CH 10 - Thunderstorms and Tornadoes

Thunderstorm

A storm that produces lightning and thunder, often accompanied by gusty winds, heavy rain, and hail.

Cumulonimbus Clouds

Tall, dark clouds associated with thunderstorms.

Air Mass Thunderstorms

Thunderstorms that usually form within air masses, particularly mT air masses from the Gulf of Mexico.

Severe Thunderstorm

A thunderstorm classified as severe if it has winds greater than 58 mph, produces hail larger than 1 inch, or generates a tornado.

Downdraft

A downward movement of air within a thunderstorm, which can weaken the updraft.

Mature Stage

The stage in a thunderstorm where updrafts and downdrafts are well developed, leading to precipitation.

Entrainment

The movement of cool dry air from outside the thunderstorm cloud into the cloud.

Gust Front

Outflow boundary of cool air from a downdraft, similar to a cold front.

Hail Formation

Occurs when ice particles move up and down in a cloud due to strong updrafts and downdrafts, growing in size.

Tornado

A small-scale storm in the form of a rotating column of air, capable of great destruction.

Tornado Alley

A region in the Great Plains and Midwest where tornadoes are most common.

Wind Shear

Change in speed or direction of winds with height, necessary for forming a mesocyclone.

Supercell

A single cell severe thunderstorm that can produce tornadoes or damaging hail.

Mesocyclone

A column of cyclonic rotating air that can develop into a tornado.

Enhanced Fujita Scale

A scale that rates tornadoes based on estimated wind speeds and damage caused.

Microburst

A strong localized zone of sinking air from a thunderstorm, which can cause significant damage.

Mammatus Clouds

Clouds that resemble downward bulging pouches and often indicate a severe thunderstorm.

Charge Separation

The process within a cloud that creates the conditions for lightning by separating positive and negative charges.

Thunder

The sound produced by the rapid expansion of air due to the heat of lightning.

TORCON Index

A scale from 0-10 quantifying the chance of a tornado occurring within a 50-mile area.

Dissipating Stage

The final stage of a thunderstorm when updrafts weaken, and the storm begins to dissipate.