There is a new area of interest in the South Indian Ocean, a disturbance has been present over the past couple of days and has showed increasing signs of organization. The area has been labelled as Invest 98S and looks to become our next tropical storm in the South Indian Ocean. A TCFA (Tropical Cyclone Formation Alert) was recently issued, and has 98S heading in a South-West direction while intensifying and undergoing its formation process.

The comments from the TCAF are as follows:

WTXS21 PGTW 082330
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 12.9S 69.9E TO 15.8S 60.8E WITHIN
THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF
NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA
ARE ESTIMATED TO BE 28 TO 32 KNOTS. METSAT IMAGERY AT 081930Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 13.2S 69.1E. THE
SYSTEM IS MOVING WESTWARD AT 07 KNOTS.

2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 13.0S
69.1E, IS NOW LOCATED NEAR 14.0S 67.0E, APPROXIMATELY 480 NM SOUTH-
SOUTHWEST OF DIEGO GARCIA. RECENT ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS SIGNIFICANT IMPROVEMENT IN THE CONSOLIDATION OF THE
LOW LEVEL CIRCULATION CENTER (LLCC). BANDING CONVECTION HAS BEGUN TO
DEVELOP AROUND THE LLCC, WITH DEEPER CONVECTION PERSISTING OVER THE
LLCC. A RECENT 082123Z AMSU-B PASS SUPPORTS THE BANDING OBSERVED IN
IR IMAGERY. UPPER-LEVEL ANALYSIS INDICATES THE DISTURBANCE IS
APPROXIMATELY 05 DEGREES EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS
UNDER WEAK (10-15 KNOT) VERTICAL WIND SHEAR WITH GOOD DIVERGENCE
ALOFT. SEA SURFACE TEMPERATURES IN THE AREA ARE APPROXIMATELY 28-29
DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28
TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002
MB. DUE TO THE IMPROVING IR SATELLITE SIGNATURE, FAVORABLE SURFACE
CONDITIONS AND GOOD UPPER-LEVEL OUTFLOW PATTERN DEVELOPING, THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.

3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
092330Z.//
NNNN

Once a TCFA is issued it is a good indication that the system in question warrants watching, and if the model runs are anything to believe it does warrant attention.

The GFS has been consistent in the past week with the development of Invest 98S and has also shown consistency in the path it takes. The GFS is indicating that 98S will begin to intensify over the next few days and reach what looks to be tropical storm strength before making landfall in about a week into the northern East Coast of Madagascar. It then moves the invest, or what will likely then be tropical storm Giovanna. Giovanna being the next name to be used on the South West Indian Ocean name list for 2012.

The GFS then moves a weakening Giovanna, over Madagascar and into the Mozambique Channel. If the storm manages to cross Madagascar without losing its low level circulation, a quick spin-up is possible once into the channel. The GFS shows a bit of re-intensification taking place once in the Mozambique Channel and then impacting the middle East Coast of Mozambique as what looks to be a weak tropical storm. Though even a weak tropical storm can pose a large risk for flooding.

It is important to remember that this storm is still a while out from landfall and hasn’t even developed yet so there is no certainty as to what it may do, but I will provide updates as I did with Funso over the next week or so as we watch 98S develop.