Pathetic fallacy is used in the opening scene of Macbeth: the thunder and lightening are part of the metonymy of "doom and gloom" which suggests elements of mystery, danger and the supernatural, which all happens before we are even introduced to any characters. When the witches enter, they present the supernatural element to the play which would cause an air of mystery and pose a potential threat to the rest of the characters. Due to the short length of the scene, the audience are left with questions: who are the witches? what do they want with Macbeth? They represent the unknown, which is reflected in the lack of information we gain from them.
When the witches re-appear in Act 1 Scene 3, the dialogue instantly seems gruesome and evil, which gives an insight into the witches characteristics. When Macbeth and Banquo enter, the witches appear to know a lot about Macbeth, however he seems to have never seen or met them before. They also state a prophecy that Macbeth shall become King, however, the audience are then informed that Banquo's son is to become King: this leaves the audience questioning not only how it is possible that Macbeth will become King, but also how the witches know.
The dialogue throughout Scenes 2 and 3 exhibit not only how callous the witches are, but also indicates similarities between themselves and Macbeth. Macbeth is depicted as a war hero, however the audience may regard him as ruthless, just as they see the witches. These similar traits may suggest to the audience that Macbeth could be easily led astray by the witches and their prophecy.