The bottom of the rain clouds was maybe 0.5 km above ground level. That's a lower bound on how far all that rain had to fall. Using \(g \approx \)10 m/s2, that's about 4 x 1015 J of energy, deposited in about 20000 sec, for an average power delivered of 2 x 1011 Watts, as much as 100 municipal-scale power stations. That doesn't even account for the energy contained in the wind and the lightning discharges.
Remember, this is all being driven by the sun, through temperature differences that are at most 20 K. Thermodynamics tells us that the most efficient this process could possibly be is something like 1 - (300 K/320 K) = 1/16. That means that the total energy involved had to be at least 6.4 x 1016 J = about 18 billion kW-h, and that's only one part of a big storm system. This is why engineering the weather is a non-starter!