Direction Interrégionale de LA REUNION
B.P.4    97491 Ste Clotilde Cedex
Téléphone                02.62.92.11.00
Fax exploitation      02.62.92.11.48
Fax direction           02.62.92.11.47


WTIO30 FMEE 110634


RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE TECHNICAL BULLETIN (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 28/8/20092010
1.A SEVERE TROPICAL STORM 8 (EDZANI)

2.A POSITION 2010/01/11 AT 0600 UTC :
WITHIN 20 NM RADIUS OF POINT 25.0S / 71.8E
(TWENTY FIVE DECIMAL ZERO DEGREES SOUTH AND SEVENTY ONE DECIMAL EIGHT
DEGREES EAST)
MOVEMENT : SOUTH-SOUTH-EAST 8 KT

3.A DVORAK ANALYSIS : 3.0/3.5 /W 2.0/24 H
4.A CENTRAL PRESSURE : 985 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT
RADIUS OF MAXIMUM WINDS (RMW) : 30 KM

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 300 SE: 300 SO: 240 NO: 240
50 KT NE: 030 SE: 030 SO: 030 NO: 030

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 1200 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2010/01/11 18 UTC: 25.8S/72.3E, MAX WIND=050KT, SEVERE TROP. STORM.
24H: 2010/01/12 06 UTC: 26.3S/71.6E, MAX WIND=050KT, SEVERE TROP. STORM.
36H: 2010/01/12 18 UTC: 27.1S/69.7E, MAX WIND=045KT, MODERATE TROP. STORM
.
48H: 2010/01/13 06 UTC: 28.4S/67.9E, MAX WIND=040KT, MODERATE TROP. STORM
.
60H: 2010/01/13 18 UTC: 30.2S/67.8E, MAX WIND=040KT, BECOMING
EXTRATROPICAL.
72H: 2010/01/14 06 UTC: 32.5S/69.3E, MAX WIND=040KT, EXTRATROPICAL.

2.B OTHER INFORMATIONS:
T=3.0 AND CI=3.5

ANIMATED IMAGERY SHOWS THE TRACK IS SOUTH-SOUTHEASTWARDS OVER THE VERY
LAST HOURS. WEAKENING IS STILL ON ITS WAY, AND LATEST AVAILABLE SATELLITE
IMAGERY SHOWS A SHEAR PATTERN WITH A CENTRE EXPOSED AT LESS THAN 30MN IN
THE WEST OF THE DEEP CONVECTION.

EDZANI IS NOW OVER COOLER WATERS (26.5c).
LATEST AVAILABLE NWP OUTPUTS SUGGEST A DEACREASING WESTERLY SHEAR AFTER
RANGE 12 AND UNTIL WEDNESDAY 06TU. CONSEQUENTLY WEAKENING SHOULD BE
RATHER SLOW OVER THAT PERIOD.

THE SYSTEM IS UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE (STR)
LOCATED IN THE EAST, WHICH IS RESPONSIBLE FOR THE SOUTHEASTWARDS TRACK
FORECASTED FOR THE NEXT 12H. BEYOND, A NEW BUILDING STR HAMPERS THE
SYSTEM TO KEEP ON TRACKING SOUTHWARDS; EDZANI SHOULD THEREFORE SLOW DOWN
AND THE TRACK
SHOULD TAKE A TEMPORAL WEST-SOUTHWESTWARDS COMPONENT AND THEN RECURVE
AGAIN SOUTHWARDS.

EXTRATROPICAL TRANSITION IS EXPECTED AFTER RANGE 48. BEYOND 60H, SYSTEM
IS EXPECTED TO ACCELERATE TOWARDS THE MID-LAT.

NUMERICAL GUIDANCE IS IN GOOD AGREEMENT.