WTIO30 FMEE 090134 CCA

***************CORRECTIVE**************



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 23/4/20162017

1.A SEVERE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/09 AT 0000 UTC:

WITHIN 20 NM RADIUS OF POINT 23.4 S / 53.2 E

(TWENTY THREE    DECIMAL FOUR   DEGREES SOUTH AND FIFTY THREE

DECIMAL TWO   DEGREES EAST)

MOVEMENT : SOUTH-EAST 5 KT



3.A DVORAK ANALYSIS: 4.0/4.0/D 1.0/12 H



4.A CENTRAL PRESSURE: 980 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT

RADIUS OF MAXIMUM WINDS (RMW) :28 KM



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

28 KT NE: 120 SE: 180 SW: 140 NW: 70

34 KT NE: 90 SE: 110 SW: 50 NW: 40

48 KT NE: 50 SE: 60 SW: 50 NW: 30





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/09 12 UTC: 24.8 S / 54.1 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

24H: 2017/02/10 00 UTC: 26.4 S / 55.3 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

36H: 2017/02/10 12 UTC: 28.4 S / 57.7 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

48H: 2017/02/11 00 UTC: 29.6 S / 60.6 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

60H: 2017/02/11 12 UTC: 29.7 S / 63.0 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION

72H: 2017/02/12 00 UTC: 30.4 S / 63.8 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/13 00 UTC: 30.3 S / 62.0 E, MAX WIND=035 KT, SUBTROPICAL

DEPRESSION

120H: 2017/02/14 00 UTC: 30.3 S / 60.5 E, MAX WIND=040 KT,

SUBTROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=CI=4.0-



OVER THE PAST HOURS, CONVECTION REMAINED STRONG NEAR THE CENTER. ON

THE LAST IR IMAGES, A WARMER POINT HAS TEMPORARILY APPEARED. 2307

SSMI SWATH STILL DEPICTS A VERY TIGHT RING OF INTENSE CONVECTION, BUT

LACKING ITS WESTERN PART. ACCORDING TO CIMSS LATEST ANALYSIS, THE

VERTICAL WINDSHEAR IS INCREASING SLIGHTLY BUT REMAINS CURRENTLY WEAK.



DURING THE NEXT HOURS, CARLOS IS EXPECTED TO KEEP ON ACCELERATING

TOWARDS THE SOUTH-EAST, STEERED BY A MID-TROPOSPHERIC RIDGE IN THE

NORTH-EAST AND A TROUGH COMING FROM THE MID-LATITUDES. FROM SUNDAY,

CARLOS SHOULD BE BLOCKED BY A HIGH CELL CIRCULATING EASTWARDS IN ITS

SOUTH. THE MODEL GUIDANCE IS IN RATHER GOOD AGREEMENT EVEN IF THE GFS

MODEL REMAINS QUICKER THAN THE ECMWF ONE FRIDAY AND SATURDAY. AT THE

END OF THE TAUS, AS CARLOS SHOULD MAKE A U-TURN, THE UNCERTAINTY

BECOMES GREATER.



THE INFLUENCE OF AN UPPER TROUGH COMING FROM THE SOUTH-WEST SHOULD

GRADUALLY BECOME SIGNIFICANT TODAY. AT FIRST, THE DIVERGENCE AND

CARLOS SOUTH-EASTWARD MOVEMENT TOWARDS THE SOUTH-EAST SHOULD MITIGATE

THE EFFECTS OF THE MODERATE WESTERLY SHEAR. BUT BY FRIDAY, IT SHOULD

QUICKLY BECOME TOO STRONG, ESPECIALLY WITH THE SMALL SIZE OF CARLOS,

AS A MID-TROPOSPHERIC DRY AIR LAYER COULD ALSO SLITHER IN ITS CORE.

THE SYSTEM SHOULD THEN WEAKEN. DURING THE WEEK-END, CARLOS COULD

SHIFT UNDER THE UPPER TROUGH WHICH THEN ISOLATE ITSELF AS A CUT-OFF

LOW ABOVE THE CIRCULATION, SHIELDING IT FROM THE SHEAR. IN THIS

CONTEXT, CARLOS MAY BECOME A SUBTROPICAL SYSTEM AT THE END OF THE

TAUS, AND EVEN SLIGHTLY INTENSIFY AGAIN OVER LOW OHC WATERS.=