The warrant is out for your arrest. If you don't show up and turn yourself in you can go to jail for even longer than you were originally supposed to go for. It's possible you could even get a fine of some sort. It also won't look good on your record.
Very simply, if you get caught you will be arrested and charged for failure to appear in court. Very likely it could mean additional jail time, even if the original charge was minor enough to avoid going to jail.