The Catatumbo Lightning is an atmospheric phenomenon in Venezuela. It occurs strictly in an area located over the mouth of the Catatumbo River where it empties into Lake Maracaibo

1. Catatumbo has had nearly continous lightning, except during a period of drought.
2. There has already been speculation that uranium in the surrounding bedrock plays a role.
3. Water reacts with uranium to produce hydrogen gas.
4. Radiation from uranium can make a gas highly conductive.
5. Lightning is current running between earth and sun.
6. Electric current is going to take the path of least resistance.
I don't think it should be too hard to see what's going on.