WTXS31 PGTW 280300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 015// RMKS/ 1. TROPICAL CYCLONE 13S (THIRTEEN) WARNING NR 015 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 280000Z --- NEAR 18.9S 87.4E MOVEMENT PAST SIX HOURS - 280 DEGREES AT 13 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 18.9S 87.4E --- FORECASTS: 12 HRS, VALID AT: 281200Z --- 18.5S 83.7E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 280300Z POSITION NEAR 18.8S 86.5E. 28JAN21. TROPICAL CYCLONE 13S (THIRTEEN), LOCATED APPROXIMATELY 925 SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A RAGGED AND FULLY EXPOSED LOW LEVEL CIRCULATION (LLC) WITH THE ASSOCIATED WEAK, FLARING CONVECTION SHEARED 130NM+ TO THE SOUTHEAST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE LLC IN THE MSI LOOP THAT LINED UP WELL WITH THE WEAK BUT DISCERNIBLE LLC FEATURE IN THE 272212Z SSMIS MICROWAVE IMAGE. THE INITIAL INTENSITY OF 25KTS IS BASED ON THE SATCON ADT ESTIMATE OF 25KTS AND IS CONSISTENT WITH THE DEGRADED EIR SATELLITE CONVECTIVE SIGNATURE. UPPER LEVEL ANALYSIS INDICATES THE CYCLONE IS UNDER 25KT+ OF RELATIVE VERTICAL WIND SHEAR AS THE STORM MOTION HAS BECOME 90DEG OUT-OF-PHASE WITH THE UPPER LEVEL WIND FLOW. ADDITIONALLY, OUTFLOW IS BEING SUPPRESSED BY THE SHORTWAVE TROUGH TO THE SOUTHWEST. TC 13S HAS FALLEN TO BELOW THE JTWC WARNING INTENSITY CRITERIA OF 35KTS AND IS NOT EXPECTED TO RECOVER. THE REMNANTS WILL PROPAGATE WEST- NORTHWESTWARD THROUGH A HOSTILE ENVIRONMENT. HOWEVER, BY TAU 72, AS IT DRIFTS INTO WARMER SST (28C), THERE IS A POSSIBILITY OF REGENERATION. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280000Z IS 10 FEET.// NNNN