Dual-Doppler radar analysis of the enhancement of a precipitation system on the northern side of Mt. Halla, Jeju Island, Korea on 6 July 2007

► Considerable moist air in low altitudes and the terrain-modified horizontal rerouting of the wind. ► Detailed evolution of a precipitation system near the elliptical mountain with a steep slope by dual-Doppler radar data analyses. ► Long-lasting convection near the island compared to that over the sea off the island.