WTJP33 RJTD 042100 WARNING 042100. WARNING VALID 052100. STORM WARNING. TROPICAL STORM 1511 NANGKA (1511) 992 HPA AT 11.4N 164.8E MARSHALLS MOVING WEST 16 KNOTS. POSITION FAIR. MAX WINDS 40 KNOTS NEAR CENTER. RADIUS OF OVER 30 KNOT WINDS 150 MILES. FORECAST POSITION FOR 050900UTC AT 11.7N 162.5E WITH 50 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 985 HPA, MAX WINDS 50 KNOTS NEAR CENTER. FORECAST POSITION FOR 052100UTC AT 12.1N 160.1E WITH 75 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 980 HPA, MAX WINDS 55 KNOTS NEAR CENTER. JAPAN METEOROLOGICAL AGENCY.=