Lightning kills more people each year than tornadoes and hurricanes COMBINED. Thunder is the sound wave that occurs when air expands rapidly due to the extreme heat of a lightning flash.

Use the mouse to position the person further (or closer) from the base of the storm.

One way to estimate thunderstorm distance involves counting the seconds between a flash of lightning and the clap of thunder. Divide the number you get by 5 to estimate the distance (in miles) to the thunderstorm. Be sure to take cover if the storm is getting closer.

This applet is Copyright © 2011 by the American Meteorological Society.
This applet was developed by Ira Geer (AMS), Robert Weinbeck (AMS), and Tom Whittaker (University of Wisconsin-Madison).