The National Weather Service has downgraded the EF-5 El Reno Tornado of May 31 to EF-3. The ostensible reason is because (along a very sparsely populated path) the worst damage was EF-3 (138 to 167 mph). It was upgraded to EF-5 because of a close-up mobile radar reading of 290 mph winds. The NWS wants to "honor the intent" of the EF scale (according to one NWS meteorologist), thus the downgrade. I believe this is a poor, and dangerous, decision.
Some background, the 'Enhanced' Fujita Scale replaced the original Fujita tornado intensity scale for NWS purposes in 2007. It differs from the original by lowering the wind speeds for strong tornadoes. F-5 was 261 to 319 mph. EF-5 is 200 mph or greater.
We have two extreme wind readings from mobile radars in the State of Oklahoma: 318 mph in 1999 and 290 mph in the El Reno storm. Those readings are much more compatible with Ted's original than the EF. Plus, Ted's original explicitly allowed instrumental measurements (see image below) where I
have circled the wind speed, as opposed to damage, scale.
Unfortunately, this is not academic. If a nuclear power plant, for example, is built in the tornado belt, it needs to be about to withstand 300+mph gusts (worst case scenario). By intentionally putting the El Reno tornado into the database weaker than it really was, it could mislead non-meteorologists (i.e., architects and building engineers) into under-designing buildings. For example, this FEMA design document references only the EF-scale.
Given its better grasp of tornado's upper-end wind speeds and that using the best data is an impediment to the EF-Scale, I believe we need to go back to the original F-Scale.