WTIO30 FMEE 071838



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 13/13/20142015

1.A TROPICAL CYCLONE  13  (JOALANE)



2.A POSITION 2015/04/07 AT 1800 UTC:

WITHIN 30 NM RADIUS OF POINT 14.6 S / 63.1 E

(FOURTEEN    DECIMAL SIX   DEGREES SOUTH AND SIXTY THREE    DECIMAL

ONE   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-EAST 5 KT



3.A DVORAK ANALYSIS: 5.0/5.0/D 1.5/12 H



4.A CENTRAL PRESSURE: 976 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 80 KT

RADIUS OF MAXIMUM WINDS (RMW) :43 KM



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

28 KT NE: 140 SE: 190 SW: 190 NW: 140

34 KT NE: 120 SE: 160 SW: 160 NW: 120

48 KT NE: 90 SE: 110 SW: 110 NW: 90

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



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 1000 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : UNKNOWN



1.B FORECASTS:

12H: 2015/04/08 06 UTC: 15.3 S / 63.5 E, MAX WIND=090 KT, INTENSE

TROPICAL CYCLONE

24H: 2015/04/08 18 UTC: 16.1 S / 63.7 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE

36H: 2015/04/09 06 UTC: 17.0 S / 63.9 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

48H: 2015/04/09 18 UTC: 18.1 S / 64.4 E, MAX WIND=115 KT, INTENSE

TROPICAL CYCLONE

60H: 2015/04/10 06 UTC: 19.1 S / 65.2 E, MAX WIND=115 KT, INTENSE

TROPICAL CYCLONE

72H: 2015/04/10 18 UTC: 20.0 S / 66.0 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2015/04/11 18 UTC: 23.3 S / 67.6 E, MAX WIND=065 KT, TROPICAL

CYCLONE

120H: 2015/04/12 18 UTC: 27.4 S / 67.4 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM



2.C ADDITIONAL INFORMATIONS:

T=5.0- AND CI=5.0+

JOALANE HAS CLEARLY INTENSIFIED OVER THE PAST 12 HOURS.

IT SHOWS HOWEVER SINCE 1700Z AN ELONGATED AND RATHER RAGGED EYE.

NEAR GALE FORCE WINDS EXTENSION HAS BEEN REDUCED THANKS TO 1737Z

ASCAT SWATH AND MSLP HAS BEEN THEREFORE RE-CALCULATED.



SYSTEM IS EXPECTED TO KEEPS ON TRACKING SLOWLY SOUTH-SOUTH-EASTWARDS

WITHIN THE NEXT 24/36H IN RELATIONSHIP WITH A MID-LEVEL RIDGE

EXISTING IN ITS SOUTH.

THIS AFOREMENTIONED RIDGE IS EXPECTED TO PROGRESSIVELY WEAKEN AS A

COL TAKE ITS PLACE.

JOALANE SHOULD THEN PROGRESSIVELY ACCELERATE SOUTH-SOUTH-EASTWARDS

THEN SOUTHWARDS FROM SATURDAY.



ON THIS FORECAST TRACK, ENVIRONMENTAL CONDITIONS ARE EXPECTED TO KEEP

ON IMPROVING AS THE SYSTEM IS SHIFTING UNDER THE UPPER LEVEL RIDGE

AXIS.

TOMORROW WEDNESDAY, AN UPPER LEVEL OUTFLOW CHANNEL SHOULD TAKE PLACE

POLEWARD AND SHOULD BE EFFICIENT UP TO FRIDAY.

FROM FRIDAY LATE OR SATURDAY EARLY, SYSTEM IS EXPECTED TO WEAKEN AS

IT EXPERIENCE THE DOUBLE CONSTRAINTS OF STRENGTHENING  NORTH-WESTERLY

UPPER LEVEL WINDS AND MARGINAL HEAT OCEANIC CONTENT SOUTH OF 21S.



JOALANE KEEPS ON REPRESENTING A SERIOUS THREAT FOR RODRIGUES ISLAND.=