Thunder's Predecessor
This page is the CodyCross answer for the clue below from Top Secret, Group 2099, Puzzle 1 (Signal Jammer).
Question is: Thunder's Predecessor
and the answer is: LIGHTNING
Word Meaning:
LIGHTNING — A flash of light produced by short-duration, high-voltage discharge of electricity within a cloud, between clouds, or between a cloud and the earth.
Definitions from Wiktionary.