WTIO30 FMEE 091848



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 9/12/20142015

1.A MODERATE TROPICAL STORM  12  (HALIBA)



2.A POSITION 2015/03/09 AT 1800 UTC:

WITHIN 20 NM RADIUS OF POINT 22.4 S / 55.6 E

(TWENTY TWO    DECIMAL FOUR   DEGREES SOUTH AND FIFTY FIVE    DECIMAL

SIX   DEGREES EAST)

MOVEMENT : SOUTH-EAST 8 KT



3.A DVORAK ANALYSIS: 2.0/2.5/W 1.0/12 H



4.A CENTRAL PRESSURE: 995 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT

RADIUS OF MAXIMUM WINDS (RMW) :37 KM



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

28 KT NE: 240 SE: 190 SW: 90 NW: 70

34 KT NE: 40 SE: 60 SW: 40 NW: 40







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2015/03/10 06 UTC: 23.5 S / 56.4 E, MAX WIND=030 KT, TROPICAL

DEPRESSION

24H: 2015/03/10 18 UTC: 24.1 S / 56.9 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION

36H: 2015/03/11 06 UTC: 24.5 S / 57.6 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION

48H: 2015/03/11 18 UTC: 25.2 S / 58.6 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION

60H: 2015/03/12 06 UTC: 26.6 S / 60.5 E, MAX WIND=035 KT,

EXTRATROPICAL SYSTEM

72H: 2015/03/12 18 UTC: 27.8 S / 62.9 E, MAX WIND=035 KT,

EXTRATROPICAL SYSTEM



2.B LONGER-RANGE OUTLOOK :

96H: 2015/03/13 18 UTC: 31.6 S / 70.8 E, MAX WIND=040 KT,

EXTRATROPICAL SYSTEM

120H: 2015/03/14 18 UTC: 34.7 S / 77.2 E, MAX WIND=040 KT,

EXTRATROPICAL SYSTEM



2.C ADDITIONAL INFORMATIONS:

T=2.0 AND CI=2.5+.



HALIBA HAS WEAKENED, THE LAST ASCAT DATA 1735Z SHOW THE STRONGEST

WINDS IN THE SOUTHERN SEMI-CERCLE.

CLOUD PATTERN HAD RAPIDLY DETERIORATE AT THE END OF THE AFTERNON, AS

THE SYSTEM EXPERIENCES A SEVERE IMPACT OF THE WEST-NORTH-WESTERLY

VERTICAL WINDSHEAR, BUT DEEP CONVECTION SEEM TO REBUILD IN THE LAST

HOURS.



THE SYSTEM IS EXPECTED TO KEEP ON TRACKING GLOBALLY SOUTH-EASTWARDS

WITHIN A WEST TO WESTERLY STEERING FLOW DRIVEN BY THE LOW TO

MID-LEVEL NEAR EQUATORIAL HIGHS.



TUESDAY, THE SYSTEM SHOULD SLOW DOWN AND EXPERIENCING BY THAT TIME

SOME DEEP STRUCTURE CHANGES WITH A LARGER AND MORE ASYMMETRICAL WIND

FIELDS SUGGESTING THAT THE SYSTEM MAY LOOSE ITS PURE TROPICAL

CHARACTERISTICS.



THURSDAY, THE SYSTEM SHOULD RESUME ITS SOUTHEASTWARDS TRACK WITH THE

END OF  EXTRATROP PROCESS.



GIVEN THE ONGOING AND EXPECTED IMPACT OF THIS SYSTEM OVER PORTIONS OF

THE MASCARENES ISLANDS, INHABITANT OF THIS AREA SHOULD STILL MONITOR

THE PROGRESS OF THIS SYSTEM.=