WTIO30 FMEE 291858



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 11/5/20172018

1.A TROPICAL CYCLONE  5  (CEBILE)



2.A POSITION 2018/01/29 AT 1800 UTC:

WITHIN 20 NM RADIUS OF POINT 15.7 S / 80.7 E

(FIFTEEN    DECIMAL SEVEN   DEGREES SOUTH AND EIGHTY    DECIMAL SEVEN

DEGREES EAST)

MOVEMENT : WEST-SOUTH-WEST 5 KT



3.A DVORAK ANALYSIS: 4.5/5.5/W 1.5/24 H



4.A CENTRAL PRESSURE: 955 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 85 KT

RADIUS OF MAXIMUM WINDS (RMW) :11 KM



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

28 KT NE: 190 SE: 330 SW: 330 NW: 150

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

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

64 KT NE: 30 SE: 30 SW: 30 NW: 30



7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1100 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/01/30 06 UTC: 16.0 S / 79.7 E, MAX WIND=085 KT, TROPICAL

CYCLONE

24H: 2018/01/30 18 UTC: 16.0 S / 78.8 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

36H: 2018/01/31 06 UTC: 15.9 S / 78.0 E, MAX WIND=105 KT, INTENSE

TROPICAL CYCLONE

48H: 2018/01/31 18 UTC: 16.0 S / 77.3 E, MAX WIND=095 KT, INTENSE

TROPICAL CYCLONE

60H: 2018/02/01 06 UTC: 16.3 S / 76.7 E, MAX WIND=085 KT, TROPICAL

CYCLONE

72H: 2018/02/01 18 UTC: 16.7 S / 76.4 E, MAX WIND=085 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2018/02/02 18 UTC: 18.0 S / 76.9 E, MAX WIND=080 KT, TROPICAL

CYCLONE

120H: 2018/02/03 18 UTC: 19.9 S / 79.3 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=4.5+ CI=5.5



MICROWAVE IMAGERY OF THIS EVENING CLEARLY SHOW THAT CEBILE IS

UNDERGOING EN EYEWALL REPLACEMENT CYCLE (ERC). AN OUTER RING OF

CONVECTION IS NOW ENCOMPASSING THE TINY INNER CORE THAT SHOW SOME

SIGNS OF WEAKENING. THE SYSTEM IS NOW ON A WEAKENING TREND AND THE

INTENSITY ASSESSMENT HAS BEEN PUT JUST BELOW ALL DVORAK ESTIMATES.



CEBILE TRACKS HAS STARTED TO SLOW DOWN AND BEND WESTWARDS DUE TO THE

REINFORCEMENT AND THE NORTHWARD EXTENSION OF THE RIDGE IN ITS

SOUTH-WESTERN PART. IN THE MIDDLE OF THE WEEK, THE SUBTROPICAL RIDGE

WEAKENS TO ITS SOUTH-EAST ALONG WITH A BUILDING NEAR EQUATORIAL RIDGE

TO ITS NORTH-EAST ALLOWING THE SYSTEM TO TAKE A SOUTHEASTWARD TURN.

MODELS ARE GRADUALLY BECOMING IN BETTER AGREEMENT ON THE LOCALIZATION

OF THE TURN (UKMO REMAINS AN OUTLIER TO THE EAST) BUT SIGNIFICANT

DIFFERENCES IN THE FORWARD MOTION ARE STILL NOTED AMONG THE NUMERICAL

GUIDANCE. LATEST AVAILABLE NWP (INCLUDING SOME OF THE 12Z CYCLE) SHOW

A FASTER TRACK FROM WEDNESDAY AND BEYOND AND SO THE OFFICIAL

FORECAST.



THE CURRENT WEAKENING TREND DUE TO THE ERC IS LIKELY TEMPORARILY. AS

THE SYSTEM WILL TRACK WESTWARDS, IT WILL MOVE THROUGH A NEAR PERFECT

ENVIRONMENT IN TERM OF SHEAR, UPPER LEVEL DIVERGENCE AND OCEANIC

CONTAIN (IT IS EXPECTED TO INCREASE UNDER THE SYSTEM AS LONG AS IT

MOVE WEST OF 80E AND STAY NORTH OF 18S). IT SHOULD ALLOW THE

INNER-CORE TO BE PROTECTED FROM THE DRY MID-LEVEL AIR ALTHOUGH THE

SLOW FORWARD MOTION. THE MOTION IS HYPOTHESIZED TO BE "FAST" ENOUGH

TO PREVENT SELF-INDUCED OCEANIC COOLING. A SECOND PEAK OF INTENSITY

APPEAR NOW LIKELY PENDING ON WHEN THE ERC WILL END. SOME UNCERTAINTY

REMAINS ON THAT POINT AND THE CURRENT FORECAST SUPPOSED THAT

INTENSIFICATION MAY RESUME TOMORROW.



A CLEAR WEAKENING TREND IS STILL EXPECTED AT THE END OF THE FORECAST

PERIOD AS A WESTERLY VERTICAL SHEAR SHOULD INCREASE.=