WTMA20 FIMP 231845 TTT WARNING OF GALE AT 1800 UTC, MODERATE TROPICAL STORM CHENGE 1001 HPA PHENOMENON: MODERATE TROPICAL STORM 4 (CHENGE) 1001 HPA POSITION: WITHIN 20 NM RADIUS OF POINT 10.1S / 57.8E (TEN DECIMAL ONE DEGREES SOUTH AND FIFTY SEVEN DECIMAL EIGHT DEGREES EAST) MOVEMENT: WEST 10 KT THREAT AREAS: SQUALLY WEATHER WITHIN A 150 NM RADIUS AROUND THE CENTER. GALE FORCE WINDS 35 KT AND VERY ROUGH TO HIGH SEAS WITHIN A 50 NM RADIUS FROM THE CENTRE, EXTENDING UP TO 60 NM IN THE NORTH-WESTERN QUADRANT, UP TO 65 NM IN THE SOUTH-WESTERN QUADRANT AND UP TO 70 NM IN THE SOUTH-EASTERN QUADRANT. NEAR GALE FORCE WINDS 30 KT AND ROUGH TO VERY ROUGH SEAS WITHIN A 75 NM RADIUS FROM THE CENTRE, EXTENDING UP TO 90 NM IN THE NORTH-WESTERN QUADRANT, UP TO 150 NM IN THE SOUTH-WESTERN QUADRANT AND UP TO 185 NM IN THE SOUTH-EASTERN QUADRANT. STRONG GUSTS UNDER SQUALLS. END=