WTIO30 FMEE 100019



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 27/4/20162017

1.A SEVERE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/10 AT 0000 UTC:

WITHIN 30 NM RADIUS OF POINT 26.2 S / 56.0 E

(TWENTY SIX    DECIMAL TWO   DEGREES SOUTH AND FIFTY SIX    DECIMAL

ZERO   DEGREES EAST)

MOVEMENT : SOUTH-EAST 12 KT



3.A DVORAK ANALYSIS: 3.0/3.5/W 0.5/12 H



4.A CENTRAL PRESSURE: 983 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: 260 SE: 190 SW: 150 NW: 70

34 KT NE: 150 SE: 110 SW: 90 NW: 60

48 KT NE: 60 SE: 60 SW: 50 NW: 0





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 600 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/10 12 UTC: 28.2 S / 58.4 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

24H: 2017/02/11 00 UTC: 29.5 S / 61.7 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

36H: 2017/02/11 12 UTC: 30.5 S / 64.7 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

48H: 2017/02/12 00 UTC: 31.1 S / 65.4 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

60H: 2017/02/12 12 UTC: 31.0 S / 65.0 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

72H: 2017/02/13 00 UTC: 31.1 S / 64.5 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/14 00 UTC: 32.1 S / 63.6 E, MAX WIND=030 KT, LOW

120H: 2017/02/15 00 UTC: 33.0 S / 63.3 E, MAX WIND=025 KT, LOW



2.C ADDITIONAL INFORMATION:

T=3.0 CI=3.5



OVER THE PAST SIX HOURS, CLOUD PATTERN REMAINED SIMILAR. A CIRRUS BOW

IS VISIBLE ON INFRARED DATA, CONFIRMING THE INCREASE OF WESTERLY

VERTICAL WIND SHEAR (25KT ACCORDING TO CIMSS AT 18Z). EVEN IF CARLOS

SEEMS TO RESIST THIS CONSTRAINT THANKS TO ITS ACCELERATION TO THE

SOUTH-EAST, 1735Z ASCAT SWATH SHOW A LOSS OF SYMMETRY IN THE SURFACE

CIRCULATION.



CARLOS KEEPS ON GOING SOUTH-EAST STEERED BY A MID-TROPOSPHERIC RIDGE

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

SATURDAY, CARLOS SHOULD BE BLOCKED BY A HIGH CELL CIRCULATING

EASTWARDS IN ITS SOUTH. THE MODEL GUIDANCE IS IN RATHER GOOD

AGREEMENT. FOR THE LONG RANGE, AS CARLOS SHOULD MAKE A U-TURN, THE

UNCERTAINTY BECOMES GREATER, EVEN IF THERE IS A GLOBAL CONSENSUS FOR

A SOUTH-WESTWARD TRACK.



TOMORROW, THE GROWING VWS AND THEN THE BAROCLINIC INTERACTION WITH AN

UPPER LEVEL TROUGH COMING FROM THE SOUTH-WEST, SHOULD GIVE

POST-TROPICAL CHARACTERISTICS TO THE SYSTEM. THIS WEEK-END, MODEL

GUIDANCE SUGGEST THAT CARLOS MAY SHIFT UNDER A CUT-OFF LOW. PROTECTED

FROM THE ENVIRONMENTAL SHEAR, BEFORE THE END OF ITS TRANSITION,

CARLOS MAY REGAIN ITS TROPICAL CHARACTERISTICS. HOWEVER, THE WEAK

OCEANIC POTENTIAL UNDERNEATH SOUTH OF 30S, IS LIKELY TO WEAKEN THE

CIRCULATION.=