User:RandomInfinity17/F6

An F6 rating is a hypothetical classification of tornado on the Fujita scale. Only two tornadoes were given such rating, both of which were unofficial and downgraded. Ted Fujita has since deemed an F6 rating "inconceivable".

Description
The original Fujita scale was designed as a theoretical 13-level scale (F0–F12) with F1 corresponding to the twelfth level of the Beaufort scale and F12 corresponding to Mach 1.0. After the Fujita scale was finalized, this approach was dropped as categories above F5 weren't intended to be used. On the finalized Fujita scale, the upper range for F5 windspeed is 318 mph. This means that the lower end for F6 would be 319 mph, and by using the original Fujita scale, it would end at 379 mph.

An F6 tornado would be described as having inconceivable damage. Small to medium sized objects such as cars or refrigerators would become missiles and cause serious damage. Automobiles would be launched over 100 m. Effects of an F5 tornado would likely be observed as well. Homes would be lifted from their foundation and disintegrate. Steel reinforced concreted structed would be extremely damaged. Trees would be debarked and snapped in half. It is theorized that the damage from such a tornado would be so great that the only evidence of and F6 rating would be ground scouring. It is also said that engineering studies wouldn't be able to identify any F6 damage.

Examples
The 1974 Xenia tornado, the most destructive tornado of the 1974 Super Outbreak, was originally rated as an F6 tornado by Fujita before later being downgraded to F5. The 1970 Lubbock tornado was also given an initial rating of F6 given by Thomas Grazulis before being downgraded to an F5. After surveying the damage path of the 1977 Smithfield tornado, Fujita considered rating the tornado F6. In Grazulis's book, F5-F6 Tornadoes, he said that if there was an F6 tornado caught on camera, it would be the 1995 Pampa, Texas, tornado that was officially rated F4. The 1999 Bridge Creek–Moore tornado had Doppler on Wheels (DOW) winds of 301 ± 20 mph (484 ± 32 km/h), which would place the higher-end wind speeds in the F6 range. However, the National Weather Service has stated that the tornado was rated F5 and won't be upgraded to F6.