Invest 96S / Invest 90S
Sunday, January 15, 2023

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

Current Tropical Cyclones:

There are no tropical cyclones at the time of this writing

 

South Indian Ocean

>>> There’s an area of disturbed weather, being referred to as Invest 96S…which is located approximately 380 NM southeast of Diego Garcia.

Animated enhanced infrared satellite imagery depicts an exposed low level circulation center (llcc) with weak convection offset to the west. Another image reveals an exposed llcc with weak fragmented banding wrapping into the center.

Upper-level conditions have improved with moderate equatorward outflow aloft, low (10-15 knot) easterly-northeasterly vertical wind shear, and warm sea surface temperatures.

Global models struggle to resolve the formation of Invest 96S as well as 90S, however they generally agree that 96S will have slow development as it meanders west-southwestward towards Madagascar over the next 24-48 hours.

Maximum sustained surface winds are estimated at 20 to 25 knots.

The potential for the development remains medium.

>>> There’s a second area of disturbed weather, being referred to as Invest 90S…which is located approximately 650 NM north-northeast of Mauritius.

Animated enhanced infrared satellite imagery depicts a consolidating low-level circulation with formative convective banding over the southwestern quadrant and flaring convection obscuring the center. A microwave image reveals fragmented convective banding wrapping around the periphery into the southwest quadrant of a broad low level center.

Upper-level outflow has improved over the past day with poleward outflow aided by an upper-level shortwave trough to the south and persistent broad equatorward outflow. However, moderate to high (20 to 25 knot) easterly vertical wind shear will slow development over the next two days. Sea surface temperature values remain conducive.

Global models have struggled to resolve the formation of Invest 90S as well as Invest 96s, which is 1000 NM to the east, however, the GFS run indicates 90S will become the dominant system as it tracks towards northern Madagascar. ECMWF favors Invest 96S but indicates a similar track toward northern Madagascar.

Maximum sustained surface winds are estimated at 20 to 25 knots.

The potential for the development is upgraded to medium.