[1] It is used by the European Severe Storms Laboratory (ESSL) and various other organizations including Deutscher Wetterdienst (DWD) and State Meteorological Agency (AEMET).
Most notably, the 2021 South Moravia tornado received a rating (IF4) and full damage survey on the IF-scale conducted by ESSL, the Czech Hydrometeorological Institute and four other organizations.
[4] The 12 categories for the International Fujita scale are listed below, in order of increasing intensity.
The errors have been estimated to be 30% of the central value, resulting in overlapping speed ranges.
It was noted that each scale's wind speed is to be taken with a 20% error margin on each side of the central value.
For the IF scale, only wind speeds measured at or below 10 metres (11 yd) can be used to determine a rating.