A twister in the middle of London?
Today’s tornado in North West London was a medium-sized twister by British standards. Initial reports of the level of damage to trees, roofs and cars indicate wind speeds of around 100mph (160kph), a T3-T4 strength tornado, on a scale ranging from T0 to T10 developed by the Tornado and Storm Research Organisation (Torro).
In fact, Torro had issued a forecast alert of thunder, hail, lightning and tornado as conditions in the southern half of Britain turned convective. This meant that air was rising through the atmosphere – a surge of warm, moist tropical air rose up and hit colder drier air higher up, exploding into thunderclouds. This produced a squall line, a violent band of thunderclouds, which tore across Southern England during the morning.