Tropical Climate Update

Hot and dry conditions continue over northern Australia

Monsoon break conditions became well established over tropical Australia during the last week. Rainfall totals were relatively low and rainfall coverage was patchy over much of the north, while temperatures were significantly above average. This continues the recent rainfall and temperature trend observed over northern Australia during the current wet season, since October 2015.

The current monsoon break has coincided with the eastwards progression of a moderate-strength pulse of the Madden–Julian Oscillation (MJO) out of the Australian region. As the MJO moves eastwards over the Pacific Ocean, rainfall for northern Australia typically transitions from above to below average. While northern Australia experienced relatively dry conditions, much of South East Asia saw above-average rainfall during the last week due to the presence of a weak monsoon trough to the north of Australia.

In recent days the MJO has weakened. Climate models indicate the MJO will remain weak during the next week or two, possibly re-appearing in the tropical Indian Ocean in mid-April. The next pulse of the MJO is unlikely to affect Australian longitudes before late April. Based on these model MJO forecasts and climatology, the likelihood of a monsoon burst for northern Australia before the end of the current wet season is considered low. The likelihood of further tropical cyclone activity across the Australian region is also considered low in this scenario. Australia has recorded only three cyclones to date this tropical cyclone season. This is well below the season average of eleven, and less than the record-low of five since accurate satellite measurements commenced in the 1970s.

See the Bureau's MJO Monitoring for current MJO information.

El Niño decline continues

While the Pacific Ocean remains warmer than average, it continues to gradually cool. Both sea surface and sub-surface temperatures have fallen substantially since their peak in late 2015. Key atmospheric indicators of El Nino have also displayed a weakening trend recently. Climate models indicate neutral conditions and La Niña are equally likely in the second half of 2016.

While the breakdown of a strong El Niño is often associated with above average rainfall over parts of southern Australia, northern Australia typically experiences less rainfall than average overall. Warmer-than-average daytime temperatures are typically also a feature for northern Australia during the demise of El Niño.

See the Bureau of Meteorology's ENSO Wrap-Up for official El Niño information.