AWIO20 FMEE 131140
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST
INDIAN OCEAN
DATE: 2011/02/13 AT 1200 UTC
PART 1 :
WARNING SUMMARY :
Warning WTIO30 and WTIO22 n 017/05 issued for
Intense Tropical Cyclone BINGIZA. Next warnings will be issued at
1200Z
PART 2 :
TROPICAL WEATHER DISCUSSION
:
Tropical Cyclone BINGIZA :
Position at 0900Z: 15.8S/52.3E at 656 km North-West of La Reunion
and 194km
East of eastern Malagasy coastline.
Motion: Westwards 5kt overt the past 6 hours
T=4.5+ and Ci=5.5
Max wind: 90kt
Estimated MSLP: 953 hPa.
Evolution within the next 24 hours :
Tropical Cyclone should concern a broad northern half of Madagascar
, directly (eastern coastline) and undirectly in a first step
(Mozambique Channel coastline).
Heavy rain directly linked to the System should progress over the
north and the northeastern part of
Madagascar.
Bingiza is expected to make landfall within Monday early between
Antalaha and Toamasina.
Over this coastal region, winds will progressivily increase and
gusts should exceed 100 km/h on and after this afternoon and
locally exceed 150 km/h within next night up to 80 km from the
center.
The area of Masoalina Peninsula, Antongil bay and Sainte-Marie
island are especially threatened.
Uncertainty at 75% for this range Tau 24h (linked to this landfall
forecast) is between 100 km (build thanks to Ensemble System) and
140 km (Climatological Direct Positionning Error) on both sides of
the forecast RSMC's track - supposed to be the most probable -
Crossed Point near
Antanambe.
More Northern and Southern areas than the above targetted ones
should therefore concern by the strongest winds (refer to the
followings issues of the RSMC's forecast track).
On the Mozambique Channel area, thundery and heavy rain activity is
expected to increase between 7S and 20S in relationship with
peripheral bands associated with Tropical Cyclone Bingiza.
Westerly winds should increase over Mayotte and Comoros with strong
gusts under squalls.
Further Evolution :
In relationship with the overland (crossing east to west )
Madagascar track , winds are expected to rapidly decrease near the
residual circulation center but heavy rain activity should still
exists up to 400km to 500 km from the center.
Bingiza's remnants should come back over sea at weakened stage on
tuesday between Mahajonga and Morondava.
In relationship to very good environmental conditions over
Mozambique Channel, re-intensification is then expected.
For further details, see Warning WTIO30 and WTIO22 n 017/05 and
followings.
Elsewhere over the basin :
Last
Meteosat 7 satellite imagery shows 2 low level clockwise
circulations. The both are totally exposed in relationship with an
easterly moderate vertical windshear north of 17S and east of 60E.
- The western suspect low shows a well defined low level vortex

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centered at
0900Z near 14.4S/64.7E at about 600 km on the
Nord-Nord-East of Rodrigues Island.
MSLP is estimated at 1002 hpa without convective activity and
rapidly fill in (Buoy nr14540 measured
999.5 hPa at 12/2300Z).
Maximum winds near the center are estimated at 20/25kt thanks to
Ascat 13/0434Z swath.
This low is expected to drift southwards towards more favourable
environemental conditions. Some available NWP models forecast a
significative deepening of this low on and after tuesday.
- The other suspect low is bad defined and is centered at
0900Z near 13.2S/73.6E.
MSLP is estimated at 1006hPa with winds near the center at about
15/20kt (Jason 13/0157Z swath). There is no potential for
intensification.
For the next 48 hours, development of another tropical depression
is not expected (except Binziga back over Sea) .
The potential becomes poor on Tuesday in relationship with the low
located in the north of Rodrigues island.

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