WTSS20 VHHH 191345 TROPICAL CYCLONE WARNING AT 191200 UTC, SEVERE TROPICAL STORM KOPPU (1524) WITH CENTRAL PRESSURE 980 HECTOPASCALS WAS CENTRED WITHIN 90 NAUTICAL MILES OF ONE EIGHT POINT ONE DEGREES NORTH (18.1 N) ONE TWO ZERO POINT TWO DEGREES EAST (120.2 E) AND IS FORECAST TO BE SLOW MOVING FOR THE NEXT 24 HOURS. MAXIMUM WINDS NEAR THE CENTRE ARE ESTIMATED TO BE 55 KNOTS. RADIUS OF OVER 33 KNOT WINDS 150 NAUTICAL MILES OVER NORTHERN SEMICIRCLE, 120 NAUTICAL MILES ELSEWHERE. RADIUS OF OVER 47 KNOT WINDS 45 NAUTICAL MILES. RADIUS OF OVER 2 METRE WAVES 300 NAUTICAL MILES. FORECAST POSITION AND INTENSITY AT 201200 UTC ONE EIGHT POINT FOUR DEGREES NORTH (18.4 N) ONE TWO ONE POINT FIVE DEGREES EAST (121.5 E) MAXIMUM WINDS 45 KNOTS. FORECAST POSITION AND INTENSITY AT 211200 UTC ONE NINE POINT TWO DEGREES NORTH (19.2 N) ONE TWO TWO POINT ZERO DEGREES EAST (122.0 E) MAXIMUM WINDS 50 KNOTS. FORECAST POSITION AND INTENSITY AT 221200 UTC TWO ZERO POINT SIX DEGREES NORTH (20.6 N) ONE TWO TWO POINT ZERO DEGREES EAST (122.0 E) MAXIMUM WINDS 55 KNOTS. FORECAST POSITION AND INTENSITY AT 231200 UTC TWO TWO POINT ONE DEGREES NORTH (22.1 N) ONE TWO TWO POINT ZERO DEGREES EAST (122.0 E) MAXIMUM WINDS 50 KNOTS. FORECAST POSITION AND INTENSITY AT 241200 UTC TWO THREE POINT SEVEN DEGREES NORTH (23.7 N) ONE TWO TWO POINT FIVE DEGREES EAST (122.5 E) MAXIMUM WINDS 50 KNOTS.