WTMA20 FIMP 221830 TTT WARNING OF STORM FORCE AT 1800 UTC, SEVERE TROPICAL STORM 11 (HORACIO) 990 HPA WAS CENTRED WITHIN 30 NM RADIUS OF POINT 17.9 S / 68.1 E (SEVENTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY EIGHT DECIMAL ONE DEGREES EAST). MOVEMENT: WEST-SOUTH-WEST 10 KT THREAT AREAS: SQUALLY WEATHER WITHIN A 160 NM RADIUS AROUND THE CENTER. STORM FORCE WINDS 50 KT AND HIGH TO VERY HIGH SEAS EXTENDING UP TO 40 NM IN THE SOUTHERN SEMI-CIRCLE AND THE NORTH-WESTERN QUADRANT. GALE FORCE WINDS 35/45 KT AND VERY ROUGH TO HIGH SEAS WITHIN A 65 NM RADIUS FROM THE CENTRE, EXTENDING UP TO 75 NM IN THE WESTERN SEMI-CIRCLE AND UP TO 90 NM IN THE SOUTH-EASTERN QUADRANT. NEAR GALE FORCE WINDS 30 KT AND ROUGH TO VERY ROUGH SEAS WITHIN A 85 NM RADIUS FROM THE CENTRE, EXTENDING UP TO 95 NM IN THE NORTH-WESTERN QUADRANT, UP TO 110 NM IN THE SOUTH-WESTERN QUADRANT AND UP TO 160 NM IN THE SOUTH-EASTERN QUADRANT. STRONG GUSTS UNDER SQUALLS. END=