ceraunomancy

cerauno- +‎ -mancy; based on earlier ceraunoscopy.

ceraunomancy (uncountable)

1. (uncommon) Divination by thunder; the use of thunder or lightning to supernaturally gain information.
   • 2007, Evan Samuel Heimlich, Divination by the Ten Commandments: Its Rhetorics and their Genealogies, page 187:

     Indeed as DeMille in 1956 filmed the Decalogue, God inscribes each commandment literally with a bolt of lightning. Because the film functions to read the signs of the times, the practice here invokes ceraunomancy (divination by lightning).

   • 2016, Kyle Grothoff, Astrology in Augustan Rome: A Cultural History, page 68:

     Whether or not that is true, the equal weight given to public and private contexts in the sources for Etruscan ceraunomancy certainly does provide a corrective to our literary sources and their preoccupation with public divination whence one might be led to believe that traditional divination was exclusively public or communal in nature prior to the first-century..

2. (uncommon) The magical or supernatural power of conjuring or controlling thunder or lightning.

• brontomancy
• ceraunoscopy