Question 1 of 15
Which scale rates tornado intensity in the United States?
Why: The EF Scale replaced the original Fujita Scale in 2007 and rates tornadoes EF0 through EF5 from damage evidence.
Question 2 of 15
What is the highest rating on the Enhanced Fujita Scale?
Why: EF5 is the top rating, assigned for incredible damage with estimated winds above about 200 mph.
Question 3 of 15
The EF Scale estimates wind speed primarily from what?
Why: Surveyors match observed damage to 28 damage indicators, then infer the wind speed that most likely caused it.
Question 4 of 15
Roughly what share of US tornadoes are rated EF0 or EF1?
Why: The large majority of tornadoes are weak. Violent EF4 and EF5 tornadoes are well under one percent of the total.
Question 5 of 15
Which state records the most tornadoes per year on average?
Why: Texas leads in raw annual count, largely because it is so big. Per unit area, Kansas and Oklahoma rank higher.
Question 6 of 15
A tornado WATCH means what?
Why: A watch means stay alert and be ready. A WARNING means a tornado is occurring or imminent and you should shelter now.
Question 7 of 15
Where should you shelter in a house with no basement?
Why: Put as many walls between you and the outside as possible, and get low. Bathrooms, closets, and hallways work well.
Question 8 of 15
Should you open windows to equalize pressure before a tornado?
Why: Houses do not explode from pressure differences. Opening windows wastes precious seconds and can let damaging wind inside.
Question 9 of 15
What is the fastest wind speed ever measured in a tornado?
Why: Mobile Doppler radar measured roughly 300 mph in the Bridge Creek-Moore, Oklahoma tornado of May 3, 1999.
Question 10 of 15
What is a mesocyclone?
Why: The mesocyclone is the deep, persistent rotating updraft that most strong tornadoes descend from.
Question 11 of 15
The deadliest single tornado in US history occurred in which year?
Why: The Tri-State Tornado of March 18, 1925 crossed Missouri, Illinois, and Indiana and killed roughly 695 people.
Question 12 of 15
Which direction do most US tornadoes travel?
Why: Steering winds usually push storms from southwest toward northeast, though individual tornadoes can turn any direction.
Question 13 of 15
What is a landspout?
Why: Landspouts form from surface rotation stretched upward by a growing cumulus cloud, not from a supercell mesocyclone.
Question 14 of 15
Is an overpass a safe place to shelter from a tornado?
Why: Overpasses accelerate wind and expose you to debris. If caught outside, lie flat in a low ditch away from vehicles.
Question 15 of 15
What does the 'Dixie Alley' term describe?
Why: Dixie Alley covers the Deep South, where tornadoes are often rain-wrapped, fast-moving, and strike at night.