WTIO30 FMEE 051223



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 14/6/20172018

1.A TROPICAL CYCLONE  6  (DUMAZILE)



2.A POSITION 2018/03/05 AT 1200 UTC:

WITHIN 20 NM RADIUS OF POINT 22.1 S / 51.7 E

(TWENTY TWO    DECIMAL ONE   DEGREES SOUTH AND FIFTY ONE    DECIMAL

SEVEN   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-EAST 10 KT



3.A DVORAK ANALYSIS: 5.0/5.5/W 0.5/6 H



4.A CENTRAL PRESSURE: 958 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 85 KT

RADIUS OF MAXIMUM WINDS (RMW) :56 KM



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

28 KT NE: 460 SE: 460 SW: 330 NW: 220

34 KT NE: 220 SE: 280 SW: 220 NW: 150

48 KT NE: 140 SE: 170 SW: 140 NW: 110

64 KT NE: 70 SE: 80 SW: 70 NW: 60



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 1100 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/03/06 00 UTC: 23.8 S / 52.3 E, MAX WIND=075 KT, TROPICAL

CYCLONE

24H: 2018/03/06 12 UTC: 25.2 S / 53.5 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

36H: 2018/03/07 00 UTC: 26.7 S / 54.6 E, MAX WIND=055 KT,

POST-TROPICAL DEPRESSION

48H: 2018/03/07 12 UTC: 28.2 S / 55.8 E, MAX WIND=050 KT,

POST-TROPICAL DEPRESSION

60H: 2018/03/08 00 UTC: 29.4 S / 57.2 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

72H: 2018/03/08 12 UTC: 31.2 S / 59.0 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2018/03/09 12 UTC: 39.4 S / 62.5 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION





2.C ADDITIONAL INFORMATION:

T=5.0+ CI=5.5-



THE BEST INFRARED IMAGERY PATTERN WAS OBSERVED DURING 0730Z AND 0930Z

BUT WITH ALWAYS AN ELONGATED AND RAGGED EYE. A LITTLE BEFORE, THE

0530Z GPM MICROWAVE SWATH SHOWED A SLIGHTLY IMPROVEMENT OF THE

INTERNAL STRUCTURE. BUT SINCE 0930Z, INFRARED IMAGERY PATTERN HAS

CLEARLY DETERIORATED.



THE SYSTEM IS EXPECTED TO KEEP ON ITS TRACK TOWARD THE SOUTHSOUTHEAST

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.



THE ARRIVAL OF AN UPPER TROUGH FROM THE WEST WILL DRIVE A

STRENGTHENING WESTERLY TO NORTHWESTERLY WINDSHEAR CONSTRAINT OVER THE

SYSTEM. THIS SIGNIFICANT DEGRADATION OF THE ENVIRONMENTAL CONDITIONS

SHOULD ACCENTUATE THE WEAKENING PHASE OF THE METEOR AND CONTINUE

TUESDAY AND WEDNESDAY. WITHIN A MORE AND MORE BAROCLINIC ENVIRONMENT

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

POST-TROPICAL TRANSITION FROM WEDNESDAY.=