WTIO30 FMEE 091839



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 26/4/20162017

1.A SEVERE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/09 AT 1800 UTC:

WITHIN 30 NM RADIUS OF POINT 25.1 S / 54.7 E

(TWENTY FIVE    DECIMAL ONE   DEGREES SOUTH AND FIFTY FOUR    DECIMAL

SEVEN   DEGREES EAST)

MOVEMENT : SOUTH-EAST 9 KT



3.A DVORAK ANALYSIS: 3.5/4.0/W 1.0/12 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: 200 SW: 130 NW: 90

34 KT NE: 150 SE: 130 SW: 70 NW: 60

48 KT NE: 60 SE: 60 SW: 40 NW: 30





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/10 06 UTC: 27.2 S / 56.9 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

24H: 2017/02/10 18 UTC: 28.6 S / 59.8 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

36H: 2017/02/11 06 UTC: 29.6 S / 62.9 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION

48H: 2017/02/11 18 UTC: 30.2 S / 64.3 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION

60H: 2017/02/12 06 UTC: 30.2 S / 64.1 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION

72H: 2017/02/12 18 UTC: 29.9 S / 63.4 E, MAX WIND=035 KT,

POST-TROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/13 18 UTC: 30.6 S / 62.2 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

120H: 2017/02/14 18 UTC: 31.8 S / 60.9 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=3.5 CI=4.0



OVER THE PAST SIX HOURS, CLOUD TOPS REMAINED QUITE COLD. THE CIRRUS

PLUME HAD BEEN REJETCED IN THE EASTERN PARTS, CONFIRMING THE

EXISTENCE OF A WEST-NORTH-WESTERLY UPPER CONSTRAINT (20KT ESTIMATED

BY CIMSS AT 15Z). THIS SHEARED PATTERN, WITHOUT ANY ACCURATE

MICROWAVE AND ASCAT DATA, PREVENT FROM LOCATING PRECISELY THE CENTER.

ACCORDING TO LAST INFRARED IMAGERY, THE SYSTEM MAY SLOWED DOWN

TEMPORARILY.



CARLOS KEEPS ON GOING GLOBALLY TO 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. FOR THE LONG RANGE, AS CARLOS SHOULD MAKE A U-TURN,

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

FOR A WEST-SOUTH-WESTWARD TRACK.



TOMORROW, THE SHARP INCREASE OF VWS THEN A BAROCLINIC INTERACTION

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

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

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

FROM THE ENVIRONMENTAL SHEAR, BEFORE ENDING ITS TRANSITION, CARLOS

MAY REGAIN ITS TROPICAL CHARACTERISTICS ON MONDAY. HOWEVER, THE WEAK

OCEANIC POTENTIAL UNDERNEATH, IS LIKELY TO PREVENT FROM ANY

SIGNIFICANT DEEPENING THEN.=