WTJP31 RJTD 041500 WARNING 041500. WARNING VALID 051500. STORM WARNING. SEVERE TROPICAL STORM 1504 MAYSAK (1504) 985 HPA AT 14.8N 124.1E SEA EAST OF PHILIPPINES MOVING WEST 10 KNOTS. POSITION FAIR. MAX WINDS 50 KNOTS NEAR CENTER. RADIUS OF OVER 30 KNOT WINDS 150 MILES NORTH SEMICIRCLE AND 120 MILES ELSEWHERE. FORECAST POSITION FOR 050300UTC AT 16.9N 122.1E WITH 50 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 990 HPA, MAX WINDS 45 KNOTS NEAR CENTER. FORECAST POSITION FOR 051500UTC AT 18.8N 119.7E WITH 75 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 994 HPA, MAX WINDS 40 KNOTS NEAR CENTER. JAPAN METEOROLOGICAL AGENCY.=