WTKO20 RKSL 161800 KMA TROPICAL CYCLONE ADVISORY NO. 13 NAME 1607 CHANTHU ANALYSIS POSITION 161800UTC 35.6N 141.1E MOVEMENT N 12KT PRES/VMAX 990HPA 47KT FORECAST 12HR POSITION 170600UTC 40.3N 142.0E WITHIN 30NM PRES/VMAX 992HPA 45KT 24HR POSITION 171800UTC 47.9N 144.7E WITHIN 0NM PRES 994HPA KOREA METEOROLOGICAL ADMINISTRATION.