1. Birds of Prey Abnormal Behavior: Casca reports seeing multiple creatures of prey, such as ravens, crows, and kites, flying in unusual directions. This behavior is considered unnatural and is interpreted by some characters to symbolize impending chaos and change.
2. Unnatural Lightning and Thunder: The storm brings with it erratic lightning strikes and thunderclaps. These occur at unseasonal times and are described in a manner that suggests they differ from normal weather phenomena.
3. Casca's Encounter: Casca encounters a lean and hungry-look man during the storm. This man gives Casca a detailed description of the unusual happenings caused by the storm, leaving him perplexed and unsettled.
4. Lions Escaping: Cimber reveals that the lions kept at the Capitol had left their cages and roamed freely without harming anyone. This is seen as an unnatural occurrence that further underscores the exceptional nature of the storm.
5. Flavius and Marullus's Arrest: Flavius and Marullus, tribunes attempting to maintain order in Rome, are arrested for preventing people from celebrating Caesar's victory. Their arrest signifies growing unrest among the populace and foreshadows the challenges to Caesar's power that will unfold later in the play.
These events create an atmosphere of uncertainty and unrest among the characters. They also serve to add an element of supernatural or divine intervention, suggesting that forces beyond human control are at work, setting the stage for the significant events that will follow.