WTXS31 PGTW 260300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 011// RMKS/ 1. TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 011 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 260000Z --- NEAR 18.3S 94.6E MOVEMENT PAST SIX HOURS - 260 DEGREES AT 06 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 - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT REPEAT POSIT: 18.3S 94.6E --- FORECASTS: 12 HRS, VALID AT: 261200Z --- 18.4S 93.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 270 DEG/ 07 KTS --- 24 HRS, VALID AT: 270000Z --- 18.4S 92.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 275 DEG/ 10 KTS --- 36 HRS, VALID AT: 271200Z --- 18.2S 89.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 280 DEG/ 12 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 280000Z --- 17.7S 87.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 285 DEG/ 13 KTS --- 72 HRS, VALID AT: 290000Z --- 16.4S 82.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 15 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 300000Z --- 15.7S 76.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 275 DEG/ 16 KTS --- 120 HRS, VALID AT: 310000Z --- 14.8S 69.5E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT --- REMARKS: 260300Z POSITION NEAR 18.3S 94.3E. 26JAN21. TROPICAL CYCLONE 13S (THIRTEEN), LOCATED APPROXIMATELY 1450 NM EAST-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES THAT CONVECTION HAS WEAKENED SIGNIFICANTLY, BUT REMAINS ENTRENCHED TO THE SOUTH OF THE PARTIALLY EXPOSED LOW- LEVEL CIRCULATION CENTER (LLCC). ANALYSIS OF THE EXPOSED LOW-LEVEL BANDING FEATURES WRAPPING INTO THE WELL-DEFINED LLCC PROVIDES HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED WITH MODERATE CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T2.0 (30 KTS) IN LIGHT OF AN ADT ESTIMATE OF T3.1 AND SATCON ESTIMATE OF 47 KNOTS. THE SYSTEM LIES UNDER AN UPPER-LEVEL RIDGE AXIS WHICH IS PROVIDING LOW (5-10 KT) VWS AND STRONG POLEWARD AND MODERATE EQUATORWARD OUTFLOW. SSTS HOWEVER ARE MARGINAL AS THE SYSTEM IS MOVING ROUGHLY ALONG THE 26-27 DEG C ISOTHERM. THE STEERING ENVIRONMENT IS CURRENTLY IN THE PROCESS OF CHANGING, WITH A DEVELOPING MID-LEVEL STR TO THE SOUTH BECOMING THE PREDOMINATE STEERING FEATURE, AS EVIDENCED BY THE SLOW TURN WESTWARD OVER THE PREVIOUS TWELVE HOURS. THE STR TO THE SOUTH IS FORECAST TO BE THE PRIMARY STEERING MECHANISM THROUGH THE DURATION OF THE FORECAST PERIOD. THE OVERALL ENVIRONMENT IS EXPECTED TO BE MARGINAL THROUGH TAU 48, WITH UPPER-LEVEL CONVERGENCE DEVELOPING AFTER TAU 12 AS THE SYSTEM MOVES AWAY FROM THE UPPER-LEVEL RIDGE AXIS. INTENSITY WILL REMAIN FLAT, WITH SOME DIURNALLY DRIVEN EXCURSIONS BOTH HIGHER AND LOWER, THROUGH TAU 48. SOME MINOR INTENSIFICATION IS EXPECTED BY TAU 72 AS THE SYSTEM MOVES OVER WARMER WATERS AND UPPER-LEVEL OUTFLOW IMPROVES. NUMERICAL MODEL GUIDANCE IS GOOD AGREEMENT THROUGH THE DURATION OF THE FORECAST PERIOD, WITH A 110NM SPREAD AT TAU 48, INCREASING TO 160NM AT TAU 120, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 260000Z IS 13 FEET. NEXT WARNINGS AT 261500Z AND 270300Z.// NNNN