WTKO20 RKSL 161200 KMA TROPICAL CYCLONE ADVISORY NO. 12 NAME 1607 CHANTHU ANALYSIS POSITION 161200UTC 34.4N 141.0E MOVEMENT NNW 13KT PRES/VMAX 990HPA 47KT FORECAST 12HR POSITION 170000UTC 37.8N 141.2E WITHIN 30NM PRES/VMAX 992HPA 45KT 24HR POSITION 171200UTC 44.0N 142.9E WITHIN 75NM PRES/VMAX 994HPA 41KT 36HR POSITION 180000UTC 50.3N 144.8E WITHIN 0NM PRES 998HPA KOREA METEOROLOGICAL ADMINISTRATION.