Split up a given sentence into two sentences.
It was a hot day with a thunderstorm on the horizon.
It was a hot day. There was a thunderstorm on the horizon.
Complete the following task based on the instruction and optional input provided.### Instruction:
Split up a given sentence into two sentences.

### Input:
It was a hot day with a thunderstorm on the horizon.

### Output:
It was a hot day. There was a thunderstorm on the horizon.