When the thunder first rumbles in the distance on a summer afternoon, those outside in their gardens, or perhaps shopping in the high street may cast a cursory glance skyward before continuing with their tasks.
Some may begin to hurry inside, perhaps packing the lawnmower or patio furniture away first.
Most people, though, will probably expect nothing more than a sharp shower of rain, a few flashes of lightning and rumbles of thunder before it dries up, and they can continue about their business.
This was not the case across the south-eastern suburbs of Birmingham on the afternoon of Thursday July 28, 2005.
On this day, a particularly strong thunderstorm developed to the south of the West Midlands, in an atmosphere extremely favourable for severe weather.
It went on to produce one of the strongest British tornadoes for a number of years, carving its path of destruction through parts of King's Heath, Small Heath and Sparkbrook.
Investigators from TORRO, the Tornado and Storm Research Organisation (www.torro.org.uk) measured a damage path over 11 km (7 miles) long, and up to 500 metres wide.
The tornado was also estimated to contain winds of up to 140mph. People who were out shopping on the Kings Heath High Street dashed for cover as the tornado tore off roofs, shattered windows, and turned debris into lethal missiles.
Miraculously no one was killed, but several people received severe injuries, and many buildings were damaged, some so severely that they still remain uninhabitable now.
TORRO has been investigating this tornado, and others which occurred on this day, over the last year.
It will be presenting the findings at a public conference tomorrow, at the University of Birmingham.
The presentations will identify what is thought to have caused the tornado, how it was predicted, and whether it could happen again.