WTIO30 FMEE 300703



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 7/9/20172018

1.A SEVERE TROPICAL STORM  9  (FLAMBOYAN)



2.A POSITION 2018/04/30 AT 0600 UTC:

WITHIN 20 NM RADIUS OF POINT 14.8 S / 84.7 E

(FOURTEEN    DECIMAL EIGHT   DEGREES SOUTH AND EIGHTY FOUR    DECIMAL

SEVEN   DEGREES EAST)

MOVEMENT : SOUTH 5 KT



3.A DVORAK ANALYSIS: 4.0/4.0/S 0.5/24 H



4.A CENTRAL PRESSURE: 987 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT

RADIUS OF MAXIMUM WINDS (RMW) :33 KM



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

28 KT NE: 190 SE: 380 SW: 440 NW: 120

34 KT NE: 120 SE: 180 SW: 190 NW: 80

48 KT NE: 40 SE: 60 SW: 60 NW: 0





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 600 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2018/04/30 18 UTC: 16.0 S / 84.1 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

24H: 2018/05/01 06 UTC: 17.2 S / 83.6 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

36H: 2018/05/01 18 UTC: 18.6 S / 83.3 E, MAX WIND=045 KT,

POST-TROPICAL DEPRESSION

48H: 2018/05/02 06 UTC: 20.0 S / 83.7 E, MAX WIND=040 KT,

POST-TROPICAL DEPRESSION

60H: 2018/05/02 18 UTC: 21.5 S / 84.4 E, MAX WIND=030 KT,

POST-TROPICAL DEPRESSION

72H: 2018/05/03 06 UTC: 23.3 S / 85.7 E, MAX WIND=030 KT,

EXTRATROPICAL DEPRESSION



2.B LONGER-RANGE OUTLOOK :

96H: 2018/05/04 06 UTC: 27.5 S / 90.2 E, MAX WIND=030 KT,

EXTRATROPICAL DEPRESSION





2.C ADDITIONAL INFORMATION:

T=4.0- CI=4.0-



FLAMBOYAN SHOW SOME SIGNS OF INTENSIFICATION SINCE THE LAST FEW HOURS

WITH A RAGGED EYE FORMED JUST BEFORE 06 UTC. SUBJECTIVE DVORAK

ESTIMATES FROM PGTW, KNES AND FMEE ARE IN THE 55-60 KT RANGE

(10-MIN). THE ADT IS AT 60 KT (10-MIN). A SMAP PASS AT 0011Z SHOW 60

KT MAX WINDS WITH POSSIBLE RAIN CONTAMINATION. THE ASCAT PASS AT

0410Z SHOW 50 KT WINDS. THE INTENSITY IS FINALLY SET AT 55 KT.



THE SYSTEM HAS SLOW DOWN OVER THE LAST FEW HOURS AND HAS TRACK MORE

POLEWARDS. IT SHOULD MAINTAIN A GENERAL SOUTH-SOUTH-WESTWARDS TRACK

WITHIN THE NEXT 24 HOURS BEFORE A SOUTHWARDS TURN TOMORROW AND THEN

ACCELERATING SOUTHEASTWARD FROM WEDNESDAY AHEAD OF A MID/UPPER LEVEL

TOUGH BEFORE EVACUATE TOWARD THE MID-LATITUDE. THE RSMC TRACK

FORECAST IS BASED ON THE MORE RELIABLE MODEL CONSENSUS (IFS / GFS /

UK)



THE SYSTEM HAS STILL TODAY A SMALL OPPORTUNITY FOR INTENSIFICATION AS

THE SHEAR IS STILL LOW AND EXCELLENT POLEWARD DIVERGENCE AHEAD OF AN

UPPER LEVEL TROUGH. BUT, PROGRESSIVELY, NORTHWESTWARD VERTICAL

WINDSHEAR ASSOCIATED TO THE TROUGH IS FORECASTED TO NOTICEABLY

INCREASE LEADING TO A WEAKENING OF THE SYSTEM TONIGHT. FROM

WEDNESDAY, INTERACTING WITH THE SUBTROPICAL JETSTREAM AND EVOLVING

OVER COOLER SST, THE SYSTEM SHOULD START ITS EXTRAPOLISATION PHASE

AND GAIN QUICKLY FRONTAL CHARACTERISTICS.=