Over the last couple of days a large region of enhanced cloudiness propagated from north of Australia towards the South Pacific Convergence Zone (SPCZ). In association with the passage of the region we saw the development of several tropical cyclones. There is good evidence that these are, at least partly due, by the eastward propagation of an active phase of the Madden-Julian Oscillation (MJO). Below is an animation of the last days over this region.
Why this suspicion, well first CPC has low-level wind anomaly maps, which is showing a region of strong westerly wind anomalies north of Australia.
Second, the now famous index for monitoring MJO activity of Wheeler and Hendon (2004,
http://cawcr.gov.au/staff/mwheeler/maproom/RMM/) is showing a large index at phase 8. The corresponding map for a phase 8 disturbance is shown in the bottom right panel below. Both the CPC wind anomalies and the cloudiness over the southwest Pacific are consistent with an active MJO event in this region.
I highly recommend people to check out the link below to see the Google Earth streamlines for this region, linked below
