London's surface area is 1,572km^2, which translates to about 1.572e+9m^2. These aren't true storm clouds; according to the OBD, the average cloud has a thickness of 2 kilometers, so the volume of this pseudo-storm would be roughly 3.144e+12m^3, which means their volume would be 3.153432e+12kg.
The radius of a circle with this area would be 22369.25 meters. We will have to use this to find the rotational speed of the clouds.
The problem is, we don't know the timeframe. I'll assume 10 seconds, since it all took place in a single panel and she is still speaking while it forms. We now have to plug this into the rotational speed formula. Assuming a fourth of a full rotation:
- (2*pi*22369.25)/4/10 = 35137.5357332m/s
Now that we have the speed, we plug that into the KE formula:
- 0.5*3.153432e+12*35137.5357332^2 = 1.9466868e+21 joule, or 465 gigatons (Large Island level)
- Did the storm cover all of London's extension, or just one side to the other?
- Were all the clouds rotating at the same speed? I'd have to halve the radius otherwise, which would lower the result, although it'd still be 6-C
I forgot to divide by 10 in the speed formula.
True result would be 1.9466868e+19 joules, or 4.652 gigatons (Island level)