13K views · 345 reactions | Tornadoes occur on nearly every continent on Earth. Tornadoes form during thunderstorms, when warm moist air collides with cool dry air but will only form when the atmospheric conditions are just right. One of the great mysteries of science is why one storm will produce tornadoes and another won't. Watch Mutant Weather on Sundays at 7pm on National Geographic UK. | National Geographic UK | Facebook

220K views · 477 reactions | The tornado affected areas of Balsall Heath, Small Heath, Moseley, Sparkbrook and Kings Heath in Birmingham on 28 July 2005. | BBC Birmingham | Facebook

Today marks the 10th anniversary of The Birmingham Tornado - one of the worst ever to hit Britain. When it struck in 2005, no-one could have imagined the havoc it would wreak. In just four minutes, it caused an estimated 40 million pounds worth of damage and injured 20 people. For those affected, it's been a long road to recovery. So, 10 years on, what are their memories of that day and what impact has it had on their lives? | BBC Birmingham