Taking a closer look at mesoscale processes in the tropics, satellite imagery shows convection is now steadily shifting eastward over the Maritime continent. The MJO (Madden Julian Oscillation) phase space diagrams indicate wave progression into octant 5 as of 9/12. This is after a long lingering in stage 2 which influenced the burst of tropical activity in the last week of August. The signal is growing stronger with nearly a 2 sigma projection. The latest MJO wave is being amplified by constructive interference by phase 4 of the GWO (Global Wind Oscillation). Main question is whether it can progress into octant 6 which is currently not supported by the forecast models. At this point it appears it will pass through the <1 sigma region before emerging in phase 8 by the start of October. The continued positive phase of the IOD (Indian Ocean Dipole) should help keep the MJO wave at least somewhat apparent as it progresses into the western hemisphere.

We'll be looking at the next MJO wave beginning late this month (23-28), with phase 2 coming up in the beginning of October. I would expect another resurgence in tropical activity around October 5 to 14. Between now and then looks quiet.