  We study the quantum Goos-H\"{a}nchen (GH) shift and the tunneling
transmission at a curved step potential by investigating the time evolution of
a wave packet. An initial wave packet is expanded in terms of the eigenmodes of
a circular step potential. Its time evolution is then given by the interference
of their simple eigenmode oscillations. We show that the GH shift along the
step boundary can be explained by the energy-dependent phase loss upon
reflection, which is defined by modifying the one-dimensional (1D) effective
potential derived from the 2D circular system. We also demonstrate that the
tunneling transmission of the wave packet is characterized by a free-space
image distant from the boundary. The tunneling transmission exhibits a rather
wide angle divergence and the direction of maximum tunneling is slightly
rotated from the tangent at the incident point, which is consistent with the
time delay of the tunneling wave packet computed in the 1D modified effective
potential.
