Tropical Climate Update

Northern Australian monsoon has eased

This past week, a tropical low moved slowly westward from the Top End of Australia over the Kimberley and into the Indian Ocean. Some locations in the Kimberley received substantial rainfall, with isolated daily totals in excess of 100 mm (148 mm was recorded at Doongan on 25 January). Some locations in the Kimberley have reported total rainfall from the tropical low of up to 250 mm, with more widespread totals of 100 to 200 mm.

As the tropical low moved west into the Indian Ocean, the focus of the monsoon shifted west and north of the Australian continent. This has resulted in a return to drier and sunnier conditions over northern Australia, with showers and storms primarily in the afternoon and evening.

Monsoon expected to return to northern Australia this week

The Madden–Julian Oscillation (MJO) maintained moderate strength for much of the last week as it tracked eastward across the Indian Ocean, enhancing convection in the region. Although the MJO signal has weakened in recent days, climate models indicate it is likely to re-strengthen as it moves eastward over the Maritime Continent this week.  

During this time of year, an active MJO over the Maritime Continent typically enhances rainfall and cloudiness over northern Australia. It may also bring a reinvigoration of the monsoon and an increased risk of tropical cyclone development to the area. Australia’s tropical cyclone season so far has only seen one named system (Tropical Cyclone Yvette in late December), although several tropical lows have affected northwest Australia since December. The Tropical Cyclone season continues until the end of April.

For more information on the MJO, see the Bureau's current MJO monitoring information.

El Niño–Southern Oscillation remains neutral

The El Niño–Southern Oscillation (ENSO) remains neutral, with all indicators of ENSO within the ENSO–neutral range.

Climate model outlooks indicate the tropical Pacific Ocean is likely to remain ENSO-neutral through the southern summer and autumn. Most models surveyed expect the tropical Pacific Ocean to warm during this period, meaning La Niña is the least likely scenario for winter/spring 2017.  It should be noted that model outlooks that span the southern autumn period tend to have lower accuracy than outlooks issued at other times of the year. This means outlooks beyond May should be used with some caution.

See the Bureau’s ENSO Wrap-Up for official El Niño, La Niña and Indian Ocean Dipole information.