WTIO30 FMEE 291229



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 10/5/20172018

1.A INTENSE TROPICAL CYCLONE  5  (CEBILE)



2.A POSITION 2018/01/29 AT 1200 UTC:

WITHIN 20 NM RADIUS OF POINT 15.7 S / 81.2 E

(FIFTEEN    DECIMAL SEVEN   DEGREES SOUTH AND EIGHTY ONE    DECIMAL

TWO   DEGREES EAST)

MOVEMENT : SOUTH-WEST 5 KT



3.A DVORAK ANALYSIS: 5.0/5.5/W 1.0/18 H



4.A CENTRAL PRESSURE: 946 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 95 KT

RADIUS OF MAXIMUM WINDS (RMW) :15 KM



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

28 KT NE: 240 SE: 330 SW: 280 NW: 170

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

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

64 KT NE: 40 SE: 40 SW: 40 NW: 40



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 00 UTC: 16.0 S / 80.3 E, MAX WIND=090 KT, TROPICAL

CYCLONE

24H: 2018/01/30 12 UTC: 16.2 S / 79.2 E, MAX WIND=085 KT, TROPICAL

CYCLONE

36H: 2018/01/31 00 UTC: 16.1 S / 78.3 E, MAX WIND=080 KT, TROPICAL

CYCLONE

48H: 2018/01/31 12 UTC: 16.0 S / 77.6 E, MAX WIND=080 KT, TROPICAL

CYCLONE

60H: 2018/02/01 00 UTC: 16.2 S / 76.8 E, MAX WIND=080 KT, TROPICAL

CYCLONE

72H: 2018/02/01 12 UTC: 16.4 S / 76.3 E, MAX WIND=080 KT, TROPICAL

CYCLONE



2.B LONGER-RANGE OUTLOOK :

96H: 2018/02/02 12 UTC: 17.1 S / 75.9 E, MAX WIND=075 KT, TROPICAL

CYCLONE

120H: 2018/02/03 12 UTC: 18.5 S / 77.1 E, MAX WIND=060 KT, SEVERE

TROPICAL STORM



2.C ADDITIONAL INFORMATION:

T=5.0+ CI=5.5+



DURING THE LAST 6 HOURS, EYE HAS WARMED SUGGESTING A NEW PHASE OF

INTENSIFICATION BUT HAS BECOME LESS DEFINED SINCE 1030Z. MICROWAVE

PATTERN HAS NOT MUCH EVOLVED (GCOM 0710Z) WITH A PINHOLE EYE AND AN

OUTER INTENSE CONVECTION BAND THAT WRAPS AROUND THE CENTRE SUGGESTING

THAT AN ERC COULD OCCUR.



CEBILE TRACKS SOUTH-WESTWARD ON THE NORTH-WESTERN EDGE OF THE

SUBTROPICAL RIDGE. THEN THE REINFORCEMENT AND THE NORTHWARD EXTENSION

OF THE RIDGE IN ITS SOUTH-WESTERN PART WILL SLOW THE MOVEMENT OF

CEBILE AND BEND THE FORWARD MOTION TEMPORARILY TOWARDS THE WEST. IN

THE MIDDLE OF NEXT WEEK, THE RIDGE WEAKENS TO ITS SOUTH-EAST ALONG

WITH A BUILDING NEAR EQUATORIAL RIDGE TO ITS NORTH-EAST ALLOWING THE

SYSTEM TO TAKE A TURN SOUTHEASTWARD. HOWEVER THERE IS ALWAYS A LARGE

UNCERTAINTY ABOUT THE TRACK BEYOND MONDAY MAINLY DU TO THE WIDE

VARIABILITY IN THE SPEED OF MOVEMENT AMONG THE NUMERICAL GUIDANCE. SO

THERE IS STILL SOME SIGNIFICANT UNCERTAINTY ON WHERE THE SYSTEM IS

EXPECTED TO TURN SOUTH-EASTWARD. THE CURRENT FORECAST IS A BLEND OF

THE LATEST GUIDANCE.



ALONG THIS TRACK, THE UPPER LEVEL CONSTRAINT IS WEAK, AND THE UPPER

DIVERGENCE VERY GOOD. SO THE SYSTEM IS FORECASTED TO KEEP A

SIGNIFICANTLY INTENSITY. THE LIMITING PARAMETERS SHOULD BE A REDUCED

OHC TODAY AND TOMORROW AND THEN A MID-LEVEL DRY ENVIRONMENT

SPECIALLY OVER THE WESTERN AND NORTHERN SEMI-CIRCLE. A CLEAR

WEAKENING IS EXPECTED AT THE END OF THE FORECAST PERIOD AS A WESTERLY

VERTICAL SHEAR SHOULD INCREASE.=