Tornadoes Ashley Sacchetti MAIN MENU

Main Menu What is a Tornado? What is a Supercell? How They Form Warning Signs Tornado Measurement EF-0 & EF-1 EF-2 & EF-3 EF-4 & EF-5 Take the Quiz! History

What is a Tornado? A tornado, or twister, is a violently rotating column of air that extends between the Earth’s surface and a cumulonimbus cloud. Most tornadoes last for less than ten minutes according to Harold Brooks from the National Severe Storms Laboratory in Norman, Oklahoma. Most tornadoes have wind speeds less than 110 miles per hour and are about 250 feet across. Most tornadoes only travel a few miles before dissipating. MAIN MENU

Supercell Thunderstorm A supercells are usually thunderstorms, that contain wind updrafts that rotate. They rotate when there is a change in wind direction, and an increase in speed. Supercells produce large hail, damaging winds and tornadoes. Most strong tornadoes are associated with supercell thunderstorms. MAIN MENU

How They Form Though there are many types of tornadoes, they all form from a type of rotating storm called a supercell thunderstorm. Listed in the diagram are the steps at which a tornado forms. MAIN MENU

Signs There Might be a Tornado: Dark, often green colored sky Large hail A Large, dark, low cloud Loud roar, similar to that of a freight train MAIN MENU

Tornado Classifications: EF Sacle The original Fujita scale is named after Dr. Fred Fujita, a University of Chicago severe storms research scientist, who came up with the scale in 1971. The EF Scale is the spectrum at which a tornado is classified. The EF Scale ranges from EF-0 to EF-5 In the following slides, each type of tornado classification will be discussed. MAIN MENU

EF-0 Tornado EF-1 Tornado Ef-0 Tornadoes travel at a wind speed of 65-85 MPH. These tornadoes cause light damage: branches broken and some trees blown over. Travels anywhere from 73-112 MPH Moderate damage: moving cars, mobile homes overturned or pushed off their foundations. MAIN MENU

EF-2 Tornado EF-3 Tornado Travels anywhere between 113-135 MPH Considerable damage: mobile homes destroyed, large trees snapped or unrooted, cars lifted off the ground. 158-206 MPH Severe damage: Trains overturned, most trees uprooted, heavy cars thrown, homes destroyed. MAIN MENU

EF-4 Tornado EF-5 Tornado MPH ranging from 207-260 Devastating damage: well constructed buildings destroyed, large objects thrown. 261-318 MPH Incredible damage: cars thrown more than 100 meters, strong buildings swept away. MAIN MENU

Worst Tornado in History The “Tri-State Tornado” Traveled more than 300 miles through Missouri, Illinois and Indiana on March 18, 1925. Deadliest tornado in US history with 695 people killed and 2,027 injured. Rated an F5, under the old Fujita Scale Winds of 260+ MPH MAIN MENU

Test Your Knowledge: What type of tornado (using EF Scale) causes considerable damage by destroying mobile homes and uprooting trees? A. EF0 B. EF1 C. EF2 D. EF3 MAIN MENU

Incorrect! Sorry, but EF-0 is incorrect because it only causes light damage: branches broken and some trees blown over. Back to Quiz

Incorrect! Sorry, but EF-1 is incorrect because it causes Moderate damage: moving cars, mobile homes overturned or pushed off their foundations. Back to Quiz

Correct! Congratulations! EF-2 is the correct answer! Back to Quiz

Incorrect! EF-3 is incorrect because it causes devastating damage: well constructed buildings destroyed, large objects thrown. Back to Quiz

Congratulations! You’ve reached the end of the lesson! MAIN MENU