Lightning strike - Wikipedia
How to calculate the distance from a lightning strike.
Spreadsheet calculating the distance to a lightning strike.
How far is a lightning? - EEWeb
US National Weather Service Riverton Wyoming - You can estimate the distance lightning is from you using the “flash to bang” method. Here some other lightning tips.
Lightning Distance Calculator - 101 Computing
Lightning travels much faster than thunder, so you see lightning before you hear thunder. If you count 5
Counting Down Thunder: How Far Away Was That Lightning?
10 striking facts about lightning - Met Office
This equation will help keep you safer in storm season
How to calculate how far away lightning is by counting seconds
How to calculate thunder's distance - Quora
Thunderstorm - Lightning, Hail, Wind