What are funnel clouds? 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.
How do funnel clouds 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.
What weather is associated with funnel clouds? Cumulonimbus clouds are almost always the host cloud from which the funnel clouds form, meaning that heavy rain, hail, thunder and lightning can all be expected. If a funnel cloud does make contact with the ground and produces a tornado, very strong winds can be expected in the immediate vicinity of the vortex potentially causing severe damage.
What is the difference between a funnel cloud and a tornado? Crucially, a funnel cloud does not reach the earth's surface, at the point it reaches land it becomes a tornado, or if it reaches a body of water it becomes a waterspout. In a typical year the UK sees around 30-35 tornadoes each year, though it is very rare that are they strong enough to cause any significant damage