WTXS31 PGTW 080300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 25S (IMAN) WARNING NR 002// RMKS/ 1. TROPICAL CYCLONE 25S (IMAN) WARNING NR 002 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 080000Z --- NEAR 24.9S 59.0E MOVEMENT PAST SIX HOURS - 120 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT REPEAT POSIT: 24.9S 59.0E --- FORECASTS: 12 HRS, VALID AT: 081200Z --- 26.2S 60.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 11 KTS --- 24 HRS, VALID AT: 090000Z --- 27.9S 62.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 150 DEG/ 09 KTS --- 36 HRS, VALID AT: 091200Z --- 29.5S 63.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT --- REMARKS: 080300Z POSITION NEAR 25.2S 59.5E. 08MAR21. TROPICAL CYCLONE 25S (IMAN), LOCATED APPROXIMATELY 334 NM SOUTHEAST OF ST DENIS, HAS TRACKED EAST-SOUTHEASTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT SATELLITE FIXES FROM PGTW AND FMEE AND A 080007Z 37 GHZ SSMIS PASS. THE INTENSITY OF 45 KNOTS IS CONSISTENT WITH A CONSENSUS OF SUBJECTIVE DVORAK FIXES FROM PGTW, FMEE AND FIMP AND A 072330Z CIMSS AUTOMATED DVORAK ESTIMATE OF 49 KNOTS. TC 25S IS TRACKING EAST- SOUTHEASTWARD IN THE GRADIENT BETWEEN SUBTROPICAL RIDGING TO THE NORTHEAST AND AN APPROACHING, DEEP-LAYER TROUGH TO THE SOUTHWEST. THE SYSTEM WILL CONTINUE TRACKING GENERALLY SOUTHEASTWARD OVER THE NEXT 36 HOURS AND COMPLETE EXTRATROPICAL TRANSITION AS THE APPROACHING TROUGH OVERTAKES THE SYSTEM. VERY STRONG (GREATER THAN 30 KNOTS) NORTHWESTERLY VERTICAL WIND SHEAR IS DISPLACING DEEP CONVECTION TO THE SOUTHEAST OF THE LOW-LEVEL CIRCULATION CENTER. HOWEVER, STRONG POLEWARD UPPER-LEVEL OUTFLOW AND PASSAGE OVER WARM WATER (SST ABOUT 27C) ARE SUPPORTING STORM INTENSITY DESPITE THE NOTED SHEAR. SLOW, BUT STEADY, WEAKENING IS EXPECTED DURING THE 36 HOUR FORECAST PERIOD UNDER THE ONGOING, COMPETING INFLUENCES OF STRONG VERTICAL WIND SHEAR, PASSAGE OVER COOLER WATER AND FAVORABLE UPPER-LEVEL DIFFLUENCE. NUMERICAL MODEL GUIDANCE IS IN EXCELLENT AGREEMENT REGARDING THE FORECAST TRACK, WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 080000Z IS 20 FEET. NEXT WARNINGS AT 081500Z AND 090300Z. REFER TO TROPICAL CYCLONE 24S (HABANA) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.// NNNN