Measuring the strength of a tornado can be difficult based on sight alone, and weather instruments could easily be damaged by the strong winds.
The Enhanced Fujita scale (EF-Scale) looks at the damage caused by a tornado to measure its strength.
The EF-Scale ranges from 0-5. EF-0 to EF-1 tornadoes cause light to moderate damage, breaking windows and branches, according to AccuWeather.
EF-2 to EF-3 tornadoes can cause roofs to be torn off houses and cars and trains to be lifted and overturned.
EF-4 to EF-5 tornadoes are the most severe. According to AccuWeather, entire neighborhoods can be leveled and cars can be thrown up to 300 feet by these twisters.
What is the EF-Scale?