They decided to make the final, 'boss' tornado an F5?
So, they're all at aunt Meg's house enjoying their meal, and they're explaining to Melissa about the F2 tornado and the F3 tornado and the F4 tornado. And then Melissa asks them if there's an F5.
And everyone suddenly gets very quiet like she'd just said something incredibly profane to a six-year-old.
Well, actually, that'd be alright with me. What they really did was suddenly get real quiet as though no one could have possibly anticipated that she might ask the next logical question after having an F3 and F4 tornado described to her.
But anyway, that's not even what I'm wondering about; it's just a bizarre little scene that leads up to it. What I'm wondering about is, since the vibe they were obviously going for at the climax of the movie was the tornado-to-end-all-tornadoes, why did they settle for handing us an F5?
Now, granted, this was made back in 1996, and there were no F6 tornadoes ever having occurred on record at that point. In fact, there still aren't, even today as 2014 is fast approaching. The point is, a tornado with the highest windspeed on record happened just a couple years ago, in 2011, I think, a really strong F5 that came THIS short (only 2MPH if I recall) of being an F6, and even back in 1996, the possibility of one wasn't even considered unlikely, much less totally implausible or impossible.
It just seems to me that, if they had wanted to give the audience the impression of a truly devastating tornado, they should have written it so that the final encounter was with a tornado described as being the first in history to push the speed record into a new category. An F6 would not only have been entirely reasonable to conclude the film with (even back in '96, the strongest F5s weren't more than a dozen or so MPH out of range), but it would have represented a novel phenomenon for the characters to explore (granted, it'd've been new territory only quantitatively, not qualitatively of course, but it'd've atleast still been something).
(They could also have made the tornado look as big as they said it was; seriously, the size of the funnel wasn't anywhere even remotely close to the "mile-wide" diameter the dialogue describes it as.)