WTKO20 RKSL 121200 KMA TROPICAL CYCLONE ADVISORY NO. 6 NAME 1702 MERBOK ANALYSIS POSITION 121200UTC 21.8N 114.4E MOVEMENT NNW 9KT PRES/VMAX 994HPA 41KT FORECAST 24HR POSITION 131200UTC 25.5N 115.6E WITHIN 0NM PRES 1004HPA KOREA METEOROLOGICAL ADMINISTRATION.