I, for one, would be happy to know your reasoning!
I’ll list my big three reasons here, in order from most impressive to least:
1. Extreme ground scouring
that coincides with deep trenching and other extreme contextuals/damage. This is by far the biggest case for why this tornado got the rating and the surveyors gave it the EF5 rating based on this, and it’s valid. While people (quite understandably) make the assumption that any tornado that does “trenching” is automatically violent, it is actually not the case - some far weaker tornadoes have been known to do this sort of damage to the ground.
However, the trenching done by Philadelphia was clearly and evidently very unique and indicated EF5 intensity. For one, the trenching done by the storm is consistent in long streaks, and is preceded by impressive grass scouring comparable to other violent tornadoes.
The biggest reason why this indicates EF5 intensity, however, is because of how the trenching was done. If we compare it to other dug trenches from other weaker tornadoes (Mayfield comes to mind) the trenching done by that tornado is more like a “sheet” was peeled from the ground, which to me (and others who are more qualified than me) indicates that the top layer of soil was particularly prone to high winds there. In Philadelphia’s case, it was a compact grazing pasture that was studied after the fact and found to be very similar to Plains soils used for cattle farms and whatnot (I don’t remember the exact source of this but I’ve heard it repeated on multiple outlets). The grass in these trenches was forcefully ripped and stripped out of the bedrock in large clumps of dirt. It obviously takes
immense force to do this, and it helps that Smithville did something similar and arguably less intense before inflicting, as you know, some of the most intense EF5 damage ever documented. It also lasted for nearly 200 yards, which I believe would be enough for it to not just be considered a weaker layer of soil. There’s much more that could be said about this particular point, but I’m not going to get into it here as it is beyond my level of understanding.
This, to me, is the bottom line in why this tornado deserved EF5, and the surveyors seemed to think this to the point where they went outside the confines of the scale.
2. Contextuals coinciding with this damage. A very large tree in the path of the extreme scouring was entirely debarked and ripped out by the root ball, then tossed ~40 yards outside of the scouring. Pavement scouring was also noted later in the path, where the trenching was existent but less intense. The second area of EF5 damage was arguably not EF5 intensity despite being given the rating and I can understand that, but even if it’s not, it still adds credence to the idea that the first area of EF5 damage was in fact EF5 damage. Also, the third point does support maxed-out damage in the second area.
3. The occupied double wide mobile home. If you are not aware of what happened here, a double wide mobile home with three people inside (RIP to these victims) was picked up, and in a single toss, thrown 300 yards without having touched the ground a single time. It disintegrated and was granulated upon impact with the ground. This, again, was co-located with the second area of EF5 rated damage. There’s probably more that could be said about these points individually, as well as more reasons I didn’t say here, but I believe these three reasons are more than enough evidence to support not just baseline, but high end EF5 intensity. I do not see a baseline EF5 doing some of this damage. That’s my two cents.
