I never understood how we did not invent some Explosive that could be shot into a cloud that could change the DNA of a tornado as it seems so simple .
Interesting thought experiment, but two major issues I can think of; energy and logistics.
The amount of energy in a supercell is massive, as are they (often tens of miles across and stretching as higher than 50,000ft), so you're probably going to need a comparably large detonation to make any kind of difference. Maybe something on the order of a "MOAB" for a blast effect, or a thermobaric weapon for the disruption to the air flows that would result, although I take it we all agree that literally going nuclear is out of the question, even though it might even be able to get the job done?
Supercells are also chock full of water vapour, so any ignition of powder or aerosol based thermobaric weapons might be problematic as well, not to mention any ground effects of the shockwave of a large airburst weapon of either type. Where you detonate is going to matter a lot as well; is that near the top of the anvil, in the heart of the cell, or at the base where the funnels form? The lower you go, the more chance of the shockwave causing more destruction than the twister might have done - especially if you're not entirely sure who or what might be in range.
The real killer for me though is logistics. Firstly of the supercell; just because you have a supercell doesn't mean it's going to form a twister, let alone at a time you can predict, so when you you fire and, per the above, at what part of the supercell? These devices are probably not going to be cheap so you don't want to be wasting shots on a whim, yet storms can go from funnel to devastation in minutes so you can't hang around either.
Then there's the logistics of the geographical area; you're basically looking at something like a larger scale version of Israel's Iron Dome missile defence system covering, as a minimum, all the major population areas of the Mid-West. IIRC, one MOAB requires a modified C130 to "drop", so hardly practical for an Iron Dome type system. Thermobaric might work, as they are apparently capable of being mounted to a cruise missile, and might even be relatively cheap since they are basically flour bombs, but you'd still need to initiate combustion in a very wet and active environment. And then there's all those international laws banning their use that you'd need to square away...
Yes, tornadoes can - and do - cause a lot of damage and also claim a modest number of lives each year (circa 100 in the US), but in the scheme of things they're barely a blip on the radar. If you want to save lives and protect property, you'd probably do much better putting those funds into things like healthcare, transportation safety, infrastructure maintenance, and so on.
, I think there are much better things that the money could be spent on to protect lives and/or property.
