WTIO30 FMEE 160706



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 21/8/20152016

1.A INTENSE TROPICAL CYCLONE  8  (FANTALA)



2.A POSITION 2016/04/16 AT 0600 UTC:

WITHIN 20 NM RADIUS OF POINT 12.2 S / 56.4 E

(TWELVE    DECIMAL TWO   DEGREES SOUTH AND FIFTY SIX    DECIMAL FOUR

DEGREES EAST)

MOVEMENT : WEST 8 KT



3.A DVORAK ANALYSIS: 6.0/6.0/D 1.0/6 H



4.A CENTRAL PRESSURE: 940 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 105 KT

RADIUS OF MAXIMUM WINDS (RMW) :15 KM



6.A EXTENSION OF WIND BY QUADRANTS (KM):

28 KT NE: 140 SE: 310 SW: 220 NW: 130

34 KT NE: 100 SE: 150 SW: 130 NW: 90

48 KT NE: 60 SE: 70 SW: 70 NW: 60

64 KT NE: 50 SE: 50 SW: 50 NW: 50



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2016/04/16 18 UTC: 11.8 S / 54.7 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

24H: 2016/04/17 06 UTC: 11.1 S / 52.8 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

36H: 2016/04/17 18 UTC: 10.1 S / 51.3 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE

48H: 2016/04/18 06 UTC: 9.5 S / 50.4 E, MAX WIND=095 KT, INTENSE

TROPICAL CYCLONE

60H: 2016/04/18 18 UTC: 9.7 S / 49.9 E, MAX WIND=085 KT, TROPICAL

CYCLONE

72H: 2016/04/19 06 UTC: 10.0 S / 50.0 E, MAX WIND=075 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2016/04/20 06 UTC: 11.7 S / 52.5 E, MAX WIND=070 KT, TROPICAL

CYCLONE

120H: 2016/04/21 06 UTC: 13.7 S / 55.1 E, MAX WIND=070 KT, TROPICAL

CYCLONE



2.C ADDITIONAL INFORMATION:

T=6.0-,CI=6.0+



THE EYE PATTERN OF FANTALA IS AGAIN IMPROVING SINCE 03Z WITH A

WARMING EYE WITHIN A VERY COLD CDO. RAW DT IS AT 6.5 AT 0630Z BUT 3

HOURS MEAN DT IS AT 5.9 AT 06Z. THE NORTH-WESTERLY CONSTRAINT IS

WEAKENING (JUST BELOW 10 KT ACCORDING TO CIMSS DATA) AND THIS MAY

CONTINUE TODAY AS THE SYSTEM SHOULD MOVE THROUGH AN AREA OF LOWER

WINDSHEAR TO ITS NORTH-WEST.



THE MEAN BEARING OVER THE LAST 3 HOURS IS 280AO JUST NORTH OF DUE

WEST. THE SYSTEM KEEPS ON TRACKING OVER THE NORTHERN SIDE OF A HIGH

GEOPOTENTIAL CELL LOCATED SOUTH OF MADAGASCAR, WITH A RIDGE AXIS OVER

MADAGASCAR. THIS RIDGE AXIS SHOULD MAINTAIN TO THE SOUTH-WEST OF

FANTALA WITHIN THE NEXT 48 HOURS AND THEREFORE SHOULD GRADUALLY BEND

THE TRACK NORTHWESTWARD.

ON THIS TRACK, FANTALA IS NOW A SERIOUS THREAT FOR THE SEYCHELLES

FARQUAHR ISLANDS (THE SOUTHERN GROUP MAINLY) WITH A POTENTIAL DIRECT

HIT WITHIN THE NEXT 36 HOURS (RARE EVENT - LAST ONE IS BONDO IN DEC

2006 AND NO OCCURENCE KNOWN SINCE THE BEGINNING OF THE SATELLITE ERA)



FROM SUNDAY, THE SOUTHERN HIGH PRESSURE SHOULD WEAKEN. MONDAY, THE

STEERING FLOW IS LIKELY TO FAIL. TUESDAY, A NEAR EQUATORIAL RIDGE IN

THE NORTH-EAST WILL REBUILT AND FANTALA COULD ADOPT A SOUTH-EASTWARD

TRACK. THE CURRENT TRACK FORECAST IS BASED ON A CONSENSUS OF THE LAST

AURO AND GFS OUTPUT (INCLUDING THE EARLY OUTPUTS FROM 00Z OF THE

EURO).



THE INTENSITY FORECAST IS DIFFICULT DUE TO THE SMALL SIZE OF THE

SYSTEM. THE INTENSITY FLUCTUATES RAPIDLY WITH SMALL FLUCTUATIONS OF

THE ENVIRONMENTAL CONDITIONS.

FROM MONDAY, ON THE SOUTH-EASTWARD TRACK, THE OHC COULD BECOME THE

MAIN FACTOR OF THE WEAKENING OF THE SYSTEM.=