This is the moment people in the Cornish seaside town of Fowey knew the weather was about to turn - a funnel cloud appearing out to sea, just before the heavens opened and a deluge flooded the town.
Stunned onlookers spotted the cloud formation and feared it was a tornado coming in onto the south Cornish coast, as storm clouds rolled in when the heatwave broke in the far south west on Monday.
Soon the streets were ankle-deep with heavy rain as water poured off the dry hills and into the frequently-flooded coastal town.
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But as a precursor to the downpour, the unusual sight out to sea gave people warning the storm would be intense.
Stunned onlookers told CornwallLive how the cloud formation appeared, seemed to be spinning, before dissipating.
The formation was not a tornado, however. A whirlwind like this, descending from storm clouds, is only a tornado if the base touches the ground and continues. If it is over water, and the base touches water, it's a waterspout. But a formation that emerges from the base of a cloud but doesn't touch the surface of the Earth is a funnelcloud.
The Met Office explains: "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.
"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."
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