Tornado Formation and Geography

• Tornadoes are violently rotating columns of air formed during thunderstorms with wind speeds up to 250 mph.
• The word "tornado" comes from the Spanish word "tornar," meaning "to turn."
• Tornadoes are also known as twisters, cyclones, or funnel clouds.
• Tornadoes most commonly occur in southern Canada and "Tornado Alley" in the United States.
• "Tornado Alley" includes South Dakota, Nebraska, Kansas, Oklahoma, northern Texas, and eastern Colorado.
• The Great Plains and Florida are prone to tornadoes due to frequent thunderstorms.

Tornado Formation

• Tornadoes usually form in late spring and summer when conditions favor supercell formation and updrafts.
• A supercell is a large thunderstorm with rotating winds, occurring in about 1 in 1000 storms.
• Supercells produce tornadoes approximately 20% of the time.
• Varying wind speeds at different altitudes during thunderstorms may lead to tornado formation.
• Vertical wind shear during supercell formation can produce a horizontally rotating air column.
• Updrafts lift the rotating air column, causing it to narrow and spin faster, forming a funnel cloud.
• A funnel cloud becomes a tornado when it touches both the ground and the source cloud.
• Doppler radar detects hook echoes, bends in radar signals, providing about 10 minutes' warning of a tornado.

Tornado Effects

• Tornadoes can be over 660 feet wide and typically travel less than six miles.
• Tornadoes cause widespread destruction and loss of life due to high wind speeds.
• Tornadoes cause approximately $400 million in damage annually in the US.
• Around 70 people die each year due to tornadoes.
• Tornadoes damage the environment by destroying forests and wildlife habitats.
• Wind-damaged forests are more susceptible to non-native plant species invasion, slowing recovery and impacting neighboring habitats.

Categorizing Tornadoes

• Meteorologists use Doppler radar and computer modeling to predict tornadic activity.
• Hook echoes identify areas of rotation within thunderstorms, aiding public warnings.
• Storm chasers use equipment and weather balloons to measure factors involved in tornado formation.
• National Weather Service scientists assess damage to determine wind speed and path, assigning a number based on the Enhanced Fujita Scale.
• The Enhanced Fujita Scale evaluates damage to buildings and trees caused by specific wind speeds.
• The Enhanced Fujita Scale uses 28 damage indicators to assign a rating.
• Tornado size and path length correlate positively with destruction levels.
• Longer path length and increased width leads to greater tornado intensity.

Enhanced Fujita Scale

• Before 2007, the Fujita-Pearson (FPP) scale was used, based on damage types rather than wind speed.
• The Enhanced Fujita (EF) Scale, introduced in 2007, incorporates damage indicators and degrees of damage to reflect wind speeds.
• The lowest EF Scale number signifies a weak tornado, with strength increasing with higher numbers.
• EF0: 65-85 mph, broken tree branches, some shingles blown off.
• EF1: 86-110 mph, loss of exterior doors, many shingles blown off.
• EF2: 111-135 mph, roofs torn off homes, mobile homes destroyed.
• EF3: 136-165 mph, severe damage to large buildings, overturned trains and cars.
• EF4: 166-199 mph, whole houses leveled.
• EF5: 200-230 mph, houses swept away.

Explore the formation and geography of tornadoes. Tornadoes are violently rotating columns of air formed during thunderstorms, with the term originating from the Spanish word 'tornar.' They commonly occur in regions like 'Tornado Alley' in the United States, especially during late spring and summer.