WTIO30 FMEE 170613 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 25/8/20152016 1.A INTENSE TROPICAL CYCLONE 8 (FANTALA) 2.A POSITION 2016/04/17 AT 0600 UTC: WITHIN 10 NM RADIUS OF POINT 10.6 S / 52.6 E (TEN DECIMAL SIX DEGREES SOUTH AND FIFTY TWO DECIMAL SIX DEGREES EAST) MOVEMENT : WEST-NORTH-WEST 10 KT 3.A DVORAK ANALYSIS: 6.0/6.0/W 0.5/18 H 4.A CENTRAL PRESSURE: 939 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 105 KT RADIUS OF MAXIMUM WINDS (RMW) :17 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 120 SE: 300 SW: 370 NW: 120 34 KT NE: 90 SE: 170 SW: 190 NW: 90 48 KT NE: 60 SE: 90 SW: 90 NW: 60 64 KT NE: 50 SE: 60 SW: 60 NW: 50 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 300 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2016/04/17 18 UTC: 10.0 S / 51.2 E, MAX WIND=110 KT, INTENSE TROPICAL CYCLONE 24H: 2016/04/18 06 UTC: 9.5 S / 50.0 E, MAX WIND=115 KT, INTENSE TROPICAL CYCLONE 36H: 2016/04/18 18 UTC: 9.6 S / 49.7 E, MAX WIND=100 KT, INTENSE TROPICAL CYCLONE 48H: 2016/04/19 06 UTC: 9.8 S / 49.9 E, MAX WIND=080 KT, TROPICAL CYCLONE 60H: 2016/04/19 18 UTC: 10.5 S / 51.0 E, MAX WIND=090 KT, INTENSE TROPICAL CYCLONE 72H: 2016/04/20 06 UTC: 11.5 S / 52.3 E, MAX WIND=100 KT, INTENSE TROPICAL CYCLONE 2.B LONGER-RANGE OUTLOOK : 96H: 2016/04/21 06 UTC: 14.0 S / 54.3 E, MAX WIND=080 KT, TROPICAL CYCLONE 120H: 2016/04/22 06 UTC: 15.7 S / 56.1 E, MAX WIND=060 KT, SEVERE TROPICAL STORM 2.C ADDITIONAL INFORMATION: T=CI=6.0+ OVER THE LAST SIX HOURS, FANTALA INTENSITY HAS BEEN LITTLE CHANGE EVEN IF THE LAST INFRARED IMAGERIES SHOW A CLEAR TOP CLOUDS COOLING. FANTALA MOVES CLOSER DANGEROUSLY TO FARQUAHR ARCHIPELAGO. FANTALA IS FORESCASTED TO CROSS OVER THE ARCHIPELAGO DURING THE FIRST PART OF THE NIGHT TO THE STAGE OF INTENSE TROPICAL CYCLONE. ASSOCIATED TO GUSTS AROUND 300 KM/H THE STORM SURGE SHOULD REACH 2 METERS LOCALLY, ESPECIALLY CLOSER TO THE CORE. THE SYSTEM CONTINUES ITS NORTHWESTWARDS TRACK OVER THE NORTHERN AND NORTHEASTERN SIDE OF A HIGH GEOPOTENTIAL CELL LOCATED SOUTH OF MADAGASCAR, WITH A RIDGE AXIS OVER MADAGASCAR. TODAY AND TOMOROW, THIS RIDGE AXIS SHOULD SHIFT PROGRESSIVELY EASTWARD AND LEAVE ROOM FOR A MID-LATITUDE TROUGH. FANTALA SHOULD BE CENTRED WITHIN A COL WITH CONTRARY STEERING FLOWS. SO, FANTALA IS FORESCASTED TO BEGIN TO SLOW DOWN THIS NIGHT WHEN IT SHOULD TRANSIT CLOSER THE FARQUAHR ISLAND. TUESDAY, FANTALA SHOULD STOP ITS NORSTWESTWARD TRACK AND BEGIN A SLOW ABOUT-TURN TOWARD THE SOUTHEAST UNDER THE NORTHEASTERN STEERING FLOW OF A BUILDING MID-LEVEL NEAR-EQUATORIAL RIDGE. FROM WEDNESDAY, FANTALA SHOULD KEEP ON ITS SOUTHEASTWARD TRAJECTORY UNDER THE TWICE INFLUENCE OF THE NEAR-EQUATORIAL RIDGE LOCATED TO THE NORTH-EAST AND AHEAD A WIDE MID-LATITUDE TROUGH. THE INTENSITY FORECAST IS DIFFICULT DUE TO THE SMALL SIZE OF THE SYSTEM. THE INTENSITY FLUCTUATES RAPIDLY WITH SMALL FLUCTUATIONS OF THE ENVIRONMENTAL CONDITIONS. WITHOUT ANY EARLY INDICATIONS OF THE BEGINNING OF AN ERC AND GIVEN THE EXPECTED IMPROVEMENT OF THE UPPER LEVEL DIVERGENCE WITHIN THE NEXT 24 HOURS, FANTALA IS LIKELY TO DEEPEN SLOWLY. FROM MONDAY, ON THE SOUTH-EASTWARD TRACK, THE SELF INDUCED SST COOLING COULD BECOME THE MAIN FACTOR OF THE WEAKENING OF THE SYSTEM AS ATMOSPHERIC FACTORS ARE EXPECTED TO BE EXCELLENT. WEDNESDAY, WITH THE ARRIVAL OF THE AFOREMENTIONED TROUGH, THE UPPER LEVEL CONDITIONS SHOULD PROGRESSIVELY DETERIORATE WITH AN INCREASING NORTHWESTWARD VERTICAL WIND SHEAR. FANTALA SHOULD BEGIN A WEAKENING PHASE MORE SIGNIFICANTLY.=