WTIO30 FMEE 061922



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 9/13/20142015

1.A MODERATE TROPICAL STORM  13  (JOALANE)



2.A POSITION 2015/04/06 AT 1800 UTC:

WITHIN 30 NM RADIUS OF POINT 13.9 S / 61.9 E

(THIRTEEN    DECIMAL NINE   DEGREES SOUTH AND SIXTY ONE    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : NORTH-NORTH-WEST 4 KT



3.A DVORAK ANALYSIS: 2.5/2.5/D 0.5/24 H



4.A CENTRAL PRESSURE: 995 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT

RADIUS OF MAXIMUM WINDS (RMW) :32 KM



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

28 KT NE: 190 SE: 220 SW: 150 NW: 60

34 KT NE: 90 SE: 150 SW: 80 NW: 0







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1100 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2015/04/07 06 UTC: 14.4 S / 61.4 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

24H: 2015/04/07 18 UTC: 14.9 S / 61.1 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

36H: 2015/04/08 06 UTC: 15.4 S / 61.1 E, MAX WIND=075 KT, TROPICAL

CYCLONE

48H: 2015/04/08 18 UTC: 16.1 S / 61.4 E, MAX WIND=090 KT, INTENSE

TROPICAL CYCLONE

60H: 2015/04/09 06 UTC: 16.9 S / 61.9 E, MAX WIND=095 KT, INTENSE

TROPICAL CYCLONE

72H: 2015/04/09 18 UTC: 17.5 S / 62.5 E, MAX WIND=100 KT, INTENSE

TROPICAL CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2015/04/10 18 UTC: 19.4 S / 64.1 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE

120H: 2015/04/11 18 UTC: 21.9 S / 64.2 E, MAX WIND=110 KT, INTENSE

TROPICAL CYCLONE



2.C ADDITIONAL INFORMATIONS:

T=CI=2.5+



PREVIOUS POSITIONS RELOCATED FURTHER NORTH PER RECENT MW IMAGERY AND

SCATT DATA.



ON CLASSICAL IMAGERY (IR), THE CLOUD PATTERN IMPROVED SOMEWHAT

EARLIER THIS EVENING BUT RECENTLY SHOWN SIGNIFICANT FLUCTUATIONS

INDUCING MARGINAL IMPROVEMENT ON THE DVORAK ANALYSIS (GOOD AGREEMENT

AMONG THE 3 AGENCIES FOR A FT AT 2.5). HOWEVER MW IMAGERY (WINDSAT AT

1413Z) DEPICT AN EVIDENT IMPROVEMENT OF THE LOW LEVEL STRUCTURE THAT

SUGGEST THAT A RAPID INTENSIFICATION SPELL MAY BE POSSIBLE WTHIN THE

NEXT 24 TO 48 HOURS. THE INTENSITY AT 40 KT IS BASED ON 38 KT WINDS

READ NEAR THE RMW ON ASCAT-B OF 1758Z. THE SYSTEM HAS BEEN NAMED AT

17Z BY THE NWS OF MAURITIUS.



THE ENVIRONEMENTAL CONDITIONS AROUND JOALANE ARE RATHER FAVOURABLE :

THE LOW LEVEL CONVERGENCE IS GOOD POLEWARD. THE SYSTEM IS NORTH OF

THE UPPER LEVEL RIDGE, WITH GOOD EQUATORWARD DIVERGENCE. THE UPPER

LEVEL VWS IS WEAK, DIRECTION EAST-SOUTH-EAST AT ABOUT 10-15KT -CIMSS

AT 12Z - AND DO NOT SEEM TO DISTURB THE INTENSIFICATION PROCESS.



MAJOR CHANGES IN THE FORECAST TRACK: AT 12Z, THE 3 MOST RELIABLE

MODELS (GFS, EURO AND UKMO) ARE NOW ON A CLEAR BETTER AGREEMENT

TOWARDS A SOLUTION SHOWN BY GFS SINCE MANY RUNS NOW ... WITH A

SOUTHWARDS TURN THAT SHOULD OCCUR EAST OF 60E AND A SOUTWARDS TO

SOUTHEASTWARDS TRACK POTENTIALLY VERY DANGEROUS FOR RODRIGUES ISLAND

..



ATMOSPHERIC AND OCEANIC CONDITIONS APPEAR FAVOURABLE ... AND JOALANE

IS EXPECTED TO BECOME A POWERFULL AND DANGEROUS CYCLONE LATER THIS

WEEK .. THEREFORE, RODRIGUES UNHABITANTS SHOULD MONITOR THE PROGRESS

OF THIS SYSTEM.=