Skip to Content

News

Home>Weather News>Unusual late May deluge for northern Australia

Search Icon

Unusual late May deluge for northern Australia

Anthony Sharwood
Image: Forecast rain in northwest and central Australia up until next Wednesday, May 28, according to the ECMWF model. Source: Weatherzone
Image: Forecast rain in northwest and central Australia up until next Wednesday, May 28, according to the ECMWF model. Source: Weatherzone

The official wet season is over, but a large part of northern Australia can expect unseasonably heavy rain beginning late in the weekend and extending into the middle of next week.

At the same time as a polar airmass dumps welcome rain in parched parts of the country’s southeast with snow at higher elevations, the diagonally opposite end of Australia can expect downpours caused by a tropical airmass.

A deep stream of northwesterly winds originating near Indonesia will draw the moisture over Australia, with rainfall totals likely to be enhanced by the warmer-than-usual sea surface temperatures around WA’s North West Shelf.

It’s worth examining two different models to see how this event might play out.

The European Centre for Medium-Range Weather Forecasts (ECMWF) predicts the heaviest rain to occur in a band stretching from WA’s Kimberley region to the Northern Territory border and slightly further afield.

Image: Rainfall in parts of northern Australia for the 6-day period to Wednesday, May 28, 2025, according to the ECMWF model.

The Global Forecast System (GFS) model predicts heavy rain over a slightly smaller part of Western Australia but has opened the door for meaningful rainfall totals as far afield as western and even central Queensland.

Image: Rainfall in parts of northern Australia for the 6-day period to Wednesday, May 28, 2025, according to the GFS model.

Whatever scenario occurs, this is an unusual weather system for the last week of May, and we can illustrate its unseasonable nature with rainfall statistics from two weather stations at towns that appear on the charts above.

  • The coastal tourism hotspot of Broome sees just 27mm of rain in on average in the whole of May but is expecting as much as 80mm next Tuesday alone. 
  • The outback community of Warburton sees just 15mm on average in May but stands to exceed that total on Tuesday if heavy late showers arrive as predicted.

Whatever falls in Warburton will be very welcome, with only 18mm falling to date in 2025 and virtually nothing (just 0.2mm) over the last two months.

Note to media: You are welcome to republish text from the above news article as direct quotes from Weatherzone. When doing so, please reference www.weatherzone.com.au in the credit.