Abstract: The effect of collective flavor evolution in the presence of collisions and advection in core-collapse supernovae has been sought after for a while now. I will present the first numerical solution for this problem in the two flavor approximation in spherical geometry. The result is a quasi-steady state configuration which shows some interesting features. Due to the effect of collective flavor evolution, the decoupling radii for each neutrino species are modified, and I will discuss the implications of this. I will also discuss the presence of fast and slow flavor evolution in the vicinity of the neutrino decoupling region.