1. National Center for Agro-Meteorology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744, Republic of Korea
2. Forecast Research Laboratory, National Institute of Meteorological Research, 45 Gisangcheong-gil, Dongjak-gu, Seoul 156-720, Republic of Korea
3. Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20742, USA