A surge of tropical moisture will produce rain over part of every Australian state and territory during the next week, with some places likely to see several months’ worth of rain in a few days.

Rain and thunderstorms will increase over the north of WA this weekend as tropical moisture feeds into a deepening area of low pressure. This wet and stormy weather will then spread over central Australia on Monday before forming a broad rainband that will drench southeastern and eastern Australia between Tuesday and the end of next week.

The maps below show how much rain two different computer models are predicting over Australia during the 7-day period starting this Friday.

Images: Forecast accumulated rain during the 7 days starting Friday, September 20, according to the ECMWF (top) and GFS (bottom) models.

This weather system will cause a nation-wide soaking that could last for around seven to 10 days. Some areas in WA and the NT that typically receive 20 to 50 mm of rain in September could pick up about 50 to 100 mm from this event.

The widespread nature of this rain event also increases the risk of flooding and travel disruptions in multiple states. Anyone travelling by road or rail in the next couple of weeks should keep an eye on the latest warnings and road/rail conditions across the country.