WTXS31 PGTW 082100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 03S (AVA) WARNING NR 025// RMKS/ 1. TROPICAL CYCLONE 03S (AVA) WARNING NR 025 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 081800Z --- NEAR 27.3S 46.8E MOVEMENT PAST SIX HOURS - 250 DEGREES AT 14 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 215 NM SOUTHEAST QUADRANT 205 NM SOUTHWEST QUADRANT 180 NM NORTHWEST QUADRANT REPEAT POSIT: 27.3S 46.8E --- FORECASTS: 12 HRS, VALID AT: 090600Z --- 28.7S 46.7E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 205 NM NORTHEAST QUADRANT 195 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 15 KTS --- 24 HRS, VALID AT: 091800Z --- 31.0S 49.0E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 195 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 175 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 135 DEG/ 20 KTS --- 36 HRS, VALID AT: 100600Z --- 33.7S 52.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 210 NM NORTHEAST QUADRANT 215 NM SOUTHEAST QUADRANT 205 NM SOUTHWEST QUADRANT 215 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 27 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 101800Z --- 37.3S 57.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 290 NM NORTHEAST QUADRANT 210 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 290 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 140 DEG/ 32 KTS --- 72 HRS, VALID AT: 111800Z --- 46.2S 69.7E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 490 NM NORTHEAST QUADRANT 440 NM SOUTHEAST QUADRANT 285 NM SOUTHWEST QUADRANT 450 NM NORTHWEST QUADRANT --- REMARKS: 082100Z POSITION NEAR 27.7S 46.8E. TROPICAL CYCLONE 03S (AVA), LOCATED APPROXIMATELY 472 NM SOUTHEAST OF EUROPA ISLAND, HAS TRACKED WEST-SOUTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH WEAK FLARING CONVECTION SHEARED TO THE EAST. THE INITIAL POSITION IS BASED ON A 081200Z METEOSAT-8 INFRARED SATELLITE IMAGE DEPICTING THE PARTIALLY EXPOSED LLCC. THE INITIAL INTENSITY OF 40 KNOTS IS HEDGED ABOVE THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T1.5 (25 KTS) AND BELOW A RECENT SATCON ESTIMATE OF 50 KNOTS. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (10 TO 15 KNOT) VERTICAL WIND SHEAR VALUES BEING OFFSET BY COOL (25 CELSIUS) SEA SURFACE TEMPERATURES. UPPER LEVEL ANALYSIS SHOWS THAT THE SYSTEM STILL HAS STRONG POLEWARD OUTFLOW HOWEVER, THE EQUATORWARD OUTFLOW HAS WEAKENED SIGNIFICANTLY. TC 03S WILL INITIALLY TRACK SOUTHEAST ALONG THE NORTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE SOUTHEAST. PRIOR TO TAU 12, THE TRACK WILL SHIFT TO THE SOUTH AS THE SYSTEM BEGINS TO INTERACT WTIH A DEEP MID-LATITUDE SHORTWAVE TROUGH AND TRACK SOUTHEASTWARD WHILE GRADUALLY WEAKENING. THE MID-LATITUDE TROUGH WILL CAUSE AN INCREASE IN VERTICAL WIND SHEAR AND THE SYSTEM WILL CONTINUE TO TRACK SOUTH THROUGH COOLER SEA SURFACE TEMPERATURES WHICH WILL CONTRIBUTE TO THE WEAKENING TREND. TC 03S IS FORECAST TO BEGIN EXTRA- TROPICAL TRANSITION (ETT) BY TAU 48 AND WILL COMPLETE ETT BY TAU 72. DYNAMIC MODEL GUIDANCE IS NOW IN FAIR AGREEMENT; HOWEVER, THE INITIAL TRACK DIRECTION TO THE SOUTHEAST WAS NOT PREDICTED IN THE MODEL SOLUTION. DUE TO THE INACCURATE PREDICTION OF THE SYSTEMS INITIAL DIRECTION THERE IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 081800Z IS 15 FEET. NEXT WARNINGS AT 090300Z, 090900Z, 091500Z AND 092100Z. REFER TO TROPICAL CYCLONE 04S (IRVING) WARNINGS (WTXS32 PGTW) FOR SIX- HOURLY UPDATES.//