WTJP21 RJTD 031800 WARNING 031800. WARNING VALID 041800. WARNING IS UPDATED EVERY 6 HOURS. TYPHOON WARNING. TYPHOON 1504 MAYSAK (1504) 975 HPA AT 14.3N 127.8E SEA EAST OF PHILIPPINES MOVING WEST 11 KNOTS. POSITION GOOD. MAX WINDS 65 KNOTS NEAR CENTER. RADIUS OF OVER 50 KNOT WINDS 50 MILES. RADIUS OF OVER 30 KNOT WINDS 150 MILES NORTH SEMICIRCLE AND 120 MILES ELSEWHERE. FORECAST POSITION FOR 040600UTC AT 15.3N 124.9E WITH 50 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 980 HPA, MAX WINDS 55 KNOTS NEAR CENTER. FORECAST POSITION FOR 041800UTC AT 16.7N 122.8E WITH 75 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 985 HPA, MAX WINDS 50 KNOTS NEAR CENTER. EXTENDED OUTLOOK. FORECAST POSITION FOR 051800UTC AT 19.5N 119.0E WITH 140 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 996 HPA, MAX WINDS 40 KNOTS NEAR CENTER. FORECAST POSITION FOR 061800UTC AT 20.0N 117.5E WITH 160 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 1004 HPA. BECOMING TROPICAL DEPRESSION. JAPAN METEOROLOGICAL AGENCY.=