WTIO30 FMEE 041216



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 34/5/20172018

1.A SEVERE TROPICAL STORM  5  (CEBILE)



2.A POSITION 2018/02/04 AT 1200 UTC:

WITHIN 20 NM RADIUS OF POINT 20.8 S / 80.2 E

(TWENTY    DECIMAL EIGHT   DEGREES SOUTH AND EIGHTY    DECIMAL TWO

DEGREES EAST)

MOVEMENT : SOUTH-EAST 8 KT



3.A DVORAK ANALYSIS: 2.5/3.5/W 1.0/12 H



4.A CENTRAL PRESSURE: 978 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT

RADIUS OF MAXIMUM WINDS (RMW) :83 KM



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

28 KT NE: 240 SE: 460 SW: 410 NW: 190

34 KT NE: 220 SE: 330 SW: 300 NW: 170

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





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 900 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/02/05 00 UTC: 22.3 S / 80.9 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

24H: 2018/02/05 12 UTC: 24.0 S / 81.3 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

36H: 2018/02/06 00 UTC: 25.4 S / 81.2 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

48H: 2018/02/06 12 UTC: 26.6 S / 80.9 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

60H: 2018/02/07 00 UTC: 27.4 S / 80.4 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

72H: 2018/02/07 12 UTC: 27.7 S / 80.0 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2018/02/08 12 UTC: 26.8 S / 76.7 E, MAX WIND=040 KT, FILLING UP

120H: 2018/02/09 12 UTC: 29.0 S / 72.7 E, MAX WIND=030 KT, FILLING UP



2.C ADDITIONAL INFORMATION:

T=2.5 CI=3.5



DURING THE LAST 6 HOURS, THE CENTER HAS APPEARED FULLY EXPOSED DUE TO

THE STRONG NORTHWESTWARD VERTICAL WINDSHEAR. DEEP CONVECTION REMAINS

LOCATED OVER THE SOUTHEASTERN QUADRANT BUT WITH WARMER AND WARMER TOP

CLOUDS.



CEBILE KEEPS ON ITS SOUTHEASTWARD TRACK STEERING BY THE MID LEVEL

RIDGE LOCATED ON NORTHEASTERN OF THE SYSTEM. FROM TOMORROW, THE

SYSTEM SHOULD CURVE SOUTHWARD DUE TO THE STRENGTHENING OF THIS RIDGE.

FROM WEDNESDAY AS THE LOW/MID LEVEL PATTERN BECOMES MORE MERIDIAN, A

RIDGE IS EXPECTED TO DEVELOP SOUTH OF THE SYSTEM. AS A CONSEQUENCE,

THE SYSTEM SHOULD SLOW DOWN AND RE-ORIENT ITS TRACK WESTWARD FROM

THURSDAY.



ATMOSPHERIC AND OCEANIC CONTEXT IS NOW UNFAVORABLE. OCEANIC HEAT

CONTENT IS WEAK. UPPER LEVEL FLOW IS RAPID AHEAD A TROUGH AND

GENERATES A STRONG NORTHWESTWARD VERTICAL WINDSHEAR. ONLY A STRONG

CONFLUENCE IN ENTRANCE REGION OF THE UPPER LEVEL JET LOCATED SOUTH OF

THE SYSTEM SUPPLIES A GOOD UPPER LEVEL DIVERGENCE THAT SUSTAINS DEEP

CONVECTION WITHIN THE SOUTHERN QUADRANT OF THE SYSTEM. SO, CEBILE IS

FORECASTED TO WEAKEN BUT IT SHOULD CONSERVE A WARM CORE BECOMING LESS

AND LESS DEEP. TUESDAY EVENING, THE UPPER LEVEL TROUGH SHOULD SHIFT

ABOVE THE CIRCULATION. THE DECREASING VERTICAL WINDSHEAR COULD ALLOW

THE CONVECTION TO DEVELOP NEAR THE CENTER. BUT, WEDNESDAY EVENING, AN

INCREASING SOUTHERN VERTICAL WINDSHEAR BEHING THE UPPER LEVEL TROUGH

AND THE ARRIVAL OF AN UPPER LEVEL DYNAMICAL RIDGE SHOULD INITIATE THE

FILLING OF CEBILE.=