Quote Originally Posted by Chronos View Post
Thor's Lightning is probably also a renaming of some other spell, but we don't know which one, and none of the likely prospects is on the standard cleric list, so we continue to list that one explicitly as something that Durkon has, and which presumably came from one of his domains.
It is almost certainly Call Lightning, since the comic of Durkon using it shows it striking from the sky instead of from his fingertips, as it would with Lightning Bolt.

Call Lightning is the third level domain spell of the Forgotten Realms Storm Domain.