WTIO30 FMEE 080013



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 19/4/20162017

1.A MODERATE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/08 AT 0000 UTC:

WITHIN 20 NM RADIUS OF POINT 21.6 S / 53.4 E

(TWENTY ONE    DECIMAL SIX   DEGREES SOUTH AND FIFTY THREE    DECIMAL

FOUR   DEGREES EAST)

MOVEMENT : SOUTH-WEST 9 KT



3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/6 H



4.A CENTRAL PRESSURE: 996 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: 110 SE: 370 SW: 370 NW: 110

34 KT NE: 70 SE: 90 SW: 90 NW: 70







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 800 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/08 12 UTC: 22.6 S / 52.5 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

24H: 2017/02/09 00 UTC: 23.3 S / 52.3 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

36H: 2017/02/09 12 UTC: 24.3 S / 52.9 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

48H: 2017/02/10 00 UTC: 25.5 S / 54.1 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

60H: 2017/02/10 12 UTC: 26.5 S / 56.1 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

72H: 2017/02/11 00 UTC: 27.4 S / 58.0 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/12 00 UTC: 28.6 S / 60.1 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

120H: 2017/02/13 00 UTC: 29.9 S / 59.9 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=CI=3.0-



SINCE A FEW HOURS, DEEP CONVECTION HAS REBUILT OVER THE CENTER,

ASSOCIATED WITH A STRONG THUNDERSTORM ACTIVITY.

THE CENTER IS LOCATED THANKS TO RADAR DATA OF LA REUNION.

THUS, THE UPPER CONSTRAINT HAS CLEARLY WEAKENED AND IS EVALUATED LEES

THAN 10KT IN THE LAST CIMSS ESTIMATES.



CARLOS GOES ON TRACKING SOUTH-WESTWARD. FROM TOMORROW, UNDER THE

GROWING INFLUENCE OF A MID-TROPOSPHERIC RIDGE IN THE NORTH-EAST AND A

SURFACE TROUGH IN THE SOUTH COMING FROM THE MID-LATITUDES, CARLOS'

TRACK SHOULD BEND SOUTHWARD THEN SOUTH-EASTWARD.

STARTING ON FRIDAY, THERE IS A LARGE SPEED DISPERSION IN THE

SOUTH-EATSWRDS TRACKS. SATURDAY, AT THE END OF THE TAUS, ENSEMBLE

PREDICTION DATA SHOW A STRONG UNCERTAINTY ON CARLOS' TRACK. FOR NOW,

THE DETERMNISTIC MODELS ARE IN RATHER GOOD AGREEMENT TO FORECAST A

NEW SOUTH-WESTWARD TURN STEERED BY A HIGH PRESSURE CELL CENTERED IN

THE SOUTH-EAST.



THE UPPER DIVERGENCE REMAINS STRONG IN THE SOUTH-EASTERN QUADRANT OF

CARLOS. THUS, A INTENSIFICATION WINDOW STILL EXISTS UNTIL TOMORROW

NIGHT WITH A BUILDING POLAR OUTFLOW CHANEL. FROM THURSDAY, CARLOS

SHOULD TRACK AHEAD OF AN UPPER TROUGH COMING FROM THE MID-LATITUDES.

AT FIRST, CARLOS' SOUTH-EASTWARD TRACK SHOULD MITIGATE THE INFLUENCE

OF THE MODERATE WESTERLY SHEAR. BY SATURDAY, THE SHEAR SHOULD BE TOO

STRONG AND CARLOS SHOULD BEGIN TO WEAKEN. FURTHER MORE, THE PROXIMITY

OF THE UPPER TROUGH COULD BEGIN TO TRIGGER AN EXTRATROPICALISATION

PHASE.=