thunder can be caused by cloud-to-ground lightning (NOAA)

What causes thunder?

Thunder is produced by lightning, which in turn is caused by thunderstorms. Lighting heats the narrow channel of air it occurs in to an extremely high temperature, which then causes a localized pocket of high air pressure. Since 'sound' is rapidly travelling waves of pressure in the air, this creates a traveling sound wave emanating outward from the lightning bolt, which we then perceive as thunder.

The sound of thunder is affected by numerous factors, for example, whether the lightning is cloud-to-ground (which typically causes a louder, booming sound), or cloud-to-cloud (which typically causes a less-loud, cracking sound). Some of the loudest thunder you will here will be from infrequently occurring positively charged bolts coming out of thunderstorm anvils after the heaviest raining part of the storm has passed.

If a lightning-producing storm is a great distance from you at night, you might be too far away to hear the thunder, which some people refer to as "heat lightning".

"Rolling" thunder is the echo of thunder off of other storm cells in your vicinity.

Lightning and thunder are more prevalent over land than over the ocean, because the sun heats land surfaces to higher temperatures, which leads to a more unstable airmass, which is the cause of thunderstorms. This is also why it is usually more dangerous for an airplane to fly through a small thunderstorm over land than it is to fly through a large hurricane over the ocean.
(page last updated 6/1/2012)
Like WeatherQuestions.com? Try our weather:
WeatherStreet.com home
enter ZIP CODE or CITY, STATE or STATE
WeatherQuestions.com is a service of WeatherStreet.com
Copyright © 2013 WeatherStreet.com