What are cloud flashes? A cloud flash is lightning that occurs inside the cloud, travels from one part of a cloud to another, and some channels may extend into clear air. Is it possible to have thunder without lightning?
No, it is not possible to have thunder without lightning. Thunder starts as a shockwave from the explosively expanding lightning channel when a large current causes rapid heating. However, it is possible that you might see lightning and not hear the thunder because it was too far away. Is lightning always produced by a thunderstorm? Thunderstorms always have lightning thunder is caused by lightning, and you can't have a thunderstorm without thunder!
The expansion creates a shock wave that turns into a booming sound wave, known as thunder. As ice crystals high within a thunderstorm cloud flow up and down in the turbulent air, they crash into each other.
Small negatively charged particles called electrons are knocked off some ice and added to other ice as they crash past each other. The top of the cloud becomes positively charged while the base of the cloud becomes negatively charged.
Once the negative charge at the bottom of the cloud gets large enough, a flow of negative charge called a stepped leader rushes toward the Earth. The positive charges at the ground are attracted to the stepped leader, so positive charge flows upward from the ground. When the stepped leader and the positive charge meet, a strong electric current carries positive charge up into the cloud.
This electric current is known as the return stroke. We see it as the bright flash of a lightning bolt. Myth 1 — Lightning never strikes twice in the same place. The Empire State Building was once used as a lightning laboratory because it is hit nearly 25 times per year, and has been known to have been hit up to a dozen times during a single storm. Fact: Lightning is indiscriminate and it can find you anywhere. Lightning may hit the ground instead of a tree, cars instead of nearby telephone poles, and parking lots instead of buildings.
Fact: Sheltering under a tree is just about the worst thing you can do. Being underneath a tree is the second leading cause of lightning casualties. Fact: Lightning often strikes more than three miles from the thunderstorm, far outside the rain or even the thunderstorm cloud. Myth 5 — A car's rubber tires will protect you from lightning Fact: True, being in a car will likely protect you. But most vehicles are actually safe because the metal roof and sides divert lightning around you—the rubber tires have little to do with keeping you safe.
Convertibles, motorcycles, bikes, open shelled outdoor recreation vehicles and cars with plastic or fiberglass shells offer no lightning protection at all. Myth 6 — If you're outside in a storm, lie flat on the ground. Fact: Lying flat on the ground makes you more vulnerable to electrocution, not less.
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