During the Cataclysm expansion Al'Akir and his Air Elemental servants ally themselves with Deathwing. Players are sent to Skywall, Al'Akir's domain to dispose of him. Upon reaching 80% health during his boss fight Al'Akir get's serious and proceeds to create a grand thunderstorm.
This is the third and final calc of a series of storm calcs for the Warcraft franchise, they'll also be my first calcs ever so any advice is appreciated.
Al'Akir's domain is floating somewhere in or slightly above the clouds:
For that reason I'm making the assumption that we're at least at the level of low level clouds or 2000 meters. Jumping into the Horizon calculator I find out that the view distance from such a vantage point would be 159700 meters.
Next up is the speed of the storm's creation. At 0:03 the clouds still haven't began to darken at all and by 0:09 rain is already beating down hard on the platform and the storm clouds have formed and darkened completely. That gives me a window of around 5 seconds for the storm's creation.
I'm assuming that the storm cloud's height is at least 13,000 meters and that cloud density is 1.003 kg per cubic meter.
I'm using Spinosaurus75DinosaurFan's calculation, all credits for it goes to him.
(159700/5)^2*(3.14*159700^2*13000*1.003)*0.5 = 5.3289767e+23
5.3289767e+23 Joules joules or 127 teratons of TNT Large Country level
If accepted this will scale to at least the other Elemental Lords and the Keepers Odyn and Ra-Den as well as other possible Keeper profiles. This is somewhat supported by a legend about one of the keepers Thorim who supposedly destroyed a continent. Thorim was one of the three keepers who fought and subdued Al'Akir in ancient times.