WTIO30 FMEE 231813 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 17/1/20152016 1.A MODERATE TROPICAL STORM 1 (ANNABELLE) 2.A POSITION 2015/11/23 AT 1800 UTC: WITHIN 30 NM RADIUS OF POINT 17.8 S / 77.6 E (SEVENTEEN DECIMAL EIGHT DEGREES SOUTH AND SEVENTY SEVEN DECIMAL SIX DEGREES EAST) MOVEMENT : SOUTH-EAST 18 KT 3.A DVORAK ANALYSIS: 3.0/4.0/W 1.0/12 H 4.A CENTRAL PRESSURE: 989 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT RADIUS OF MAXIMUM WINDS (RMW) :28 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 260 SE: 280 SW: 200 NW: 140 34 KT NE: 60 SE: 130 SW: 130 NW: 60 48 KT NE: 0 SE: 60 SW: 60 NW: 0 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2015/11/24 06 UTC: 20.5 S / 79.6 E, MAX WIND=045 KT, POST-TROPICAL DEPRESSION 24H: 2015/11/24 18 UTC: 22.9 S / 80.4 E, MAX WIND=035 KT, POST-TROPICAL DEPRESSION 36H: 2015/11/25 06 UTC: 23.9 S / 80.7 E, MAX WIND=030 KT, POST-TROPICAL DEPRESSION 48H: 2015/11/25 18 UTC: 24.8 S / 80.1 E, MAX WIND=025 KT, LOW 60H: 2015/11/26 06 UTC: 24.9 S / 78.8 E, MAX WIND=025 KT, LOW 72H: 2015/11/26 18 UTC: 24.6 S / 77.3 E, MAX WIND=025 KT, LOW 2.B LONGER-RANGE OUTLOOK : 2.C ADDITIONAL INFORMATION: FT=3.0 CI=4.0- LATEST MICROWAVE DATA (SSMIS AT 1135Z) SHOWS THAT THE INNER CORE CONTINUES TO DETERIORATE DUE TO THE DUAL INFLUENCE OF INCREASING NORTHWESTERLY SHEAR (NEAR 35 KT AT 12Z ACCORDING CIMSS DATA) AND COOLER SST. THE NWP MODELS REMAINS IN TIGHT AGREEMENT FOR A SOUTHEASTWARDS MOVEMENT TOWARDS A LARGE MID-TROPOSPHERIC TROUGH. ON THIS TRACK AND WITH THE EXPECTED INTERACTION TONIGHT WITH AN UPPER LEVEL TROUGH LOCATED TO THE SOUTH-WEST OF THE STORM SHOULD BRING SOME BAROCLINIC CONDITIONS WITHIN THE SYSTEM. THEREFORE, ANNABELLE IS EXPECTED TO GAIN SOME HYBRID CHARACTERISTICS AND BECOME POST-TROPICAL TONIGHT OR TUESDAY MORNING FROM WEDNESDAY AND BEYOND, AS THE UPPER TROUGH SHOULD SHIFT EASTWARDS, THE WESTERLY VERTICAL WINDSHEAR WILL BECOME VERY UNFAVORABLE, AND THE LLCC IS LIKELY TO FILL UP RAPIDLY. THE TRACK OF THE RESIDUAL LOW SHOULD BEND WESTWARDS THURSDAY, BETWEEN 20S AND 25S, STEERED BY THE SUBTROPICAL RIDGE.=