WTXS32 PGTW 100300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04S (IRVING) WARNING NR 017// RMKS/ 1. TROPICAL CYCLONE 04S (IRVING) WARNING NR 017 03 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 100000Z --- NEAR 25.5S 69.3E MOVEMENT PAST SIX HOURS - 215 DEGREES AT 19 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 095 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 135 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 210 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 25.5S 69.3E --- FORECASTS: 12 HRS, VALID AT: 101200Z --- 29.9S 68.6E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 200 NM NORTHEAST QUADRANT 225 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 160 DEG/ 30 KTS --- 24 HRS, VALID AT: 110000Z --- 35.5S 70.9E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 195 NM NORTHEAST QUADRANT 200 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 155 DEG/ 38 KTS --- 36 HRS, VALID AT: 111200Z --- 42.4S 75.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 265 NM NORTHEAST QUADRANT 215 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 240 NM NORTHWEST QUADRANT --- REMARKS: 100300Z POSITION NEAR 26.6S 69.1E. TROPICAL CYCLONE 04S (IRVING), LOCATED APPROXIMATELY 738 NM EAST- SOUTHEAST OF PORT LOUIS, MAURITIU, HAS TRACKED SOUTHWESTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DISSIPATING CONVECTION IN THE SOUTHERN SEMI-CIRCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY EXPOSED LLCC AND A 092302Z 91GHZ SSMIS MICROWAVE IMAGE. THE AFOREMENTIONED MICROWAVE IMAGE DEPICTS THAT REMAINING CONVECTION IS LOCATED IN THE SOUTHERN SEMICIRCLE AND IS SHEARED AROUND 100 NM FROM THE LLCC. THE INITIAL INTENSITY IS ASSESSED AT 60 KNOTS, SLIGHTLY BELOW A DVORAK CURRENT INTENSITY ESTIMATE OF T4.0 (65 KNOTS) FROM PGTW BASED ON THE WEAKENING NATURE OF THE SYSTEM. ENVIRONMENTAL ANALYSIS REVEALS THAT THE SYSTEM IS IN AN AREA OF MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR AND IS TRACKING THROUGH AN AREA OF COOLER (25-26 CELSIUS) SEA SURFACE TEMPERATURES. UPPER LEVEL ANALYSIS SHOWS THAT THE SYSTEM HAS A STRONG POLEWARD OUTFLOW CHANNEL AND NO EQUATORWARD OUTLFOW. TC 04S IS CURRENTLY TRACKING SOUTHWESTWARD ALONG THE WESTERN EXTENT OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST. THE SYSTEM IS FORECAST TO TRACK TO THE SOUTH THROUGH TAU 12 AS IT ROUNDS THE RIDGE AXIS. AFTER TAU 12 THE SYSTEM WILL RAPIDLY ACCELERATE TO THE SOUTHEAST. AFTER TAU 24, THE SYSTEM WILL BEGIN TO INTERACT WITH AN APPROACHING TOUGH WHICH WILL INTRODUCE HIGHER VERTICAL WIND SHEAR WHICH, COMBINED WITH COOLER SEA SURFACE TEMPERATURES WILL WEAKEN THE SYSTEM AND BEGIN THE EXTRA-TROPICAL TRANSITION PROCESS. TC IRVING IS FORECAST TO COMPLETE THE TRANSITION BY TAU 36. DYNAMIC MODEL GUIDANCE IS IN TIGHT AGREEMENT LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 100000Z IS 25 FEET. NEXT WARNINGS AT 100900Z, 101500Z, 102100Z AND 110300Z. REFER TO TROPICAL CYCLONE 03S (AVA) WARNING (WTXS31 PGTW) FOR THE FINAL WARNING ON THIS SYSTEM. REFER TO TROPICAL CYCLONE 05S (FIVE) WARNINGS (WTXS33 PGTW) FOR SIX-HOURLY UPDATES.//