In the northwest US, a tornado has been captured moving over mountain peaks. But is that really possible?

In the town of Saint Ignatius in the US state of Montana, among the Rocky Mountains, residents have observed a low-hanging and rotating funnel cloud. It is still yet to be officially confirmed whether this was a tornado.

Funnel clouds are rotating, tapered cloud formations. Only once the vortex touches the ground, does it become a tornado. The images do not show whether it did however, and there is also no information regarding damage.

It's an age-old myth that people believe tornadoes cannot form in mountainous regions. However, the evidence proves otherwise.

In fact in the last five years there have been at least three documented tornadoes in mountain ranges in the US. Generally, the conditions for tornadoes to form are not ideal due to the orography, and indeed are far more common on flatter terrain.

However, recent research has also shown that storms coming down the sides of the mountains may actually enhance low-level rotation.

A potential tornado was also recently sighted in Hampshire, UK, amidst a barrage of thunderstorms.