A "significant tornado" hit eastern parts of Jersey during Storm Ciarán, the Tornado and Storm Research Organisation (Torro) has confirmed.
The storm hit Jersey on Thursday, displacing more than 150 residents and causing major damage to homes, organisations and schools. Torro said it conducted an in-person site investigation alongside Jersey Met at the weekend, finding a tornado had passed through St Clement at about 00:00 GMT on Wednesday.
It said "severe damage" was found along the length of the 8km (4.9-mile) track, exiting the island around Fliquet. The organisation, which keeps records of tornadoes for the UK, Republic of Ireland, the Channel Islands and the Isle of Man, said it was currently putting the intensity of the tornado, external on the Beaufort wind scale at T6.
Its website said that that intensity classed it as a "moderately-devastating tornado", capable of reaching speeds of up to 161-186mph, or 7.3-8.3m per second. It said there had "only been a few tornadoes of T6 intensity and greater in the last century within the records".
The one in Jersey was "likely the strongest" since one in Gunnersbury, west London, in December 1954, which was rated T7, it said.