WTIO30 FMEE 150629



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 17/8/20152016

1.A INTENSE TROPICAL CYCLONE  8  (FANTALA)



2.A POSITION 2016/04/15 AT 0600 UTC:

WITHIN 15 NM RADIUS OF POINT 12.3 S / 59.6 E

(TWELVE    DECIMAL THREE   DEGREES SOUTH AND FIFTY NINE    DECIMAL

SIX   DEGREES EAST)

MOVEMENT : WEST 10 KT



3.A DVORAK ANALYSIS: 5.5/5.5/D 1.0/12 H



4.A CENTRAL PRESSURE: 954 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 95 KT

RADIUS OF MAXIMUM WINDS (RMW) :28 KM



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

28 KT NE: 130 SE: 220 SW: 200 NW: 130

34 KT NE: 110 SE: 170 SW: 150 NW: 90

48 KT NE: 80 SE: 110 SW: 100 NW: 70

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



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 400 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2016/04/15 18 UTC: 12.2 S / 58.0 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE

24H: 2016/04/16 06 UTC: 11.9 S / 56.6 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

36H: 2016/04/16 18 UTC: 11.5 S / 55.2 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

48H: 2016/04/17 06 UTC: 10.9 S / 54.0 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

60H: 2016/04/17 18 UTC: 10.4 S / 53.1 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

72H: 2016/04/18 06 UTC: 10.0 S / 52.7 E, MAX WIND=095 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2016/04/19 06 UTC: 11.1 S / 54.5 E, MAX WIND=065 KT, TROPICAL

CYCLONE

120H: 2016/04/20 06 UTC: 13.4 S / 57.5 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=CI=5.5+





DURING THE LAST 6 HOURS, CLOUD PATTERN IMPROVED WITH THE RETURN OF AN

EYE ON SATELLITE IMAGERY, SURROUNDED BY COLD CLOUD TOPS. LAST

MICROWAVE DATA CONFIRMS THAT, SHOWING A DEEP CONVECTION RING ALL

AROUND THE WARM SPOT. THEREFORE, THE SYSTEM INTENSITY IS RAISED TO

INTENSE TROPICAL CYCLONE LEVEL. NORTH-NORTH-EASTERLY WIND SHEAR

ANALYSED BY THE CIMSS AT 00Z AROUND 12KT, DOES NOT SEEM TO IMPACT

FANTALA ANYMORE, WHICH STILL BENEFITS FROM AN EXCELLENT UPPER

POLARSIDE DIVERGENCE



THE SYSTEM KEEPS ON TRACKING WESTWARD ON THE NORTHERN SIDE OF A HIGH

GEOPOTENTIAL CELL LOCATED BETWEEN MADAGASCAR AND THE MASCAREIGNES

ISLANDS. FRIDAY, THE GRADUAL STRENGTHENING OF THIS HIGH SHOULD

ORIENTATE THE TRACK A BIT MORE NORTHWESTWARD. ON SATURDAY, FANTALA IS

FORECASTED TO TRANSIT A LITTLE LESS THAN 100 NM SOUTH OF AGALEGA AT

THE STAGE OF INTENSE TROPICAL CYCLONE.

FROM SUNDAY, THE SYSTEM SHOULD BE SLOWED BY A RIDGE IN ITS WEST AND

AXED OVER THE MOZAMBIQUE CHANNEL, AS THE HIGH CENTERED OVER THE

MASCAREIGNES WEAKENS. MONDAY, THE NEAR EQUATORIAL RIDGE IN THE

NORTH-EAST WILL TAKE OVER THE STEERING FLOW AND DRIVE A SHARP

SOUTH-EASTWARD U-TURN OF THE SYSTEM. THE MOST RELIABLE NWP MODELS ARE

IN AGREEMENT AND STILL FORECAST A NARROW CLOCKWISE LOOP. HOWEVER, THE

EXACT LOCATION OF THE TURN REMAINS UNCERTAIN AS THE 12Z ECMWF

ENSEMBLE PREDICTION RUN FORECAST A MODERATE RISK THAT FANTALA CROSS

THE FARQHAR BEFORE DOING ITS TURN WEST OF THESE ISLANDS. HOWEVER

AMONG THE DETERMINISTICS NO RELIABLE MODEL GUIDANCE SUGGEST THE

CROSSING OF THE CENTER IN THE ARCHIPELAGO.



UP TO TUESDAY, FANTALA IS LIKELY TO UNDERGO RATHER CONDUCIVE UPPER

LEVEL ENVIRONMENT. THE NORTHERLY CONSTRAINT SHOULD REMAIN MARGINAL

WHILE POLAR SIDE DIVERGENCE IS EXPECTED TO INCREASE SUNDAY AFTER A

TEMPORARY DECAY SATURDAY. BUT, WEST OF 55E, THE LESSER OCEAN HEAT

CONTENT SHOULD BECOME THE LIMITING FACTOR FOR THE INTENSITY OF THE

SYSTEM. ITS INFLUENCE WILL BE ALL THE MORE IMPORTANT IF FANTALA SLOWS

DOWN AND RETURN ON ITS PREVIOUS TRACK WHERE WATERS ARE COLDER.

WEDNESDAY, A UPPER AND MID LEVELS TROUGH ARRIVES FROM THE SOUTH-WEST

AND MAY INDUCE A MODERATE NORTH-WESTERLY UPPER LEVEL CONSTRAINT.=