WTXS31 PGTW 191500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 13S (URIAH) WARNING NR 013// RMKS/ 1. TROPICAL CYCLONE 13S (URIAH) 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: 191200Z --- NEAR 24.9S 77.8E MOVEMENT PAST SIX HOURS - 235 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT REPEAT POSIT: 24.9S 77.8E --- FORECASTS: 12 HRS, VALID AT: 200000Z --- 25.0S 77.5E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 240 DEG/ 02 KTS --- 24 HRS, VALID AT: 201200Z --- 25.2S 77.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 180 DEG/ 03 KTS --- 36 HRS, VALID AT: 210000Z --- 25.7S 77.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 48 HR POSIT: 160 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 211200Z --- 26.5S 77.4E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 191500Z POSITION NEAR 24.9S 77.7E. TROPICAL CYCLONE (TC) 13S (URIAH), LOCATED APPROXIMATELY 1110 NM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A WELL-DEFINED, EXPOSED LOW-LEVEL CIRCULATION CENTER WITH LIMITED DEEP CONVECTION SHEARED TO THE SOUTH. HOWEVER, A 191051Z SSMIS 91GHZ COLOR COMPOSITE IMAGE SHOWS TIGHTLY-WRAPPED SHALLOW BANDING WRAPPING INTO A DEFINED CENTER, WHICH SUPPORTS THE CURRENT POSITION WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT 50 KNOTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 45 TO 55 KNOTS. THIS IS CLEARLY SUPPORTED BY BOTH THE LOW-LEVEL CONVECTIVE STRUCTURE AND A 190435Z ASCAT IMAGE SHOWING NUMEROUS 50-KNOT WIND VECTORS. TC 13S, HOWEVER, IS FORECAST TO GRADUALLY WEAKEN AS IT DRIFTS SLOWLY SOUTHWESTWARD TO SOUTHWARD OVER THE NEXT TWO DAYS DUE TO COOLER SST AND PERSISTENT MODERATE TO STRONG VERTICAL WIND SHEAR. TC 13S IS EXPECTED TO MAINTAIN SLOW TRACK SPEEDS DUE TO THE PRESENCE OF A LOW-LEVEL RIDGE TO THE SOUTH, WHICH IS EFFECTIVELY BLOCKING ITS SOUTHWARD PROGRESSION. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT AND SUPPORTS THE JTWC TRACK WITH HIGH CONFIDENCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 191200Z IS 20 FEET. NEXT WARNINGS AT 200300Z AND 201500Z.//