WTIO30 FMEE 200042 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 36/8/20152016 1.A TROPICAL CYCLONE 8 (FANTALA) 2.A POSITION 2016/04/20 AT 0000 UTC: WITHIN 20 NM RADIUS OF POINT 10.0 S / 51.9 E (TEN DECIMAL ZERO DEGREES SOUTH AND FIFTY ONE DECIMAL NINE DEGREES EAST) MOVEMENT : EAST-SOUTH-EAST 7 KT 3.A DVORAK ANALYSIS: 5.0/5.0/D 1.0/6 H 4.A CENTRAL PRESSURE: 973 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 75 KT RADIUS OF MAXIMUM WINDS (RMW) :28 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 240 SE: 250 SW: 240 NW: 280 34 KT NE: 150 SE: 70 SW: 90 NW: 120 48 KT NE: 90 SE: 60 SW: 60 NW: 80 64 KT NE: 60 SE: 50 SW: 50 NW: 50 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 400 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2016/04/20 12 UTC: 10.9 S / 53.1 E, MAX WIND=070 KT, TROPICAL CYCLONE 24H: 2016/04/21 00 UTC: 11.9 S / 54.3 E, MAX WIND=060 KT, SEVERE TROPICAL STORM 36H: 2016/04/21 12 UTC: 12.6 S / 54.9 E, MAX WIND=050 KT, SEVERE TROPICAL STORM 48H: 2016/04/22 00 UTC: 13.0 S / 55.3 E, MAX WIND=040 KT, MODERATE TROPICAL STORM 60H: 2016/04/22 12 UTC: 13.1 S / 55.0 E, MAX WIND=040 KT, MODERATE TROPICAL STORM 72H: 2016/04/23 00 UTC: 12.6 S / 54.0 E, MAX WIND=040 KT, MODERATE TROPICAL STORM 2.B LONGER-RANGE OUTLOOK : 96H: 2016/04/24 00 UTC: 11.3 S / 52.0 E, MAX WIND=045 KT, MODERATE TROPICAL STORM 120H: 2016/04/25 00 UTC: 9.9 S / 49.5 E, MAX WIND=050 KT, SEVERE TROPICAL STORM 2.C ADDITIONAL INFORMATION: T=CI=5.0- DURING THE LAST 6 HOURS, THE CONVECTIVE RING HAS COOLED AGAIN, AND THE EYE IS WELL DEFINED. THE 3H AVERAGED DT HAS INCREASED AT 5.0-. FANTALA KEEPS ON TRACKING EAST-SOUTH-EASTWARD. THE UPPER LEVEL WINDSHEAR REMAINS WEAK (016AO/5KT ACCORDING TO THE CIMSS DATA). UNTIL THURSDAY, FANTALA'S TRACK WILL BE STEERED BY TWO ATMOSPHERIC PATTERNS : THE NEAR EQUATORIAL RIDGE BUILDING IN ITS NORTH-EAST AND A WIDE MID-LATITUDES TROUGH COMING FROM THE SOUTH-WEST. UNDER THIS DOUBLE INFLUENCE, THE PREDICTABILITY OF THE EAST-SOUTH-EASTWARD TRACK IS QUITE HIGH AND THE MODEL GUIDANCE IS THUS IN AGREEMENT. FROM THURSDAY EVENING, NONE OF THE AVAILABLE MODELS ALLOW FANTALA TO REACH THE TROUGH, WHICH IS AN EXIT DOOR TOWARDS THE MID-LATITUDES. A NEW HIGH GEOPOTENTIAL CELL FOLLOWING THE TROUGH IS FORECASTED TO SETTLE OVER SOUTH AF MADAGASCAR AND PROGRESSIVELY EXTEND NORTHWARD. FANTALA SHOULD SLOW AGAIN AND FRIDAY, IT COULD TRACK NORTH-WESTWARD, STEERED BY THIS WIDE RIDGE IN ITS SOUTH-WEST. THEN, UNTIL THE END OF THE FORECAST PERIOD, THE SYSTEM IS LIKELY TO BE STEERED BY THE HIGH SUBTROPICAL CELL IN THE LOW AND MID TROPOSPHERE, AND SHOULD KEEP ON A WEST-NORTH-WESTWARD TO NORTH-WESTWARD TRACK. THE LAST RUN OF AVNO IS NOW IN AGREEMENT WITH THE EUROPEAN MODEL, AND SUGGESTS A TRACK NORTH OF MADAGASCAR, THAT IS LIKELY TO PREVENT THE NORTH-EASTERN COAST FROM A LANDING. TOMORROW AFTERNOON, FANTALA SHOULD MOVE AGAIN ON ITS PREVIOUS TRACK AND THE ENEGERTIC CONDITIONS WILL DEGRADE, AND THE UPPER LEVEL ENVIRONMENTAL CONDITIONS SHOULD BECOME LESS CONDUCIVE WITH A WEAK TO MODERATE NORTHWESTERLY UPPER LEVEL WINDSHEAR. FROM SATURDAY OR SUNDAY, THE UPPER LEVEL CONDITIONS COULD IMPROVE SLIGHTLY. THUS, FANTALA'S INTENSITY IS LIKELY TO DECREASE UP TO FRIDAY, AND AFTER, REMAIN STEADY OR INCREASE SLIGHTLY DURING THE WEEK-END.=