Much of our moisture originates from the tropics this time of year. The chart below shows a pulse of moist air in Phase 5 over Australian longitudes (green line) around 10-14 January. Tracking this tropical moisture can help us understand when rain-bearing systems or heatwaves are more likely.

The Madden – Julian Oscillation (MJO) is a tropical disturbance that moves eastward around the global tropics every 30-60 days and has proven to influence rainfall and temperature conditions. The strength of the MJO may increase or decrease as it progresses eastwards, affecting the level of convection and influence on both precipitation and temperature. The diagram below is used by scientists to track the path of the MJO showing predicted dates through various phases (see last weeks edition for MJO explainer). This illustrates the MJO currently inactive inside the circle, then increasing in strength through week 2 in January as it reaches the maritime continent. Not all models are aligned and some show no signal for the MJO whatsoever. A short YouTube cartoon explaining the MJO can be found here