Classify the given sentence as ironic, metaphorical, or literal.
"It is raining cats and dogs outside."
The given sentence, "It is raining cats and dogs outside," is an example of a metaphorical expression.
Complete the following task based on the instruction and optional input provided.### Instruction:
Classify the given sentence as ironic, metaphorical, or literal.

### Input:
"It is raining cats and dogs outside."

### Output:
The given sentence, "It is raining cats and dogs outside," is an example of a metaphorical expression.