Guests were then forced to clutch onto the remaining tents and shelters in a desperate bid to stop them being blown away.The bouncy castle later crashed down in the village hall car park.
Show chairman Trish Hunters described the incident as ‘pandemonium’.
‘The bouncy castle was there – and then it wasn’t,’ she said.
‘It came down the showground, picked up bits of marquee and caused damage. It plunged the bouncy castle slide 30ft into the air – the castle went across the road before coming down in the village hall car park.’
The funnel cloud hit just minutes after a scheduled flypast from a World War Two Spitfire from RAF Coningsby.
Emergency services, including the fire brigade and first aiders, rushed to the scene but noone was injured.
Mrs Hunter said: ‘The Spitfire flew over five minutes before. The pilot rang me once he was back in Coningsy and I told him we had just had a tornado. He was absolutely gobsmacked.
The damaged stalls did pack up but everybody has been supportive and the event carried on as planned with people enjoying themselves.’
One van was left with a smashed window after the metal stake went through it while the community radio station, County Linx Radio, suffered £500 worth of damage to its radio bus and speakers.
Radio co-founder Doug Lunn said: ‘We have lost a window and our canopy. It was an extremely scary 45 seconds.
‘We were holding on to the canopy for dear life but the twister just took it. It was just far too strong and one of our windows went too. It also damaged a pair of speakers.
Replacing what has been damaged is going to cost a fortune – the canopy on its own is going to cost around £500 to replace.’
The shocking images were taken by photographer Stephen Willmer.
Mr Willmer, 56, said: ‘The rain was coming down quite forcefully and we had a fly past from a Spitfire and the funnel came from the same direction.
‘It was only a matter of seconds but the inflatable slide flew well in excess of 30 feet high in the air.
‘People were holding onto marquees and children were screaming. I looked in the sky and saw three or four other funnels in the sky. It was very surreal and I would be surprised if I saw anything like it again.’
Fran Bates tweeted: ‘A twister hit Friskney Show and blew the bouncy castle into a tree and over the road. At least the two kids made it off.’
The Met Office has since confirmed the incident was caused by a funnel cloud. It is one of several twister-style storms which have been filmed in towns and villages in Lincolnshire last month. Tornadoes are caused by warm air and cold air colliding during storms.
University of Manchester scientists put together a map of UK tornado strikes, finding that the Thames Valley is the most likely area in Britain to be hit. One van was left with a smashed window while the community radio station, County Linx Radio, suffered damage to its radio bus and speakers.
Photo Credit: Stephen Willmer
Daily Mail: By Steph Cockroft for MailOnline
Published: 03:58 EST, 13 June 2016 | Updated: 06:29 EST, 13 June 2016
