When a twister came to Selly Oak

THE RESIDENTS of Wellman Croft in Selly Oak, Birmingham were a bit lost for words yesterday. As one woman, staring at her bedding plants - now in next door's back garden - explained: "Last week we were watching on the television how tornadoes wrecked Oklahoma. Then suddenly there's a tornado coming down our street."

She was one of hundreds caught up in the strongest "twister" or mini- tornado to have hit Britain in 18 months, on Monday. The freak weather also hit Grantham in Lincolnshire, Rugeley in Staffordshire and Upavon in Wiltshire, but its worst was saved for the West Midlands, where a twister flooded homes and knocked down power and telephone lines with 90-110mph winds.

In Grantham, where 4,000 people were left without electricity, the twister could be seen three miles away in jet black skies by people who stood in brilliant sunshine.

In Wolverhampton, the emergency services used dinghies to evacuate more than 100 families from their houses as four feet of water flooded part of the town. At one stage, Cannock was described by police as being "like an island", with 700 people effectively cut off by flash floods. Staffordshire Ambulance Service's non-emergency phone lines were knocked out and thousands of homes lost power.

In Birmingham, the 150ft high column that whistled upWellman Croft and damaged at least 21 homes in the cul-de-sac could only be seen by the bin bags, fencing, leaves and plants it was pulling up, according to one of the residents, Geoff Turford. "I was sat in the back window and I thought it was going to break," said Mr Turford, 76. "The next thing I saw was a dustbin bag come up from the street and fly past the window like a kite. Then the branches of trees started bending ... you could see where it was going by the debris it was pulling up into the air."

At David Oakley's house, partially covered by a green tarpaulin as he mopped up yesterday, pictures crashed from walls before a large hole was torn in his roof.

The tornado was at least as powerful as Britain's last twister at Selsey, West Sussex, in January last year which had wind speeds of 100mph and was a quarter of a mile wide. It caused pounds 2m worth of damage. However, compared with the mile-wide tornado which hit Oklahoma and Kansas earlier this year, it was a breeze. Wind speeds in the American storm reached 250mph, leaving at least 34 people dead and more than 1,000 homes destroyed in Oklahoma City alone.

There are 33 tornadoes on average in Britain every year according to Terence Meaden at the UK's Tornado and Storm Research Organisation. "There were nine on 14 May," he said, "but after the BBC's Twister Week on television last week a lot of people have been alerted who would not realise what they were seeing."

Tornadoes occur when warm air masses and cold air masses collide over land. As humid air spirals up to meet cool air, it is replaced by air which is sucked in faster and faster until the whole mass is rotating furiously - and causing damage.