WTJP21 RJTD 161200 WARNING 161200. WARNING VALID 171200. WARNING IS UPDATED EVERY 6 HOURS. STORM WARNING. SEVERE TROPICAL STORM 1501 MEKKHALA (1501) UPGRADED FROM TROPICAL STORM 985 HPA AT 11.3N 128.1E SEA EAST OF PHILIPPINES MOVING WEST 12 KNOTS. POSITION FAIR. MAX WINDS 50 KNOTS NEAR CENTER. RADIUS OF OVER 30 KNOT WINDS 210 MILES NORTH SEMICIRCLE AND 150 MILES ELSEWHERE. FORECAST POSITION FOR 170000UTC AT 11.7N 126.7E WITH 50 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 980 HPA, MAX WINDS 55 KNOTS NEAR CENTER. FORECAST POSITION FOR 171200UTC AT 12.3N 125.4E WITH 70 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 975 HPA, MAX WINDS 60 KNOTS NEAR CENTER. EXTENDED OUTLOOK. FORECAST POSITION FOR 181200UTC AT 13.8N 122.4E WITH 110 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 985 HPA, MAX WINDS 50 KNOTS NEAR CENTER. FORECAST POSITION FOR 191200UTC AT 15.7N 120.7E WITH 160 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 1002 HPA. BECOMING TROPICAL DEPRESSION. JAPAN METEOROLOGICAL AGENCY.=