By chance this storm happens to be one of those rare events and it's well documented

By chance this storm happens to be one of those rare events and it's well documented

Within straight-line winds, small differences in wind strength can generate small whirlwinds. In line with this, there is evidence of these whirlwinds in Utrecht.

Paintings of the destruction show that the nave of the Dom cathedral and some church towers toppled in a northerly direction – the way that the front was travelling – but others fell to the west, perpendicular to the direction of the front. They can only have been brought down by whirlwinds producing strong westerly gusts.

"So far, everything we have from the eyewitness accounts is in line with the hypothesis that this was a bow echo," says van der Schrier.

A bow echo over South Dakota (Credit: Mike Hollingshead/Alamy)

This sort of work has the potential to be valuable to the authorities in the Netherlands, says van der Schrier. They are keen to ensure that buildings and other structures are strong enough to withstand rare but severe storms