[thaumasiotes]

We routinely dump lightning bolts right into the ground and they go well beyond multiple megawatts. They're very brief, but if lightning took ten seconds to strike, it would still provide several dozen megawatts of power. How quickly would we be melting the ground at the multi-MW scale? How many lightning bolts would it take before the ground around my house melted and flowed downhill?

[Scarblac]

Lightning bolts do in fact melt the ground (see fulgurite), and they take at most about 0.2 seconds.

[eecc]

Yes very localized and for a very short amount of time and most of the energy radiated away into the surroundings, including the atmosphere