Symbolism, Imagery, Allegory
Another sign that Oedipus is expecting is related to natural calamities. He knows that his life will be over when he gets the following signs:
Either an earthquake or some thunder or lightning from Zeus. (95)
He announces this at the beginning of the play in what we'd call a pretty heavy-handed use of foreshadowing.
Sure enough, bring on the thunder machines. The storm comes rolling in and Oedipus recognizes it as his last farewell:
This winged thunder from Zeus will at once
Take me to Hades. (1460-61)
The natural occurrences of earthquakes and thunder are, for Oedipus, more than just another Weather Channel special feature. The natural world is the manifestation of the divine world of the gods and their plans. In this case, a storm means the sweet release of death.