First, I know you already know the answer to the question since you posted 8 months ago and the hearing was the day after the post, but for others who are curious, the answer is, maybe. Normally, the courts do not place people under arrest at an advisement hearing. The advisement hearing is just to advise the party of the contempt violation. At that hearing, the party pleads either guilty or not guilty. Then the court sets the matter for a hearing on the contempt violations.
The reason I say, "maybe" is because the court could place that individuals under arrest if the attorney for child support enforcement (CSE) argues they are a flight risk and will likely fail to appear at the hearing date. Even when CSE makes that motion, it is up to the court to determine whether to place that person in custody immediately. In my experience, I have never seen that happen. But like I tell clients - anything can happen.
The penalties for violation of a generic contempt citation are up to 6 months in jail and/or repayment of attorney fees and costs. There are 2 types of contempt - punitive, which includes jail time or remedial, which is repayment of the ordered amount (in your case $15k in child support) and repayment of attorney fees and cost. A party may also seek both types of contempt in their motion.
Usually, courts do not impose jail time on a first offense (or at least not much depending on the severity of the offense). Multiple offenses carry heavier jail sentences. Of course, all of these factors are contingent on each individual experience.
You can also request (as the victim) a lighter sentence based on whatever circumstances you advise the court. You are also free to negotiate a lesser amount owed by your ex. This would result in a stipulation between you and your ex which lowers the amount of arrears he owes. I do that all the time, lowering amount of child support and arrears owed. So it can be done. You do not need an attorney and can make CSE aware of your agreement on amount of child support and arrears owed. That gets into a whole other topic about voluntary stipulations to reduction of child support and arrears. But it can be done by the agreement of the parties.