Tornadoes

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Thunderstorm Noun

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[thun-der-storm]

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Thunderstorm

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A storm with lightning and thunder, produced by a cumulonimbus cloud and often featuring gusty winds and heavy rain.

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Example: This image shows that a thunderstorm is formed when three ingredients combine: moisture, warm unstable air, and a lifting mechanism.

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Tornado Noun

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[tor-nay-doh]

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Tornado

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A violently rotating column of air that extends from a thunderstorm to the ground, capable of causing immense destruction.

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Example: This diagram shows that a tornado's destructive power is greatest at its core, with wind speeds and damage decreasing with distance from the center.

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Twister Noun

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[twis-ter]

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Twister

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An alternative, colloquial name for a tornado, which is a violently spinning, funnel-shaped column of air.

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Example: This diagram shows how a tornado forms: wind shear creates horizontal rotation, and a storm's updraft lifts this rotation vertically, forming a spinning funnel.

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Cumulonimbus Clouds Noun

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[kyoo-myuh-loh-nim-buhs kloudz]

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Cumulonimbus Clouds

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Dense, towering vertical clouds associated with thunderstorms and atmospheric instability, from which tornadoes can form.

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Example: This diagram shows the development of cumulonimbus clouds, from a puffy stage to the mature, flat-topped "anvil" shape that can produce severe weather like tornadoes.

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Cold Front Noun

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[kohld fruhnt]

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Cold Front

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The boundary where a cold, dry air mass pushes over a warm, humid air mass, often causing thunderstorms.

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Example: This diagram shows a cold front, where a dense mass of cold air plows under a lighter warm air mass, forcing it to rise quickly.

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Updraft Noun

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[uhp-draft]

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Updraft

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A current of rising air within a thunderstorm, created when warm air rises through colder air, which can initiate rotation.

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Example: This diagram shows an updraft as a strong, rising current of warm air moving up into a large storm cloud, a key process in forming tornadoes.

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Funnel Cloud Noun

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[fuhn-l kloud]

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Funnel Cloud

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A rotating, cone-shaped column of air extending from the base of a thundercloud that has not yet touched the ground.

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Example: This image shows a funnel-shaped cloud extending down from a storm cloud, but it has not yet touched the ground, which is what defines it.

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Supercell Noun

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[soo-per-sel]

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Supercell

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A large, long-lasting, and rotating thunderstorm with a well-defined updraft, which is the most common producer of strong tornadoes.

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Example: This diagram shows a supercell, a powerful thunderstorm with a rotating updraft called a mesocyclone, which is the feature that can produce tornadoes.

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Fujita Scale (F-Scale) Noun

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[foo-jee-tuh skeyl]

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Fujita Scale (F-Scale)

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A scale used to classify tornado intensity based on the estimated wind speed and the resulting damage to structures and vegetation.

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Example: The Enhanced Fujita (EF) Scale rates tornado strength from EF-0 to EF-5 based on the level of damage caused to buildings and trees.

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Enhanced Fujita Scale (EF-Scale) Noun

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[en-hanst foo-jee-tuh skeyl]

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Enhanced Fujita Scale (EF-Scale)

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An updated tornado rating scale that uses a detailed list of damage indicators to provide more accurate wind speed estimates.

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Example: This chart shows the Enhanced Fujita (EF) Scale, which rates tornado intensity based on wind speed and the resulting damage, from minor to incredible.