A series of tornadoes has struck communities across England, damaging homes and vehicles and uprooting trees.
The Met Office confirmed that a squall hit Northampton, where falling branches damaged an empty school bus.
It also said that a violent storm damaged gardens and homes in Luton. Part of a factory roof was blown off in Breaston, Derbyshire.
Also affected were Farnborough, Hants, and Nuneaton, Warks. There have been no immediate reports of injuries.
Nina Ridge from the BBC Weather Centre said that the winds reached 60mph.
In a statement, the Met Office said that the gusts were "conducive to tornadoes" and measured T2 or T3 on the TORRO scale (which ranges from 0 to 10), meaning they were "moderate to strong".
It added that in Luton a violent storm hit at 0700 BST, damaging gardens and ripping tiles off house roofs.
Ruth Spaull of Luton said that she saw "a funnel of wind" lift her daughter's trampoline 15ft (4.52m) into the air.
According to the fire service, 20 houses were hit in Farnborough, Hampshire, at 0800 BST, tearing away a garage roof and uprooting trees.
Terry Parrott, who lives in Farnborough, said he looked out of his window to see a "complete whirling mass".
He added: "Caravans have been upside down, trees uprooted, bus shelters destroyed. It's just complete devastation."
Tim Vile, incident commander for Hampshire Fire and Rescue, said the area looked "like a battle-zone".
Terrence Meaden, deputy head of tornado research group TORRO, said five reports were "looking certain" to be confirmed as tornadoes.
And he said further research could show another five cases of similar conditions, in places such as Northampton, Scunthorpe and Ollerton in Nottinghamshire, were tornadoes.
Dr Meaden said such a series was "infrequent enough" but not unprecedented.
Northampton resident Andy Summerville told BBC News 24 that the sky went "completely black" at around 0710 before tiles were blown onto parked cars.
Winds damaged around 20 homes in Trafford Drive, Nuneaton, with tiles pulled from roofs, cars smashed and debris scattered across the streets, Warwickshire Police said.
The local borough council said 35 homes were damaged in the Mallard Avenue and Kingfisher Way area.
Lollipop lady Beryl Warburton, 79, who lives on Trafford Drive, said the "frightening" storm struck at about 0615.
She said: "Some of the houses have had their roofs taken off completely, some have lost parts of their roofs."
Cambridgeshire Police said a motorist reported seeing a car blown across a road by a "tornado" in the village of Eye.
TORRO claims an average of 33 tornadoes are reported annually in the UK.
Dr Meaden added that the weather system which caused the tornadoes was over Exeter, Devon, at 0400 BST and travelled eastwards before passing out into the North Sea by around 0900 BST.
The Association of British Insurers (ABI) said it was too early to say how many people had been affected by the tornadoes.
Insurance claims for the tornado that swept through London in December 2006, in which around 100 properties were damaged, cost the industry £350,000.
The ABI estimated Monday's storms were likely to cost less than this figure.