WTKO20 RKSL 121200 KMA TROPICAL CYCLONE ADVISORY NO. 18 NAME 1814 YAGI ANALYSIS POSITION 121200UTC 27.8N 122.4E MOVEMENT NW 19KT PRES/VMAX 992HPA 39KT FORECAST 24HR POSITION 131200UTC 32.9N 117.8E WITHIN 60NM PRES/VMAX 996HPA 33KT 36HR POSITION 140000UTC 35.0N 116.7E WITHIN 0NM PRES/VMAX 1000HPA 25KT KOREA METEOROLOGICAL ADMINISTRATION.