WTJP21 RJTD 040600 WARNING 040600. WARNING VALID 050600. WARNING IS UPDATED EVERY 6 HOURS. STORM WARNING. SEVERE TROPICAL STORM 1703 NANMADOL (1703) 992 HPA AT 33.6N 134.2E SHIKOKU MOVING EASTNORTHEAST 33 KNOTS. POSITION GOOD. MAX WINDS 50 KNOTS NEAR CENTER. RADIUS OF OVER 30 KNOT WINDS 90 MILES SOUTHEAST SEMICIRCLE AND 60 MILES ELSEWHERE. FORECAST POSITION FOR 041800UTC AT 35.0N 141.7E WITH 40 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 992 HPA, MAX WINDS 50 KNOTS NEAR CENTER. FORECAST POSITION FOR 050600UTC AT 36.6N 149.6E WITH 80 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 992 HPA, MAX WINDS 45 KNOTS NEAR CENTER. EXTENDED OUTLOOK. FORECAST POSITION FOR 060600UTC AT 44.5N 171.2E WITH 150 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 1000 HPA, MAX WINDS 35 KNOTS. BECOMING EXTRATROPICAL LOW. JAPAN METEOROLOGICAL AGENCY.=