WTXS31 PGTW 271500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 014// RMKS/ 1. TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 014 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 271200Z --- NEAR 19.4S 90.3E MOVEMENT PAST SIX HOURS - 275 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 19.4S 90.3E --- FORECASTS: 12 HRS, VALID AT: 280000Z --- 19.0S 87.3E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 275 DEG/ 16 KTS --- 24 HRS, VALID AT: 281200Z --- 18.6S 84.0E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 280 DEG/ 16 KTS --- 36 HRS, VALID AT: 290000Z --- 18.1S 80.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 280 DEG/ 16 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 291200Z --- 17.5S 77.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 280 DEG/ 16 KTS --- 72 HRS, VALID AT: 301200Z --- 16.4S 71.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 280 DEG/ 14 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 311200Z --- 15.4S 65.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 275 DEG/ 11 KTS --- 120 HRS, VALID AT: 011200Z --- 14.8S 60.6E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT --- REMARKS: 271500Z POSITION NEAR 19.3S 89.5E. 27JAN21. TROPICAL CYCLONE (TC) 13S (THIRTEEN), LOCATED APPROXIMATELY 1861 NM EAST OF PORT LOUIS, MAURITIUS, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES FLARING DEEP CONVECTION OVER A BROAD LOW-LEVEL CIRCULATION. A 271058Z SSMIS 91GHZ COMPOSITE MICROWAVE IMAGE REVEALS SHALLOW BANDING WRAPPING INTO A DEFINED CENTER WITH ISOLATED DEEP CONVECTION OVER THE SOUTHERN SEMICIRCLE. THE INITIAL INTENSITY OF 30 KNOTS IS HEDGED ABOVE THE PGTW CURRENT INTENSITY ESTIMATE OF 1.5 (25 KNOTS) BASED ON A 261100Z ADT ESTIMATE OF 2.0 (30 KNOTS). ENVIRONMENTAL ANALYSIS INDICATES A MARGINALLY-FAVORABLE ENVIRONMENT WITH GOOD POLEWARD OUTFLOW OFFSET BY MARGINAL SST VALUES (26-27C) AND DRY AIR ENTRAINMENT. TC 13S IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE ENTRENCHED TO THE SOUTH. NUMERICAL MODEL GUIDANCE REMAINS IN CLOSE AGREEMENT THROUGH THE FORECAST PERIOD LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. TC 13S IS EXPECTED TO STRUGGLE UNDER MARGINAL CONDITIONS THROUGH TAU 36, HOWEVER, THE SYSTEM SHOULD BE ABLE TO INTENSIFY GRADUALLY AFTER TAU 36 AS SST VALUES (28-29C) WARM. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 271200Z IS 13 FEET. NEXT WARNINGS AT 280300Z AND 281500Z.// NNNN