WTJP32 RJTD 191500 WARNING 191500. WARNING VALID 201500. STORM WARNING. SEVERE TROPICAL STORM 1820 CIMARON (1820) UPGRADED FROM TROPICAL STORM 992 HPA AT 16.4N 149.8E MARIANAS MOVING WESTNORTHWEST 14 KNOTS. POSITION FAIR. MAX WINDS 50 KNOTS NEAR CENTER. RADIUS OF OVER 30 KNOT WINDS 270 MILES SOUTHEAST SEMICIRCLE AND 150 MILES ELSEWHERE. FORECAST POSITION FOR 200300UTC AT 17.4N 147.7E WITH 40 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 990 HPA, MAX WINDS 55 KNOTS NEAR CENTER. FORECAST POSITION FOR 201500UTC AT 18.5N 145.9E WITH 50 MILES RADIUS OF 70 PERCENT PROBABILITY CIRCLE. 985 HPA, MAX WINDS 60 KNOTS NEAR CENTER. JAPAN METEOROLOGICAL AGENCY.=