WTJP21 RJTD 291200 WARNING 291200. WARNING VALID 301200. WARNING IS UPDATED EVERY 6 HOURS. TYPHOON WARNING. TYPHOON 1821 JEBI (1821) 975 HPA AT 17.3N 151.4E SEA AROUND OF MINAMITORISIMA MOVING WEST 10 KNOTS. POSITION FAIR. MAX WINDS 70 KNOTS NEAR CENTER. RADIUS OF OVER 50 KNOT WINDS 50 MILES. RADIUS OF OVER 30 KNOT WINDS 180 MILES EAST SEMICIRCLE AND 120 MILES ELSEWHERE. FORECAST POSITION FOR 300000UTC AT 17.5N 149.3E WITH 30 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 960 HPA, MAX WINDS 80 KNOTS NEAR CENTER. FORECAST POSITION FOR 301200UTC AT 17.8N 147.1E WITH 60 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 950 HPA, MAX WINDS 90 KNOTS NEAR CENTER. EXTENDED OUTLOOK. FORECAST POSITION FOR 311200UTC AT 19.1N 142.0E WITH 110 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 935 HPA, MAX WINDS 100 KNOTS NEAR CENTER. FORECAST POSITION FOR 011200UTC AT 21.9N 138.1E WITH 140 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 935 HPA, MAX WINDS 100 KNOTS NEAR CENTER. JAPAN METEOROLOGICAL AGENCY.=