WTIO30 FMEE 030024



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 28/5/20172018

1.A TROPICAL CYCLONE  5  (CEBILE)



2.A POSITION 2018/02/03 AT 0000 UTC:

WITHIN 21 NM RADIUS OF POINT 18.2 S / 76.4 E

(EIGHTEEN    DECIMAL TWO   DEGREES SOUTH AND SEVENTY SIX    DECIMAL

FOUR   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-EAST 5 KT



3.A DVORAK ANALYSIS: 4.5/4.5/W 0.5/12 H



4.A CENTRAL PRESSURE: 958 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 75 KT

RADIUS OF MAXIMUM WINDS (RMW) :74 KM



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

28 KT NE: 240 SE: 500 SW: 430 NW: 280

34 KT NE: 170 SE: 240 SW: 240 NW: 190

48 KT NE: 110 SE: 150 SW: 150 NW: 130

64 KT NE: 80 SE: 80 SW: 80 NW: 80



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 700 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/02/03 12 UTC: 18.7 S / 77.4 E, MAX WIND=065 KT, TROPICAL

CYCLONE

24H: 2018/02/04 00 UTC: 19.5 S / 78.8 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

36H: 2018/02/04 12 UTC: 20.6 S / 79.7 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

48H: 2018/02/05 00 UTC: 21.8 S / 80.4 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

60H: 2018/02/05 12 UTC: 23.1 S / 80.9 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

72H: 2018/02/06 00 UTC: 24.2 S / 81.0 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2018/02/07 00 UTC: 26.5 S / 80.5 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

120H: 2018/02/08 00 UTC: 28.6 S / 80.5 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=CI=4.5



DURING THE LAST 6 HOURS, THE EYE PATTERN OF CEBILE WAS VERY

FLUCTUATING. UNDER THE EFFECT OF A WEST-NORTHWESTERLY UPPER

CONSTRAINT, CONVECTION IN THE WESTERN AREA HAS QUASIALLY DISAPPEARED

IN INFRARED DATA. THIS IS ALSO REMARKABLE ON 2331 UTC MICROWAVE

IMAGES. THIS UPPER CONSTRAINT CONTRIBUTES TO WEAKENING INTENSITY AND

CEBILE IS NOW IN A LOWER-TERM PHASE OF WEAKENING.



THE CURRENT STRENGTHENING OF THE NEAR-EQUATORIAL RIDGE TAKE NOW THE

CYCLONE TRACK TOWARDS THE SOUTHEASTWARD. THE DISPLACEMENT WILL

SLIGHTLY ACCELERATE TODAY.  FROM MONDAY, THE ARRIVAL OF A TROUGH AT

SOUTH ALLOWS TO MOVE EAST HIGH PRESSURES AND THUS ORIENTED THE

CEBILE'S TRACK FURTHER SOUTHWARD BUT WITHOUT REAL ACCELERATION. THE

RECONSTRUCTION OF THE SOUTHERN RIDGE COULD, HOWEVER, DISTURB THIS

PROGRESSION SOUTHWARD FROM THURSDAY AS SUGGESTED THE ENSEMBLIST

FORECAST OF THE IFS NUMERICAL MODEL.



THE ATMOSPHERIC AND OCEANIC CONTEXT IS NOT FAVORABLE TO MAINTAIN THE

INTENSITY FOR THE CEBILE CYCLONE. ROSSBY WAVE BREAKING TO THE WEST OF

THE SYSTEM ALLOWS A WEST-NORTHWESTERLY UPPER CONSTRAINT. CEBILE'S

INTENSITY IS FORECAST TO DECAY, ALL THE MORE IT WILL EVOLVE OVER

COOLER SST, AND WILL CONTINUE THIS WEAKENING BEFORE STARTING ITS

POST-TROPICAL TRANSITION FROM TUESDAY WITH THE STRONGEST WINDS IN THE

SOUTHERN QUADRANT, FAR FROM THE CENTER.=