WTIO30 FMEE 050621



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 8/4/20162017

1.A SEVERE TROPICAL STORM  4  (CARLOS)



2.A POSITION 2017/02/05 AT 0600 UTC:

WITHIN 20 NM RADIUS OF POINT 17.3 S / 56.9 E

(SEVENTEEN    DECIMAL THREE   DEGREES SOUTH AND FIFTY SIX    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : SOUTH-EAST 2 KT



3.A DVORAK ANALYSIS: 3.5/3.5/S 0.0/0 H



4.A CENTRAL PRESSURE: 987 HPA

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

RADIUS OF MAXIMUM WINDS (RMW) :15 KM



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

28 KT NE: 60 SE: 70 SW: 60 NW: 50

34 KT NE: 50 SE: 60 SW: 50 NW: 40

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





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2017/02/05 18 UTC: 17.6 S / 57.2 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

24H: 2017/02/06 06 UTC: 18.2 S / 57.1 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

36H: 2017/02/06 18 UTC: 19.5 S / 56.4 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

48H: 2017/02/07 06 UTC: 20.5 S / 55.2 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

60H: 2017/02/07 18 UTC: 21.4 S / 53.4 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

72H: 2017/02/08 06 UTC: 22.0 S / 51.8 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2017/02/09 06 UTC: 22.9 S / 51.1 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

120H: 2017/02/10 06 UTC: 24.5 S / 51.5 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=CI=3.5



OVER THE PAST SIX HOURS, CLOUD PATTERN HAS NOT EVOLVED A LOT. CARLOS

REMAINS A SMALL SYSTEM WITH A CENTER BENEATH A COMPACT CDO. 0231Z 85

GHZ SSMIS MICRO-WAVE IMAGERY SHOWED AN EYE FEATURE AND JUSTIFIED THE

STAGE OF SEVERE TROPICAL STORM. HOWEVER THIS CURRENTLY ASSESSMENT IS

A BIT HIGHTER THAN OBJECTIVE DVORAK ESTIMATION LIKE ADT FROM CIMSS.



CURRENTLY CARLOS IS MOVING SOUTHEASTWARD DUE TO THE GROWING INFLUENCE

OF THE UPPER LEVEL TROUGH SOUTH OF THE MASCARENE ISLANDS. THIS NIGHT,

THE SYSTEM SHOULD TURN TOWARD THE SOUTH BEFORE GRADUALLY ACCCELERATE

SOUTHWESTWARD TOMOROW. FROM THURSDAY, CARLOS IS FORECASTED DO SLOW

DOWN AND TURN SOUTHEASTWARD.THE AVAILABLE GUIDANCE IS IN RATHER GOOD

AGREEMENT ON THIS TRACK FORECAST. THE FORECAST TRACK IS A CONSENSUS

OF LAST AVAILABLE NUMERICAL MODELS.



CARLOS INTENSITY FORECAST REMAINS CHALLENGING BECAUSE OF ITS SMALL

SIZE, MAKING IT MORE SENSITIVE TO ITS ENVIRONMENT. TODAY,

ENVIRONMENTAL CONDITIONS REMAINS GOOD. THE VERTICAL WINDSHEAR IS WEAK

WITH A GOOD OUTFLOW CHANNEL DUE TO THE AFOREMENTIONNED UPPER LEVEL

TROUGH. HOWEVER, EQUATORIAL UPPER LEVEL DIVERGENCE IS LESS GOOD. FROM

TOMOROW, THE NORTHWESTERN VERTICAL WINDSHEAR IS FORESCATED TO

INCREASE AS THE SYSTEM WILL MOVE CLOSE OVER THE MASCARENES ISLAND

INDUCING A WEAKENING PHASE OF CARLOS. FROM WEDNESDAY, ENVIRONNEMENTAL

CONDITIONS SHOULD BECOME MORE FAVORABLE WITHIN AN IMPROVING

ENVIRONMENT.=