Fujita scale
Following two particularly devastating tornadoes in 1997 and 1999, engineers questioned the reliability of the Fujita scale. Ultimately, a new scale was devised that took into account 28 different damage indicators; this became known as the Enhanced Fujita scale. With building design and structural integrity taken more into account, winds in an EF5 tornado were estimated to be in excess of . The Enhanced Fujita scale is used predominantly in North America. Most of Europe, on the other hand, uses the TORRO tornado intensity scale (or T-Scale), which ranks tornado intensity between T0 and T11; F5/EF5 tornadoes are approximately equivalent to high-end T9 to T11 on the T-Scale.