AWIO20 FMEE 251041
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST
INDIAN OCEAN
DATE: 2010/10/25
AT 1200 UTC
PART 1 :
WARNING SUMMARY : Nil.
PART 2 :
TROPICAL WEATHER DISCUSSION
:
The Near Equatorial Trough (NET) is rather active East of 50E and
north of 10S. The convective activity is moderate between 50E and
70E ans East of 80E :
- At the western edge of the NET, surface obs, scatterometric data
(METOP) and satellite imagery
reveal a completely exposed and bad defined low level clockwise
circulation approximately centered at 0900Z near 4.5S and 55.8E
over the Seychelles Islands. Associated convective actvity is
scattered and mainly exists over the eastern part of the
circulation which shifts generally westwards at about 10 kt. Winds
are estimated at about 10-15 kt thanks to Ascat swath with MSLP at
1008 hPa (observations of Mahe). This system has no potential for
intensification.
- East of 80E, the system followed since two days began to
organize. It still undergoes a moderate to strong easterly vertical
wind shear and the low level circulation is well exposed. Deep
convection is present over the western part of the system. At
0930Z, it is located near 9.6S/86.6E with MSLP at 1006 hPa and
winds reaching 15/25 kt in the southern semi-circle due to gradient
effect with the subtropical high pressures located in the South.
The movement is west-southwestwards at 6 kt. The equatorwards low
level inflow is worse that yesterday, but is good polarwards. The
system is expected to track southwestwards and then
west-southwestwards. Vertical wind shear should weaken
progressively up to 24 hours, as the system comes nearer the upper
level ridge axis located in the South. For the next three days, SST
remain at about 27 C and beyond become cooler. According with this
conditions, available NWP models forecast a slow intensification
during the next 72 hours.
For the next 24 hours, potential for the development of a tropical
depression
is poor to fair, and becomes good beyond

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