WTIO30 FMEE 111213 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 28/13/20142015 1.A TROPICAL CYCLONE 13 (JOALANE) 2.A POSITION 2015/04/11 AT 1200 UTC: WITHIN 15 NM RADIUS OF POINT 22.0 S / 67.8 E (TWENTY TWO DECIMAL ZERO DEGREES SOUTH AND SIXTY SEVEN DECIMAL EIGHT DEGREES EAST) MOVEMENT : SOUTH 9 KT 3.A DVORAK ANALYSIS: 4.0/4.5/W 0.5/6 H 4.A CENTRAL PRESSURE: 970 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 70 KT RADIUS OF MAXIMUM WINDS (RMW) :46 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 330 SE: 350 SW: 480 NW: 260 34 KT NE: 240 SE: 280 SW: 280 NW: 200 48 KT NE: 150 SE: 160 SW: 170 NW: 170 64 KT NE: 80 SE: 80 SW: 80 NW: 80 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1100 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2015/04/12 00 UTC: 24.4 S / 67.6 E, MAX WIND=065 KT, TROPICAL CYCLONE 24H: 2015/04/12 12 UTC: 26.5 S / 67.1 E, MAX WIND=055 KT, SEVERE TROPICAL STORM 36H: 2015/04/13 00 UTC: 27.9 S / 65.8 E, MAX WIND=055 KT, POST-TROPICAL DEPRESSION 48H: 2015/04/13 12 UTC: 29.1 S / 65.4 E, MAX WIND=050 KT, POST-TROPICAL DEPRESSION 60H: 2015/04/14 00 UTC: 31.0 S / 66.5 E, MAX WIND=050 KT, POST-TROPICAL DEPRESSION 72H: 2015/04/14 12 UTC: 33.5 S / 68.5 E, MAX WIND=045 KT, POST-TROPICAL DEPRESSION 2.B LONGER-RANGE OUTLOOK : 96H: 2015/04/15 12 UTC: 35.3 S / 72.1 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM 120H: 2015/04/16 12 UTC: 36.4 S / 76.9 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM 2.C ADDITIONAL INFORMATIONS: T=4.0 CI=4.5 THE MULTISPECTRAL SATELLITE IMAGERY DEPICTS A SLOW WARMING TREND OF THE CLOUDS TOP DURING THE PAST SIX HOURS, WITH AN ALLONGATED EYE, AND CIRRUS ARCS APPEAR AS SIGNS OF A NORTH-WESTERLY CONSTRAINT. THE MW PICTURE AT 0431Z THEN 0947Z CONFIRM A BREAK IN THE EYEWALL IN THE NORTHERN SEMI-CERCLE. THE ENVIRONMENT OF JOALANE IS GOING TO DEGRADE AS JOALANE TRACKS CLOSER TO THE WESTERLY SUBTROPICAL JET. THE SYSTEM IS THEREFORE EXPECTED TO SLOWLY WEAKEN WITHIN THE NEXT 24 HOURS( THE FAST SOUTHWARD TRACK SHOULD IN A FIRST TIME ATTENUATE ITS IMPACT). JOALANE IS EXPECTED TO LOSE ITS PURELY TROPICAL CHARACTERISTICS TOMORROW OVER MARGINAL HEAT OCEANIC CONTENT AND PENETRATING IN A BAROCLINIC ENVIRONMENT. THE SYSTEM IS HOWEVER EXPECTED TO REMAIN POWERFUL AS STORM FORCE WINDS SHOULD LAST FOR SEVERAL DAYS ONCE THE SYSTEM WILL BECOME A POST-TROP CYCLONE. THE END OF THE EXTRATROP PROCESS IS ONLY FORECAST AT THE END OF THE PERIOD AS THE THE SYSTEM SHOULD GRADUALLY BE EMBEDDED WITHIN THE MID-LAT WESTERLIES. BEFORE THAT TIME, THE POLEWARDS TRACK OF JOALANE WILL BE TEMPORARILY BLOCKED MONDAY BY A BUILDING BUT TRANSIENT SUBTROPICAL RIDGE.=