Tornado

A tornado is a rotating column of air, extending from the base of a cumuliform cloud, and often visible as a condensation funnel in contact with the ground, and/or attendant circulating dust or debris at the ground (WMO, 2017).

The strength of a tornado can be estimated from the degree of damage caused using the Enhanced Fujita scale (Wind Science and Engineering Center, 2004; National Weather Service, no date).

Tornadoes kill fewer than 100 per year on average but they can be very destructive and cause huge economic losses. The United States is a major hotspot with about 1,000 tornadoes every year, causing 80 deaths and more than 1,500 injuries on average (National Geographic, 2019).

Owing to the unpredictable nature of tornados, protecting the public is focused on education and outreach which provide information on the tornado as a threat, how to identify a tornado and practical measures on how individuals can protect themselves, and how to find and watch warning systems that alert the public (CDC, 2020).

Since the advent of Doppler Radar, lead times for tornado warnings have increased from when a tornado first touches the ground to upwards of 14 to 20 minutes or more beforehand (WMO, 2017b; National Geographic, 2019).

Risk factors

  • Lack of early warning systems and preparedness programmes.
  • Even when warning systems are in place, the aged and children have higher mortality rates.
  • Populations living in mobile homes are at greater tornado risk. The rate of serious injury for mobile homes occupants is 85.1 per 1,000 compared to 3 per 1,000 for occupants in standard homes.

Vulnerable areas

  • The most tornado-prone areas in the world are in North America, in particular the Great Plains in the United States and south-central Canada.
  • Tornado Alley, a region that includes eastern South Dakota, Nebraska, Kansas, Oklahoma, northern Texas and eastern Colorado, is home to the most powerful and destructive of these storms.
  • The United States gets 75 per cent of all the world’s tornadoes, followed by Canada and Bangladesh.
  • Australia, New Zealand, South Africa, India, Argentina and the Russian Federation are also prone to strong tornadoes.
  • Communities living in poorly built houses close to potential flying objects are in particular danger. People outdoors when tornadoes occur are at higher risk of mortality.

The Enhanced Fujita Tornado Scale

The Fujita Scale is named for Dr TT (Ted) Fujita, who made the first systematic study of tornado forces; it was replaced by the Enhanced Fujita (EF) Scale in February 2007.

Risk reduction measures

  • Monitoring systems to observe thunderstorms with radar and receive reports on tornadoes.
  • A hazard map to identify risk and vulnerability.
  • A warning/communication system to alert people in the path of a tornado.
  • Underground shelters to protect people.
  • Avoiding mobile home settlements in risky zones.
  • Education and awareness about tornadoes, warnings and safe action.

Latest Tornado additions in the Knowledge Base

Haiti aerial view
As odd as it may sound, an earthquake, a tropical storm, an epidemic outbreak, and a cyber-attack occurred in Panama in June 2023 as the scenario for an emergency drill.
World Bank, the
Severe storms account for nearly half (48%) of all billion-dollar weather disasters in the U.S. since 1980. The frequency of favorable tornado days (indicated by daily maximum significant tornado parameter values) has increased significantly.
Climate Central
The storm and tornado outbreak that recently barreled through the US Midwest, South and Mid-Atlantic was a devastating reminder of how much danger spring can deliver, despite it being the “milder” season compared to summer and winter.
Union of Concerned Scientists
Tornado in Colorado, USA
Meteorologists have gotten a lot better at forecasting the conditions that make tornadoes more likely. But predicting exactly which thunderstorms will produce a tornado and when is harder, and that’s where a lot of severe weather research is focused today
Texas A&M University System
Warm weather is a key ingredient in tornadoes and climate change is altering the environment in which these kinds of storms form. But the research into the link between climate and tornadoes still lags behind that of other extreme weather events.
NPR
Cover
2023
This study used extreme value theory to estimate the impact of tornado outbreaks on fatalities while accounting for climate and demographic factors.
International Journal of Disaster Risk Science
Cover IJDRR
2023
This study test the ability of negative binomial regression models to predict tornado-induced injuries and fatalities by coupling data on physical characteristics of tornadoes, exposure of populations, and underlying social vulnerability.
International Journal of Disaster Risk Reduction (Elsevier)
Cover EGU
2022
This paper seeks to answer the question whether climate change may have affected the characteristics of a specific extreme event or whether such event would have even been possible in the absence of climate change.
European Geosciences Union