WTIO30 FMEE 290042



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 2/9/20172018

1.A MODERATE TROPICAL STORM  9  (FLAMBOYAN)



2.A POSITION 2018/04/29 AT 0000 UTC:

WITHIN 25 NM RADIUS OF POINT 11.2 S / 88.9 E

(ELEVEN    DECIMAL TWO   DEGREES SOUTH AND EIGHTY EIGHT    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : SOUTH-WEST 13 KT



3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/6 H



4.A CENTRAL PRESSURE: 1000 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT

RADIUS OF MAXIMUM WINDS (RMW) :37 KM



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

28 KT NE: 80 SE: 150 SW: 110 NW: 80

34 KT NE: 60 SE: 90 SW: 70 NW: 60







7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 900 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM



1.B FORECASTS:

12H: 2018/04/29 12 UTC: 12.4 S / 87.0 E, MAX WIND=045 KT, MODERATE

TROPICAL STORM

24H: 2018/04/30 00 UTC: 13.6 S / 85.5 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

36H: 2018/04/30 12 UTC: 14.7 S / 84.7 E, MAX WIND=055 KT, SEVERE

TROPICAL STORM

48H: 2018/05/01 00 UTC: 15.9 S / 84.3 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

60H: 2018/05/01 12 UTC: 17.3 S / 84.2 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

72H: 2018/05/02 00 UTC: 19.1 S / 84.8 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM



2.B LONGER-RANGE OUTLOOK :

96H: 2018/05/03 00 UTC: 22.1 S / 86.2 E, MAX WIND=030 KT, FILLING UP

120H: 2018/05/04 00 UTC: 26.8 S / 87.8 E, MAX WIND=025 KT, FILLING UP



2.C ADDITIONAL INFORMATION:

T=CI=3.0-



ON THE LAST SAT IMAGES, CONVECTION WRAPPED AGAIN TIGHTLY AROUND THE

CENTER, REACHING .7 AT 00Z. THE 1834Z AMSR2 AND 2231Z AMSU-B MW

IMAGES STILL SHOW A COMPACT AND ALREADY WELL DEFINED INNER CORE.

OBJECTIVE (ADT) AND SUBJECTIVE DVORAK ESTIMATES FROM OTHER AGENCIES

ARE IN AGREEMENT WITH THE RSMC ANALYSIS AT 3.0.



FLAMBOYAN SHOULD FOLLOW A CLASSIC PARABOLIC TRACK STEERED BY A

MID-TROPOSPHERE RIDGE CURRENTLY LOCATED IN THE SOUTH-EAST. THE

DISPERSION OF THE AVAILABLE DETERMINISTIC AND ENSEMBLE MODELS

INCREASES FROM TUESDAY, AS THE ARRIVAL OF A MID-LATITUDES TROUGH IN

THE SOUTH-WEST COULD ACCELERATE (OR NOT) THE EVACUATION OF THE SYSTEM

TOWARDS THE SOUTH-EAST. THE RSMC TRACK FORECAST IS BASED ON A MODEL

CONSENSUS.



FLAMBOYAN IS CURRENTLY LOCATED UNDER THE AXIS OF THE NEAR EQUATORIAL

UPPER RIDGE, THE EASTERLY WINDSHEAR THUS REMAINS  LOW AND THE UPPER

DIVERGENCE IS STRONG. THE SYSTEM SHOULD BENEFIT FROM THIS CONDUCIVE

ENVIRONMENTAL CONDITIONS TO GRADUALLY INTENSIFY TODAY AND TOMORROW

MORNING. FROM MONDAY AFTERNOON, DRY AIR COULD BEGIN TO SLITHER IN THE

CIRCULATION THANKS TO AN EASTERLY SHEAR CONSTRAINT APPEARING IN THE

MID-LEVELS. FROM TUESDAY, THE STRENGTHENING OF AN UPPER

NORTH-WESTERLY SHEAR AND THE DECREASE OF THE ENERGY IN THE OCEAN

SOUTH OF 20S WILL TRIGGER THE WEAKENING PHASE OF FLAMBOYAN. THE

SYSTEM IS EXPECTED TO FILL-UP BY THE END OF THE TAUS WHILE TRACKING

SOUTHWARD.=