Mr. Poulson's post is right on. Show up and do the 30. If you don't, you'll have a warrant out for you and I promise you that warrant will out last your ability to run, no question!
It's almost guaranteed that your 30 day stretch will not be 30 days. I had a client serve 8 days on a 30 day sentence. Show up, get it over with and move on. If you don't, you'll be prosecuted for any number of offenses and your 30 days will end up being more like a year or more.
They could issue a warrant, bust down your door at 2AM, and haul you off to jail. The prosecutor may try to find some way to withdraw the plea. They could charge you with a new offense, some sort of absconding. Hopefully, the police will not perceive a weapon in your hand, and if they do, may they taser you instead of shooting. If you do not survive the shooting, you will not have to serve the 30 days.
Report as ordered! Really!
We do not have a client/attorney relationship until you make an appointment, we discuss your case face to face, I accept a retainer, and we explictly agree to enter into representation.