The thunder and lightening in the opening scene with the introduction of the three witches is symbolic of the havoc that they intend to wreck on human nature, particularly using Macbeth as their emissary of destruction.
Shakespeare uses nature, the disorder that is created by Macbeth's actions, killing a rightful, honorable king, Duncan, to illustrate how closely human feelings and actions are tied to the function that nature plays in the world. Lennox discusses the crazy night that just past, the night that Macbeth killed Duncan, with the Porter at his home.
"The night has been unruly. Where we lay,55)Our chimneys were blown down, and, as they say, Lamentings heard i’ the air, strange screams of death, And prophesying with accents terrible Of dire combustion and confused events
New hatch'd to the woeful time. The obscure bird(60) Clamor'd the livelong night. Some say the earth Was feverous and did shake." (Shakespeare)
The destructive forces that Macbeth unleashes when he disrupts the order of nature in Scotland is exemplified by the chaotic destruction that nature renders in response.
There are storms that destroy homes, raging violence is exhibited in the animal community, Duncan's horses are said to cannibalize each other in one scene.