WTIO30 FMEE 021218



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 26/5/20172018

1.A TROPICAL CYCLONE  5  (CEBILE)



2.A POSITION 2018/02/02 AT 1200 UTC:

WITHIN 20 NM RADIUS OF POINT 17.6 S / 75.8 E

(SEVENTEEN    DECIMAL SIX   DEGREES SOUTH AND SEVENTY FIVE    DECIMAL

EIGHT   DEGREES EAST)

MOVEMENT : SOUTH 5 KT



3.A DVORAK ANALYSIS: 4.5/5.0/W 1.0/12 H



4.A CENTRAL PRESSURE: 960 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 80 KT

RADIUS OF MAXIMUM WINDS (RMW) :65 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: 70 SE: 70 SW: 70 NW: 70



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1000 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/02/03 00 UTC: 18.2 S / 76.3 E, MAX WIND=070 KT, TROPICAL

CYCLONE

24H: 2018/02/03 12 UTC: 18.8 S / 77.5 E, MAX WIND=065 KT, TROPICAL

CYCLONE

36H: 2018/02/04 00 UTC: 19.6 S / 78.8 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM

48H: 2018/02/04 12 UTC: 20.7 S / 79.8 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

60H: 2018/02/05 00 UTC: 21.8 S / 80.6 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

72H: 2018/02/05 12 UTC: 23.0 S / 81.2 E, MAX WIND=055 KT,

POST-TROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2018/02/06 12 UTC: 25.4 S / 81.3 E, MAX WIND=050 KT,

POST-TROPICAL DEPRESSION

120H: 2018/02/07 12 UTC: 27.2 S / 80.4 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION



2.C ADDITIONAL INFORMATION:

T=4.5+ CI=5.0+



DURING THE LAST 6 HOURS, CEBILE IS GOING ON WEAKENING PHASE WITH A

EYE BECOMING LARGER AND ALONGATED.

THIS CHANGE MAY BE THE CONSEQUENCE OF THE ARRIVAL OVER WATERS WITH

LESS ENERGETICAL POTENTIAL ACCORDING TO MERCATOR DATA AND ALSO THE

WRAPPINF DRY AIR IN THE NORTHERN SEMI-CERCLE. 1057Z AMSU SWATH

CONFIRM THIS WEAKENING WITH A OPEN  EYEWALL IN THE NORTH QUADRANT.



CEBILE KEEPS ON TRACKING SOUTHWARD TO SOUTH-SOUTHEASTWARD, AFTER THE

WEAKENING OF THE SUBTROPICAL RIDGE. BY NEXT NIGHT, UNDER THE

INFLUENCE OF THE NEAR-EQUATORIAL RIDGE, THE SYSTEM WILL PROGRESSIVELY

TURN SOUTHEASTWARD WHILE ACCELERATING A LITTLE. AT LONG RANGE, THE

ARRIVAL OF A TROUGH AT SOUTH IS LIKELY TO ATTRACT CEBILE AND THUS

INDUCE A MORE SOUTHWARD TRACK.



THE ATMOSPHERIC AND OCEANIC CONTEXT  START DETERIORATING. A WEAK

WEST-NORTHWESTERLY UPPER CONSTRAINT IS SETTING UP PROGRESSIVELY TODAY

AND THEN INCREASE SIGNIFICANTLY ON SATURDAY WITH A ROSSBY WAVE

BREAKING, WEST OF THE SYSTEM. CEBILE'S INTENSITY IS FORECAST TO

DECAY, ALL THE MORE IT WILL EVOLVE OVER COOLER SST. ON MONDAY, WITH

AN UPPER ANOMALY IN THE VICINITY, THE BELOW 26 DEGREES SST AND THE

VENTING OF THE UPPER WARM CORE BY DRY ENVIRONMENTAL AIR , CEBILE IS

EXPECTED TO BEGIN ITS EXTRA-TROPICALISATION.=