Waterspout forms over Bristol Channel near Portishead

A waterspout formed over the Bristol Channel near Portishead during a thunderstorm at the weekend.

The rare event was spotted by weather enthusiasts on 16 August at around 4pm.

Pictures posted on social media show the funnel forming among dark grey clouds.

Russ Turner, who witnessed it, described the event as “exciting”.

What is a funnel cloud?

According to the Met Office, a funnel cloud is a cone-shaped cloud which extends from the base of a cloud towards the ground without actually reaching the surface. 

In the UK they often look like thin dangling bits of rope, hanging from the cloud above. 

• Flash floods and 'tornadoes' as thunder and lightning hits the West Country

But in hotspots such as tornado alley in the USA, funnel clouds can sometimes be thicker and much more intense.

Funnel clouds become tornadoes if they reach the ground, and waterspouts if they form over water.

How do they form?

A rotating column of wind draws in cloud droplets, making a region of intense low pressure visible. 

They are formed in the same way as a tornado, building around this localised area of intensely low pressure and are typically associated with the formation of cumulonimbus thunderclouds.

Read more:

• Severe storms cause disruption as weather warnings remain in place

• Torrential thunderstorms wreak havoc in the West Country as Met Office issues five-day weather warning

• Are we going to see thunderstorms across the West Country this week?