What is juliets premonition when romeo climbing down the ladder?

When Juliet sees Romeo climbing down the ladder after their wedding night, she has a premonition that something terrible is about to happen. She says, "Methinks I see some consequence yet hanging in the stars which will bitterly begin his fearful date with this night's revels." Juliet's premonition is realized when Romeo is banished from Verona for killing Tybalt.