WTIO30 FMEE 230015



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 48/8/20152016

1.A SEVERE TROPICAL STORM  8  (FANTALA)



2.A POSITION 2016/04/23 AT 0000 UTC:

WITHIN 30 NM RADIUS OF POINT 12.7 S / 56.9 E

(TWELVE    DECIMAL SEVEN   DEGREES SOUTH AND FIFTY SIX    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : WEST-NORTH-WEST 4 KT



3.A DVORAK ANALYSIS: 4.0/4.0/D 1.5/24 H



4.A CENTRAL PRESSURE: 984 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 60 KT

RADIUS OF MAXIMUM WINDS (RMW) :9 KM



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

28 KT NE: 90 SE: 150 SW: 150 NW: 90

34 KT NE: 40 SE: 70 SW: 70 NW: 40

48 KT NE: 20 SE: 30 SW: 30 NW: 20





7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 400 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2016/04/23 12 UTC: 12.4 S / 55.3 E, MAX WIND=050 KT, SEVERE

TROPICAL STORM

24H: 2016/04/24 00 UTC: 11.7 S / 53.8 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

36H: 2016/04/24 12 UTC: 10.8 S / 52.4 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

48H: 2016/04/25 00 UTC: 9.4 S / 50.6 E, MAX WIND=030 KT, TROPICAL

DEPRESSION

60H: 2016/04/25 12 UTC: 8.6 S / 48.7 E, MAX WIND=025 KT, LOW

72H: 2016/04/26 00 UTC: 8.0 S / 46.7 E, MAX WIND=025 KT, LOW



2.B LONGER-RANGE OUTLOOK :

96H: 2016/04/27 00 UTC: 6.8 S / 43.3 E, MAX WIND=020 KT, DISSIPATING

120H: 2016/04/28 00 UTC: 4.4 S / 39.7 E, MAX WIND=020 KT, DISSIPATING



2.C ADDITIONAL INFORMATION:

T=4.0, CI=4.0+



DURING THE LAST 6 HOURS, FANTALA'S CLOUD PATTERN HAS NOT EVOLVED SO

MUCH WITH A SMALL CDO ABOUT 100 NM OF DIAMETER. VAPOR WATER IMAGERY

SHOWS A VERY DRY MID-LEVEL ENVIRONMENT OVER THE SOUTHERN AND WESTERN

SIDE OF THE SYSTEM THAT HAS REDUCED THE DEEP CONVECTION FOR 24H.



THE BUILDING OF A HIGH GEOPOTENTIAL CELL IS EXPECTED TO STRENGTHEN A

LOW/MID LEVEL SUBTROPICAL RIDGE OVER THE BASIN. THIS PATTERN SHOULD

GENERATE PROGRESSIVELY A SOUTHEASTWARD STEERING FLOW. SO, FANTALA IS

FORECASTED TO PROGRESSIVELY ACCELERATE TOWARD THE NORTHWEST.



ON THIS TRACK, FANTALA SHOULD EVOLVE NORTH OF THE UPPER LEVEL WESTERN

WIND BELT WHICH IS EXPECTED TO MOVE NORTHWARD IN THE NEXT FEW DAYS.

SO, VERTICAL WIND SHEAR SHOUD REMAINS WEAK. HOWEVER, FANTALA IS

EXPECTED TO FOLLOW A TRACK THAT IT HAD ALREADY FOLLOWED TWICE...! THE

OCEAN HEAT CONTENT SHOULD BEGIN TO BECOME VERY WEAK ! LAST,

ASSOCIATED TO THE LOW/MID LEVEL SUBTROPICAL RIDGE, THE SOUTHEASTWARD

STEERING FLOW SHOULD CONTINUETO DRY FANTALA'S ENVIRONMENT. SO, WITH

THESE UNFAVOURABLE ENVIRONMENTAL CONDITIONS (ESPECIALLY FOR A MIDGET

SYSTEM), FANTALA IS LIKELY TO WEAKEN VERY RAPIDLY DURING THE NEXT

DAYS.=