Abstract
On July 13, 2012, the bow echo was observed over the lee side of the Mt. Halla (1950 m above sea level) on Jeju Island, Korea. Three-dimensional wind-field and surface observation analyses were carried out to understand the structure and evolution of convective system with bow echo on the bell-shaped terrain. The northeastward-moving convective system passed over the approximately bell-shaped, isolated mountain with a mean speed of 17 m s-1. On the windward side of the mountain, the convective system developed by the inflow of unstable warm air from the ocean and terrain-induced upward motion, even with a low CAPE value of 511 J kg-1. When passing the lee side of the mountain, the bow echo was formed in the convective system by the strongest winds behind the bow echo. Behind the leading edge of the bow echo, the strengthened rear-inflow jet (RIJ) descended with relatively dry air along the surface, resulted in enhancing evaporative cooling. The precipitation-induced downdrafts generated a cold pool on the lee side of mountain. The development of an RIJ and cold pool formation both contributed to the evolution of the bow echo. In addition, the isolated bell-shaped terrain had a major indirect influence on the evolution of convective system with bow echo in this event.
