WTXS51 PGTW 270300 WARNING ATCG MIL 13S SIO 210127013825 2021012700 13S THIRTEEN 013 01 270 13 SATL 040 T000 195S 0918E 035 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T012 193S 0898E 035 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T024 189S 0871E 035 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T036 183S 0839E 035 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T048 177S 0800E 035 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T072 163S 0734E 040 R034 040 NE QD 050 SE QD 055 SW QD 065 NW QD T096 151S 0673E 045 R034 030 NE QD 060 SE QD 050 SW QD 040 NW QD T120 145S 0620E 050 R050 010 NE QD 020 SE QD 020 SW QD 000 NW QD R034 050 NE QD 040 SE QD 040 SW QD 060 NW QD AMP SUBJ: TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 013 1. TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 013 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 270000Z --- NEAR 19.5S 91.8E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 13 KTS POSITION ACCURATE TO WITHIN 040 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 - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT REPEAT POSIT: 19.5S 91.8E --- FORECASTS: 12 HRS, VALID AT: 271200Z --- 19.3S 89.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 280 DEG/ 13 KTS --- 24 HRS, VALID AT: 280000Z --- 18.9S 87.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 280 DEG/ 15 KTS --- 36 HRS, VALID AT: 281200Z --- 18.3S 83.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 280 DEG/ 19 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 290000Z --- 17.7S 80.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 280 DEG/ 16 KTS --- 72 HRS, VALID AT: 300000Z --- 16.3S 73.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 280 DEG/ 15 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 310000Z --- 15.1S 67.3E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 275 DEG/ 13 KTS --- 120 HRS, VALID AT: 010000Z --- 14.5S 62.0E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT --- REMARKS: 270300Z POSITION NEAR 19.4S 91.3E. 27JAN21. TROPICAL CYCLONE 13S (THIRTEEN), LOCATED APPROXIMATELY 1342 NM SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) REVEALS THAT THEY SYSTEM IS BEING INFLUENCED BY SUBSTANTIAL VERTICAL WIND SHEAR (VWS), WITH FLARING CONVECTION DISPLACED WELL TO THE SOUTHEAST OF THE EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). THE EXPOSED LLCC IN CONJUNCTION WITH A 262225Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS SHALLOW BANDING OVER THE WESTERN AND NORTHERN HEMISPHERE WRAPPING INTO A WELL DEFINED LLCC, PROVIDING HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY IS HEDGED ABOVE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T2.0 (30 KTS) BASED ON A 262340Z ADT ESTIMATE OF T2.7 (39 KTS) AND A SATCON ESTIMATE OF 36 KNOTS. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY SUPPORTIVE CONDITIONS CHARACTERIZED BY MODERATE (10-15 KTS) NORTHERLY VWS, GOOD POLEWARD OUTFLOW, MARGINAL SSTS (26C) AND ENTRAINMENT OF DRIER AIR, PARTICULARLY ON THE WEST AND NORTHERN PORTIONS OF THE CIRCULATION. TC 13S IS FORECAST TO TRACK WEST-NORTHWEST ALONG THE NORTHERN PERIPHERY OF A LOW TO MID-LEVEL STR ENTRENCHED TO THE SOUTH. THE SYSTEM WILL STRUGGLE AGAINST THE MARGINAL CONDITIONS THROUGH TAU 48, MAINTAINING AN AVERAGE INTENSITY OF 35 KNOTS WITH SLIGHTLY LOWER AND HIGHER EXCURSIONS ON A DIURNAL CYCLE. IF IT SURVIVES PASSAGE THROUGH THIS MARGINAL ENVIRONMENT, AND AS IT MOVES INTO AN IMPROVED ENVIRONMENT AFTER TAU 72, IT IS EXPECTED TO SLOWLY INTENSIFY TO A PEAK OF 50 KNOTS BY TAU 120. NUMERICAL MODEL GUIDANCE IS IN VERY GOOD AGREEMENT THROUGH THE DURATION OF THE FORECAST, LENDING HIGH CONFIDENCE TO THE TO THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270000Z IS 13 FEET. NEXT WARNINGS AT 271500Z AND 280300Z.// 1321011900 120S1090E 15 1321011906 120S1080E 15 1321011912 125S1064E 20 1321011918 127S1047E 20 1321012000 129S1028E 25 1321012006 128S1009E 25 1321012012 128S 995E 30 1321012018 124S 985E 30 1321012100 124S 977E 35 1321012106 126S 974E 35 1321012112 129S 974E 35 1321012118 130S 974E 35 1321012200 131S 973E 35 1321012206 132S 973E 35 1321012212 133S 973E 35 1321012218 137S 972E 35 1321012300 140S 971E 35 1321012306 144S 975E 35 1321012312 148S 976E 35 1321012318 153S 977E 30 1321012400 158S 974E 30 1321012406 161S 966E 30 1321012412 162S 963E 30 1321012418 164S 961E 30 1321012500 166S 959E 35 1321012506 172S 959E 35 1321012512 177S 958E 35 1321012518 182S 954E 35 1321012600 186S 949E 35 1321012606 189S 945E 35 1321012612 193S 941E 35 1321012618 195S 932E 35 1321012700 195S 918E 35 NNNN