photo or video?
Before you can share an eyewitness account, photo, or video, you first need to find the unique tornado details page for the tornado in question. To do this from a search in:
- Table view - Simply click the
icon to see the tornado information page. Once there, scroll down to the "Add a Comment" section.
- Map view - Simply click the tornado on the map, which will insert the tornado index number in the "Tornado Details" section on the left side of the page, then click "Go". Once there, scroll down to the "Add a Comment" section.
How do I share my tornado photos or videos?
If you have a tornado video or photo that you would like to share, please contact the Tornado History Project.
How can I link to the Tornado History Project from my web page or blog?
If you know HTML, feel free to write your own code. If not, you can use one of the following:
<a href='http://www.tornadohistoryproject.com'>Tornado History Project</a>
<a href='http://www.tornadohistoryproject.com'>tornado database</a>
<a href='http://www.tornadohistoryproject.com'>tornado map</a>
<a href='http://www.tornadohistoryproject.com'>tornado paths</a>