Just how common are tornadoes in Europe?

A rare tornado in southwestern Luxembourg late on Friday injured 19 people, two of them severely.

The tornado struck the communities of Pettingen and Kaerjeng, near the border with France and Belgium, leaving a path of destruction that destroyed some 100 houses.

Debris and damaged cars were strewn around the area, while at least four electric poles were also destroyed.

A spokesperson for Luxembourg police reported a “swath of desolation” spanning up to six kilometres. The country’s rescue centre said cleanup would take days. Emergency shelters have been set up for those who lost their homes.

On the same day, a tornado swept through Amsterdam’s Oosterdok Basin, in the Netherlands, as storms hit the region. No injuries were reported and the damage was minimal.

Tornadoes are less common in Europe than in the United States, where Tornado Alley in the Midwest experiences hundreds every year. So far this year, there have been 1,300 confirmed tornadoes in the US.

While Europe’s tornado touchdowns are not as frequent, every year between 200 and 400 occurrences are reported. Italy and Greece see more tornado activity, as the warm, moist Mediterranean air clashes with the cool, dryer air over the mountains.

Tornadoes are vertical funnels of rapidly spinning air, developing in thunderstorms and often accompanied by hail. The violently rotating column of air extends from the thunderstorm down to the ground. Once the tornado hits the ground, it may last for as little as a few seconds, or as long as three hours.

Tornadoes in West Europe are a bit more unusual, but can happen, as we saw on Friday.

The United Kingdom also sees a high number of tornadoes, averaging between 30 and 50 each year. That is more tornadoes average land area than anywhere in the world, apart from the Netherlands.

In 2015, scientists at the University of Manchester mapped the UK’s tornadoes and estimated that the area from Berkshire into London had the highest likelihood of a tornado – one every 17 years.

Most tornadoes that develop across Europe have much less damaging effect than those in the US, but Luxembourg on Friday was one exception, as was the case in 2005 in Birmingham in the UK.

The 2005 tornado lasted for approximately 10 minutes, with wind speeds up to 233km/h. It uprooted about 1,000 trees, injured 19 people and caused damage of around 40 million British pounds ($49m).