The effect of temperature of polymeric melt on the size of the vortex area arising in case of a flow on an entrance to the slot-hole channel is considered. Mathematical modeling of a three-dimensional melt flow in the converging plane-parallel channel is performed using the modified Vinogradov-Pokrovsky rheological model generalized to account the non-monotonic gradient dependence of elongation viscosity in presence of the residual viscosity with Newtonian behavior. The sticking boundary conditions for the velocity are posed on the wall. The Arrenius temperature dependence of initial shear viscosity of polymeric melt was used. The initial relaxation time was estimated by comparison with the experimental data for gradient dependence of stationary viscosity of uniaxial elongation as well as on the basis of molecular-kinetic theory. The discrete analogs of dynamic equation systems of polymeric liquids were constructed by the control volume approach with separation on physical processes. The possibility of application of parallel computing technology based on graphical processors was considered in case of implementation of numerical algorithm. The reverse polymeric melt flows on the entrance to the channel narrow part are found on the basis of the numerical simulations. It is shown that the dependence of the vortex size on the melt temperature is non-monotonic and has a maximum. It is also shown that the polymeric fusion flow on the entrance to the slot-hole channel is significantly three-dimensional; the sizes of the vortex area calculated in the sections which are carried out at various distances from an axis of the channel initially increase at the approach to the rigid wall, and then decrease. All the features found on the basis of the simulations are observed also in real experiments on low density melts of branched polyethylene.