[en] We present analytical and kinetic Monte Carlo simulation (KMC) study for the (2+1) dimensional discrete growth model. A non-local, phenomenological continuum equation describing surface growth in unstable systems with anomalous scaling is proposed. The roughness of the unstable surface, originated from an Ehrlich-Schwoebel (ES) barrier, is then studied under various deposition fluxes. The induced meandering instability is found, unexpectedly, to be described by a linear growth continuum equation but with spatiotemporally correlated noise