[Thunder.Net Communications]

Thunder & Lightning: Resources and Links

Provided as a public service by Thunder.Net Communications

We commonly get asked for links about thunder and lightning by children in school researching reports on weather and meteorology. We believe they come to us because they simply enter "thunder" into their web browser and it takes them to thunder.com.

While we're willing to help by posting some info and links, please be aware that is not the best way to perform research on the Internet. You should enter search terms into a web search engine. Some good ones for children are Google and Yahoo.

So here are some links and information about thunder and lightning which we hope you'll find helpful.

Facts about thunderstorms

Lightning can and often does strike the same place twice.
The electrical forces tend to prefer tall or metallic objects, especially if they aren't well grounded. While a storm is in progress, there's nothing to stop a positive charge from collecting in the same place it did before.

Thunderstorms can occur anywhere on Earth
The atmospheric conditions to form a thunderstorm can occur anywhere on Earth. Sometimes you may hear someone say "we don't get thunderstorms here." (This myth is common in coastal cities on the US West Coast.) Usually that means that they don't know how to recognize a thunderstorm without seeing lightning. Many people don't.

Lightning Safety

Lightning Safety at the Weather Channel
Safety info and tips.
Thunderstorms by the US Federal Emergency Management Agency
Information about lightning safety for kids.
Lightning Kills, Play It Safe at the US National Weather Service
Information about lightning and its dangers.
Lightning Safety for Kids by Sabrina (girl who was struck by lightning)

Lightning Photography and Stories

Lightning and Severe Weather Photography by Douglas "Lightning Boy" Kiesling
Photographs of lightning and tips for your own photography.
Lightning Strikes My Backyard by Ian Kluft
Lessons learned and photos of the tree branch removal after a lightning strike in San Jose, California on Sept 9, 1999.
ozthunder.com - Australian Weather and Storm Chasing
Storm chasing diaries, photos and info from Australia by Michael Thompson

Lightning-mapping Projects

National Lightning Detection Network
Map plot of automatically-detected lightning across the US
New Mexico Tech 3D Lightning Mapping System
3-dimensional lightning mapping research system

[picture] Cumulonimbus clouds at sunset over the North Atlantic Ocean. (select to download: 1536x1002 728K)

Lightning in the Upper Atmosphere: Sprites, Blue Jets & Elves

General Info on Thunder and Lightning

How does a thunderstorm form?

A thunderstorm always starts from a cumulus cloud. Though not all cumulus clouds grow into thunderstorms. A cumulus cloud can be recognized for its cotton-like puffy shape.

If the conditions are right, the cloud begins to grow upward. More about the "right conditions" will be mentioned below.

In this growing stage, the cumulus cloud can become very tall. People refer to this stage as a "towering cumulus", which means the cloud will become a thunderstorm soon.

You can easily tell if a cumulus cloud is growing upward. If the tops of the clouds are jagged in shape, they are not growing. But if the tops of the clouds change to curved shapes, they have begun growing upward. (If you see this from on top of a mountain, that's the time to start getting off the mountain.)

About the time that the first wispy-shaped and icy cirrus clouds form at the top of the towering cumulus, the first lightning can occur in the cloud. It won't necessarily be a bolt that strikes the ground. But at this point it's a thunderstorm.

Once it starts rain from the cloud, we call it a "cumulonimbus" cloud. That's because any cloud which produces rain has "nimbus" in its name.

In the final stage of a thunderstorm's life cycle, the rain and downdrafts take all the moisture out of the clouds. It basically rains itself out. The storm dissipates from the bottom up.
Under what conditions does a thunderstorm form?

If these "ingredients" are present together in the atmosphere, a thunderstorm will form.

The clouds need moisture to form in the first place. The more moisture available in the air, the more clouds can form.
The air usually gets cooler as you go up in altitude - you can easily see this when you travel up a mountain and the air is cooler than in nearby valleys. But the rate that it gets cooler isn't always the same.

When warm air rises, it cools. But if it's still warmer than the air around it, it can keep rising. This is called unstable air. It can keep rising until it reaches an altitude where the air is stable.

With the other ingredients in place, anything that makes air rise will start the growth of a thunderstorm. Warmth from sunlight shining on the ground can do it. So can wind blowing up a mountainside. Turbulent winds ahead of or behind a weather front can cause uplift. Even smoke from a large fire can start this process.

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