WTIO30 FMEE 221237



RSMC / TROPICAL CYCLONE CENTER / LA REUNION

TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)



0.A WARNING NUMBER: 12/1/20152016

1.A MODERATE TROPICAL STORM  1  (ANNABELLE)



2.A POSITION 2015/11/22 AT 1200 UTC:

WITHIN 20 NM RADIUS OF POINT 12.6 S / 71.9 E

(TWELVE    DECIMAL SIX   DEGREES SOUTH AND SEVENTY ONE    DECIMAL

NINE   DEGREES EAST)

MOVEMENT : SOUTH-SOUTH-EAST 5 KT



3.A DVORAK ANALYSIS: 3.0/3.5/S 0.0/24 H



4.A CENTRAL PRESSURE: 994 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 45 KT

RADIUS OF MAXIMUM WINDS (RMW) :56 KM



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

28 KT NE: 90 SE: 190 SW: 190 NW: 90

34 KT NE: 70 SE: 110 SW: 110 NW: 70







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

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP



1.B FORECASTS:

12H: 2015/11/23 00 UTC: 14.1 S / 73.0 E, MAX WIND=040 KT, MODERATE

TROPICAL STORM

24H: 2015/11/23 12 UTC: 15.8 S / 74.7 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

36H: 2015/11/24 00 UTC: 18.0 S / 77.4 E, MAX WIND=035 KT, MODERATE

TROPICAL STORM

48H: 2015/11/24 12 UTC: 21.2 S / 79.2 E, MAX WIND=030 KT, TROPICAL

DEPRESSION

60H: 2015/11/25 00 UTC: 22.7 S / 79.7 E, MAX WIND=025 KT, LOW

72H: 2015/11/25 12 UTC: 23.8 S / 79.5 E, MAX WIND=025 KT, LOW



2.B LONGER-RANGE OUTLOOK :

96H: 2015/11/26 12 UTC: 23.1 S / 77.4 E, MAX WIND=020 KT, REMNANT LOW





2.C ADDITIONAL INFORMATION:

FT=3.0- AND CI=3.5-



ANNABELLE SHOWS A WEAKENING TREND, WITH A RECENT SHEARED PATTERN

CONFIGURATION AND THE LOW LEVEL CIRCULATION APPEARING NORTH OF THE

DEEP CONVECTION.

THE CENTRAL DEEP CONVECTION TENDS TO DISORGANIZE DURING THE PAST SIX

HOURS.



THE LLCC IS MOVING FASTER SOUTH-SOUTH-EASTWARD.



THE AVAILABLE NWP MODELS ARE IN TIGHT AGREEMENT FOR AN ACCELERATING

SOUTH-SOUTH-EASTWARD MOVEMENT, BECOMING SOUTH-EAST FROM THE NEXT

NIGHT, TOWARDS A WIDE MID-TROPOSPHERIC TROUGH.

ON THIS PATH, ANNABELLE IS FORECAST TO ENCOUNTER TOMORROW LOW HEAT

POTENTIAL SEAS, SOUTH OF 15S.

THE NORTH-WESTERLY UPPER WINDS WILL STRENGTHEN ABOVE THE SYSTEM,

AHEAD OF AN UPPER LEVELS TROUGH.

DURING THE NEXT NIGHT AND TOMORROW, THE IMPACT OF THE UPPER WINDS

SHOULD BE OFFSET BY THE FAST MOVEMENT SOUTH-EASTWARD OF THE LLCC.

ON TUESDAY, THE LLCC IS LIKELY TO INTERACT WITH THE UPPER TROUGH AND

SUBTROPICAL JET AND ALLOW A TEMPORARY DEEPENING.

FROM WEDNESDAY, AS THE UPPER TROUGH SHOULD SHIFT EASTWARDS, THE

WESTERLY VERTICAL WINDSHEAR WILL BECOME VERY UNFAVORABLE, AND THE

LLCC IS LIKELY TO FILL UP RAPIDLY. THE TRACK OF THE RESIDUAL LOW

SHOULD THEN BEND EASTWARD, BETWEEN 20S AND 25S, STEERED BY THE

SUBTROPICAL RIDGE.=