WTIO30 FMEE 171920 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 33/5/20142015 1.A TROPICAL CYCLONE 5 (BANSI) 2.A POSITION 2015/01/17 AT 1800 UTC: WITHIN 30 NM RADIUS OF POINT 24.5 S / 71.5 E (TWENTY FOUR DECIMAL FIVE DEGREES SOUTH AND SEVENTY ONE DECIMAL FIVE DEGREES EAST) MOVEMENT : EAST-SOUTH-EAST 15 KT 3.A DVORAK ANALYSIS: 4.0/4.5/D 0.5/12 H 4.A CENTRAL PRESSURE: 956 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 70 KT RADIUS OF MAXIMUM WINDS (RMW) :59 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 720 SE: 740 SW: 960 NW: 410 34 KT NE: 330 SE: 480 SW: 440 NW: 260 48 KT NE: 180 SE: 130 SW: 130 NW: 110 64 KT NE: 100 SE: 100 SW: 100 NW: 0 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1001 HPA / 1100 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2015/01/18 06 UTC: 25.4 S / 75.2 E, MAX WIND=060 KT, SEVERE TROPICAL STORM 24H: 2015/01/18 18 UTC: 26.5 S / 80.7 E, MAX WIND=050 KT, POST-TROPICAL DEPRESSION 36H: 2015/01/19 06 UTC: 29.6 S / 86.1 E, MAX WIND=050 KT, POST-TROPICAL DEPRESSION 48H: 2015/01/19 18 UTC: 32.0 S / 88.7 E, MAX WIND=040 KT, POST-TROPICAL DEPRESSION 60H: 2015/01/20 06 UTC: 33.4 S / 91.7 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM 72H: 2015/01/20 18 UTC: 33.6 S / 93.7 E, MAX WIND=030 KT, LOW 2.B LONGER-RANGE OUTLOOK : 2.C ADDITIONAL INFORMATIONS: T=4.0+ AND CI=4.5+ AN INTERMITTENT WARM SPOT WAS SEEN ON IR IMAGERY. THE CURRENT POSITION IS BASED ON IR IMAGERY JUST TO THE WEST OF THE WARM SPOT TO TAKE INTO ACCOUNT THE VERTICAL TILT OF THE STRUCTURE DUE TO THE SHEAR AS SEEN ON MW IMAGERY. THE CURRENT INTENSITY ASSESSEMENT IS ON THE LOW SIDE OF ALL THE DVORAK ESTIMATES THAT RANGES FROM 70 TO 90 KT. SATCON IS AT 90-95 KT (1 MIN WINDS). AN SSMIS INTENSITY ESTIMATE AT 1148Z IS AT 71 KT (1 MIN WINDS). TOMORROW, BANSI WILL REMAIN ON A EAST-SOUTH-EAST TRACK UNDER THE STEERING FLOW OF THE HIGH PRESSURE IN ITS NORTH-EAST AND ITS NORTH IN THE MID AND THE HIGH LEVELS. ON THIS PATH, THE UPPER LEVEL WESTERLY WINDSHEAR, AND THE LOWERING OF THE OCEANIC HEAT POTENTIAL ABOUT 25S, WILL BECOME MORE AND MORE UNFAVOURABLE TO THE SYSTEM. BANSI SHOULD ADOPT HYBRID POST-TROPICAL FEATURES ON SUNDAY. FROM MONDAY, IT SHOULD TRACK SOUTH-EASTWARD UNDER THE INFLUENCE OF A TROUGH SOUTHWARD, AND BEGIN ITS EXTRATROPICAL TRANSITION. ON TUESDAY, THE LOW LEVEL CIRCULATION IS LIKELY TO MERGE WITH THE MID-LATITUDES TROUGH AND THE REMNANT SYSTEM IS LIKELY TO ACHIEVE ITS EXTRATROPICAL TRANSITION. THE WIND SPEED ARE FORECAST TO REMAIN STRONG WITHIN THE LLC UP TO MONDAY.THE REMNANT LOW SHOULD FILL UP ON WEDNESDAY.=