WTIO30 FMEE 151238 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 24/5/20142015 1.A INTENSE TROPICAL CYCLONE 5 (BANSI) 2.A POSITION 2015/01/15 AT 1200 UTC: WITHIN 10 NM RADIUS OF POINT 17.9 S / 61.5 E (SEVENTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY ONE DECIMAL FIVE DEGREES EAST) MOVEMENT : EAST 7 KT 3.A DVORAK ANALYSIS: 5.0/6.0/W 1.0/6 H 4.A CENTRAL PRESSURE: 940 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 100 KT RADIUS OF MAXIMUM WINDS (RMW) :41 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 410 SE: 650 SW: 350 NW: 460 34 KT NE: 280 SE: 260 SW: 220 NW: 280 48 KT NE: 190 SE: 190 SW: 170 NW: 200 64 KT NE: 130 SE: 130 SW: 130 NW: 130 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 1300 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2015/01/16 00 UTC: 18.8 S / 63.6 E, MAX WIND=105 KT, INTENSE TROPICAL CYCLONE 24H: 2015/01/16 12 UTC: 20.4 S / 65.5 E, MAX WIND=100 KT, INTENSE TROPICAL CYCLONE 36H: 2015/01/17 00 UTC: 22.2 S / 67.2 E, MAX WIND=095 KT, INTENSE TROPICAL CYCLONE 48H: 2015/01/17 12 UTC: 23.5 S / 69.3 E, MAX WIND=090 KT, INTENSE TROPICAL CYCLONE 60H: 2015/01/18 00 UTC: 24.3 S / 71.8 E, MAX WIND=080 KT, TROPICAL CYCLONE 72H: 2015/01/18 12 UTC: 24.7 S / 74.3 E, MAX WIND=070 KT, TROPICAL CYCLONE 2.B LONGER-RANGE OUTLOOK : 96H: 2015/01/19 12 UTC: 25.4 S / 78.8 E, MAX WIND=050 KT, POST-TROPICAL DEPRESSION 120H: 2015/01/20 12 UTC: 27.0 S / 80.1 E, MAX WIND=040 KT, POST-TROPICAL DEPRESSION 2.C ADDITIONAL INFORMATIONS: T=5.0+ CI=6.0 DURING THE PAST 6H, EYEWALL HAS SHRUNK BUT DEEP CONVECTION HAS WARMED UP. THEREFORE, T NUMBER HAS TEMPORALLY DECREASED. BANSI HAS TRACKED EASTWARD FOR FEW HOURS BUT IT SHOULD RAPIDLY MOVE EAST-SOUTHEASTWARD AGAIN. THE CLOSEST POINT APPROACH TO RODRIQUES ISLAND IS FORECASTED AT ABOUT 70 KM AT THE END OF THE NEXT NIGHT. BANSI IS FORECAST TO ACCELERATE PROGRESSIVELY ON THIS TRACK, UNDER THE STEERING INFLUENCE OF A NEAR EQUATORIAL RIDGE AND OF A RIDGE BUILDING EASTWARD, IN THE MID TO HIGH LEVELS. THE AVAILABLE NWP MODELS ARE IN TIGHT GOOD AGREEMENT FOR THIS TRACK GENERALLY EAST-SOUTH-EASTWARD AND A SLOWER MOVEMENT AT THE END OF THE FORECAST RANGE. ON THIS TRACK, THE SYSTEM SHOULD KEEP ON WITH FAVORABLE UPPER LEVEL ENVIRONMENT FOR THIS NIGHT, WITH LOW VERTICAL WINDSHEAR, AND GOOD POLEWARD OUTFLOW. ON FRIDAY, BANSI SHOULD PROGRESS SOUTH OF THE UPPER LEVEL RIDGE AXIS, AND AN UPPER LEVEL TROUGH SHOULD COME CLOSER THE SYSTEM FROM THE SOUTH-WEST. THE UPPER LEVEL WESTERLY WINDSHEAR SHOULD INCREASE. OWING TO THE LOWERING OF THE OCEANIC HEAT POTENTIAL ON THE SYSTEM TRACK ROUND 25S, BANSI IS LIKELY TO BECOME A POST-TROPICAL HYBRID SYSTEM FROM SUNDAY. HOWEVER, THE MAXIMUM WIND SPEED IS LIKELY TO REMAIN STRONG WITHIN THE LOW LEVEL CIRCULATION. ----------------------------------- NUMERICAL STORM SURGE SIMULATIONS : FOR RODRIGUES ISLAND : 1M50 TO 2M50, MAINLY ON THE SOUTHERN AND EASTERN COASTS, DEPENDING ON THE FINAL TRACK, NEAR THE ISLAND. NOTE THAT THIS STORM SURGE FORECAST IS TO TAKE WITH CAUTION AND DOES NOT TAKE IN ACCOUNT THE ADDITIONAL SUBMERSION EFFECTS DUE TO THE CYCLONIC SWELL AND THE ASTRONOMIC TIDE. THEREFORE, THE INHABITANTS OF RODRIQUES ISLAND (INCREASING THREAT WITH SEVERE WEATHER CONDITIONS FOR THE NEXT NIGHT) SHOULD CLOSELY MONITOR THE PROGRESS OF THIS DANGEROUS SYSTEM.=