Tornadoes

A tornado is a rapidly rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as twisters or cyclones. Tornadoes come in many shapes and sizes, but are typically in the form of a visible condensation funnel, whose narrow end touches the Earth and is often encircled by a cloud of debris and dust.

Formation

Tornadoes form from powerful thunderstorms. When warm, moist air collides with cool, dry air, it creates instability in the atmosphere, leading to the development of a rotating updraft. If the updraft is strong enough, it can create a mesocyclone, which is a rotating air mass within a supercell thunderstorm. When this mesocyclone tightens, it can form a tornado.

Characteristics

Tornadoes can vary in size, shape, and intensity. The Enhanced Fujita (EF) scale is used to categorize tornadoes based on the damage they cause, ranging from EF0 (weakest) to EF5 (strongest). Tornadoes can have wind speeds ranging from 65 mph (105 km/h) to over 200 mph (320 km/h).

Safety Precautions

• Have a designated safe area in your home such as a basement or storm shelter.
• If a tornado warning is issued, seek shelter immediately and stay away from windows.
• If caught outdoors, seek low-lying areas and cover your head and neck with your arms.

Study Guide

Here are some key points to remember when studying tornadoes:

1. What are the conditions that can lead to the formation of a tornado?
2. Describe the characteristics of a tornado and how they are categorized.
3. What safety precautions should be taken in the event of a tornado?
4. Research and describe a famous tornado event in history.