"I'm very pleased to say there are no fatalities or injuries ... and actually only relatively minor reports of property damage, " he told CNN.

CNN: Tornadoes tear through Kansas, Oklahoma and Iowa

Adam Rose, an economist at the University of Southern California, prefers to include only direct costs such as business interruption and property damage.

WSJ: Bill for a Bombing Can Be Hard to Tally

It said it was receiving a high number of flood-related calls and, with more rain forecast, urged the public to call 999 only if there was a risk to life or risk of serious property or environmental damage.

BBC: Roads flooded after stormy night in Surrey and Sussex

Heathrow Airport says only one in 10, 000 flights result in vortices which can cause damage to property.

BBC: Vortex from plane landing at Heathrow damages roof