Characteristics of environmental factors associated with typhoon Kongrey (1825) over the Eastern Coastal Region of Korea

In this study, the characteristics of environmental factors associated with typhoon Kongrey were examined using radiosonde, wind-profiler, radar, and Automated Surface Observing System (ASOS) data in Uljin, which is located the eastern coast of Korea. The radiosonde data were obtained from intensive observation between 1500 LST 5 to 0000 LST 7 October 2018. Environmental factors such as Total Precipitable Water (TPW) and Strom Relative Environmental Helicity (SREH) were selected to examine their relations to typhoon-accompanied precipitation. The TPW peak with 60.54 mm appeared at 1200 LST 6 October, which is 6 h after the peak of typhoon precipitation. It was found that the TPW variation is largely associated with the effect of water vapor supply from the typhoon with nearest proximity to Uljin at 1500 LST 6 October. Mean SREH, which indicates mechanical instability, was 761 m² s⁻² during the period in which typhoon precipitation occurred. These environments would provide a good condition for the development of super-cell storms, causing heavy precipitation associated with typhoon. In addition, it was found that the correlation coefficient between SREH and typhoon rainfall is 0.8 (p-value = 0.02).