WTIO30 FMEE 060031



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 16/6/20172018

1.A TROPICAL CYCLONE  6  (DUMAZILE)



2.A POSITION 2018/03/06 AT 0000 UTC:

WITHIN 25 NM RADIUS OF POINT 23.5 S / 52.6 E

(TWENTY THREE    DECIMAL FIVE   DEGREES SOUTH AND FIFTY TWO

DECIMAL SIX   DEGREES EAST)

MOVEMENT : SOUTH-EAST 8 KT



3.A DVORAK ANALYSIS: 4.5/5.0/W 1.0/12 H



4.A CENTRAL PRESSURE: 954 HPA

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

RADIUS OF MAXIMUM WINDS (RMW) :46 KM



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

28 KT NE: 460 SE: 500 SW: 370 NW: 280

34 KT NE: 280 SE: 330 SW: 260 NW: 190

48 KT NE: 190 SE: 200 SW: 190 NW: 110

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



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 1200 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/03/06 12 UTC: 25.1 S / 53.9 E, MAX WIND=070 KT, TROPICAL

CYCLONE

24H: 2018/03/07 00 UTC: 26.6 S / 55.2 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

36H: 2018/03/07 12 UTC: 28.4 S / 56.1 E, MAX WIND=050 KT,

POST-TROPICAL DEPRESSION

48H: 2018/03/08 00 UTC: 29.6 S / 57.0 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

60H: 2018/03/08 12 UTC: 31.5 S / 59.5 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

72H: 2018/03/09 00 UTC: 35.9 S / 61.4 E, MAX WIND=050 KT,

EXTRATROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :







2.C ADDITIONAL INFORMATION:

T=4.5+ CI=5.0+



OVER THE LAST SIX HOURS, DUMAZILE CLOUD PATTERN BARELY EVOLVED, WITH

AN EMBEDDED CENTER. RAW DVORAK ANALYSIS ARE MOSTLY OSCILLATING

BETWEEN 4.5. IN ADDITION TO THE OBSERVED EVOLUTION IN MICROWAVE AND

IR IMAGERY, INTENSITY WAS DOWNGRADED TO 80KT. CENTRAL PRESSURE WAS

READJUSTED THANKS TO 5601501 BUOY DATA, THAT WAS LOCATED VERY CLOSE

TO THE CENTER. THE PRECISE POSITION OF THE CENTER IS UNCERTAIN DUE TO

THE LACK OF RELIABLE DATA. NORTH-WESTERLY VERTICAL WIND SHEA IS STILL

ANALYSED AROUND 15KT BY CIMSS AT 21Z.



THE SYSTEM IS EXPECTED TO KEEP ON ITS TRACK SOUTH-EASTWARD

CIRCUMVENTING THE MID-LEVEL RIDGE.THURSDAY EVENING, A MID-LATITUDES

TROUGH CIRCULATING IN THE SOUTH SHOULD ALLOW A QUICK EVACUATION. THE

MODEL DISPERSION REMAINS RATHER WEAK, WHICH GIVES A GOOD CONFIDENCE

IN THIS TRACK FORECAST. THE UNCERTAINTY INCREASES FOR THE END OF THE

FORECAST PERIOD, WHEN THE SYSTEM IS TAKEN AWAY BY THE MID-LATITUDES

WESTERLIES.



THIS MORNING, THE ARRIVAL OF AN UPPER TROUGH FROM THE WEST WILL DRIVE

THE STRENGTHENING WESTERLY TO NORTHWESTERLY UPPER CONSTRAINT. THIS

SIGNIFICANT DETERIORATION OF THE ENVIRONMENTAL CONDITIONS SHOULD

ACCELERATE THE WEAKENING. WITHIN A MORE AND MORE BAROCLINIC

ENVIRONMENT, OVER COOLER WATERS SOUTH OF 27S, THE SYSTEM SHOULD BEGIN

TO GAIN EXTRA-TROPICAL FEATURES FROM WEDNESDAY.=