A mini-tornado is thought to have swept through a caravan park causing damage and smashing windows.
Tornadoes can strike at any time of the year
It struck on Monday night lifting a boat off a trailer and tearing awnings at Morfa caravan park in Llanrhystud, near Aberystwyth.
Holidaymaker Jason Jones, from Caerphilly, thought the roof of his caravan was "going to be ripped off".
A weather specialist said he was confident a weak tornado was responsible as damage was "localised".
Mr Jones, who was staying in a caravan with his wife and two children, said the strong winds blazed a path about 40ft wide at about 2230 BST on Monday.
He said: "It started raining heavily and then there was a rumbling sound that I'd never heard before.
"The caravan started shaking and the children were becoming quite scared so I told them to get into the back with their mother and get under a duvet.
"It was so bad that I thought we were either going to take off or the roof was going to be ripped off."
Mr Jones said the strong winds only lasted a "few seconds", but "wreaked havoc".
John Mason of Tornado and Storm Research Organisation (TORRO) visited the scene on Tuesday.
After speaking to the site owner and holidaymakers he said he was confident a weak tornado was responsible.
He said gusts would have reached about 70 or 80mph.
Morfa caravan park owner Enid Jones said the strong winds lifted a boat off a trailer and hurled it into a caravan awning. She said that some caravan windows were also broken.