Can you please explain to me how these events witnessed by Casca in...

Can you please explain to me how these events witnessed by Casca in Julius Caesar (Shakespeare) describes or foreshadow what is to come and how they suggest that there will be Chaos in Rome. I am having trouble understanding. Thanks!

Act 1 Scene 3

Casca:

A common slave--you'd know him well by sight-- 

Held up his left hand, which did flame and burn 

Like twenty torches join'd, and yet his hand 

Not sensible of fire remain'd unscorch'd. 

Besides,--I ha' not since put up my sword,-- 

Against the Capitol I met a lion, 

Who glared upon me, and went surly by, 

Without annoying me: and there were drawn 

Upon a heap a hundred ghastly women, 

Transformed with their fear; who swore they saw 

Men, all in fire, walk up and down the streets. 

And yesterday the bird of night did sit 

Even at noonday upon the marketplace, 

Howling and shrieking.

When these prodigies 

Do so conjointly meet, let not men say 

"These are their reasons; they are natural"; 

For I believe they are portentous things 

Unto the climate that they point upon.