WTXS31 PGTW 242100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 07S (CHALANE) WARNING NR 001// RMKS/ 1. TROPICAL CYCLONE 07S (CHALANE) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 241800Z --- NEAR 15.8S 57.4E MOVEMENT PAST SIX HOURS - 240 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT REPEAT POSIT: 15.8S 57.4E --- FORECASTS: 12 HRS, VALID AT: 250600Z --- 15.7S 55.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 280 DEG/ 07 KTS --- 24 HRS, VALID AT: 251800Z --- 15.5S 54.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 270 DEG/ 06 KTS --- 36 HRS, VALID AT: 260600Z --- 15.5S 52.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 260 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 261800Z --- 15.8S 51.3E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 250 DEG/ 10 KTS --- 72 HRS, VALID AT: 271800Z --- 17.1S 47.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 240 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 281800Z --- 18.6S 44.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 270 DEG/ 08 KTS --- 120 HRS, VALID AT: 291800Z --- 18.5S 41.1E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT --- REMARKS: 242100Z POSITION NEAR 15.8S 56.9E. 24DEC20. TROPICAL CYCLONE (TC) 07S (CHALANE), LOCATED APPROXIMATELY 258 NM NORTH OF PORT LOUIS, MAURITIUS, HAS TRACKED WEST- SOUTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED, WITH HIGH CONFIDENCE, ON ENHANCED INFRARED SATELLITE IMAGERY (EIR) AND A 241621Z METOP-A ASCAT PASS. THE INITIAL INTENSITY IS BASED ON THE AFOREMENTIONED ASCAT PASS SHOWING A SWATH OF 30-35KT WINDS IN THE SOUTHERN SEMICIRCLE. THE POSITION IS FURTHER SUPPORTED BY A 241735Z METOP-B 89GHZ MICROWAVE IMAGE. THE INTENSITY IS OVERALL FAVORABLE WITH WARM SEA SURFACE TEMPERATURES (28-29 DEGREES CELSIUS), FAIR POLEWARD OUTFLOW AND LOW VERTICAL WIND SHEAR (10-15 KNOTS). TC 07S IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A NEAR EQUATORIAL STEERING RIDGE TO THE NORTH. TC 07S IS EXPECTED TO CONTINUE TRACKING GENERALLY WESTWARD THROUGH THE FIRST 72 HOURS AS IT MAKES LANDFALL ON MADAGASCAR. DUE TO THE MOUNTAINOUS TERRAIN OF MADAGASCAR, TC 07S IS EXPECTED TO WEAKEN FROM FRICTIONAL EFFECTS. AFTER TAU 72, TC 07S WILL TURN SOUTHWESTWARD AND RE-INTENSIFY IN THE MOZAMBIQUE CHANNEL. NUMERICAL MODEL TRACK GUIDANCE IS IN OVERALL GOOD AGREEMENT, WITH A CROSS-TRACK SPREAD OF 165NM AT TAU 72, FURTHER INCREASING TO 320NM BY TAU 120. THE CURRENT FORECAST IS CONSISTENT WITH THE MULTI-MODEL CONSENSUS. INTENSITY GUIDANCE IS MORE CONVOLUTED, WITH A HIGH SPREAD IN MEMBERS BEFORE AND AFTER MAKING LANDFALL IN MADAGASCAR. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241800Z IS 11 FEET. NEXT WARNINGS AT 250900Z AND 252100Z.// NNNN