WTJP31 RJTD 032100 WARNING 032100. WARNING VALID 042100. TYPHOON WARNING. TYPHOON 1821 JEBI (1821) 945 HPA AT 31.3N 133.3E SEA SOUTH OF JAPAN MOVING NORTHNORTHEAST 20 KNOTS. POSITION GOOD. MAX WINDS 85 KNOTS NEAR CENTER. RADIUS OF OVER 50 KNOT WINDS 100 MILES SOUTHEAST SEMICIRCLE AND 50 MILES ELSEWHERE. RADIUS OF OVER 30 KNOT WINDS 240 MILES SOUTHEAST SEMICIRCLE AND 120 MILES ELSEWHERE. FORECAST POSITION FOR 040900UTC AT 37.1N 136.6E WITH 40 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 965 HPA, MAX WINDS 70 KNOTS NEAR CENTER. FORECAST POSITION FOR 042100UTC AT 45.0N 139.1E WITH 80 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 975 HPA, MAX WINDS 55 KNOTS NEAR CENTER. JAPAN METEOROLOGICAL AGENCY.=