Understanding Tornado Formation

• Tornadoes start subtly but escalate into powerful, destructive forces.

Tornado Formation and Classification

• Tornadoes are spinning columns of air connecting the ground to the clouds.
• Supercell tornadoes form within the most powerful thunderstorms (supercells).
• Non-supercell tornadoes are weaker, forming within non-supercell storms.
• A key factor in tornado formation is the presence of both high and low-pressure air.
• Air moves from high to low pressure areas, creating wind.
• Non-supercell tornadoes start with cool high-pressure air and warm low-pressure air near the ground.
• Winds at different speeds and directions create a cyclical flow.
• This flow turns into an upright spinning vortex in non-supercell tornadoes.
• Supercell storms draw warm, low-pressure air upward, leaving cool, high-pressure air near the ground.
• This creates a vertical wind that increases and forms a rolling pipe of wind.
• An updraft (upward current of wind) is essential for tornado creation.
• In non-supercell tornadoes, the updraft stretches the vortex to the clouds.
• In supercell tornadoes, the updraft lifts the rolling pipe of wind upright and pulls condensation into the vortex.
• Once the vortex connects the ground to the clouds, it is classified as a tornado.

Measuring Tornado Strength

• The Enhanced Fujita (EF) Scale rates tornadoes from EF0 to EF5.
• Ratings are based on damage caused and Doppler radar estimates of wind speeds.
• EF0 tornadoes have winds between 65 to 85 mph and are the weakest.
• EF5 tornadoes have winds exceeding 200 mph and are the strongest.

Tornado Occurrences

• Tornadoes occur on six of the seven continents.
• The United Kingdom has the most tornadoes relative to its land size (about 33 reported annually).
• The United States has the greatest overall number of tornadoes (over 1,000 reported annually).

Notable Tornado Events

• An EF5 tornado in Oklahoma City, Oklahoma, in 1999 had wind speeds over 300 mph.
• The Oklahoma City tornado resulted in 36 deaths, nearly 600 injuries, and $1 billion in damages.

Mitigation Efforts

• Tornadoes cannot be prevented, but communities are being protected.
• Meteorologists monitor storm fronts in high-risk areas to forecast potential tornadoes.
• Forecasting helps minimize damage and save lives.