Rain and thunderstorms will affect a large portion of Australia this week as the remnants of Tropical Cyclone Tiffany spread tropical moisture across the country.

Tropical Cyclone Tiffany made landfall over the eastern Top End in the middle of last week before weakening below cyclone strength as it moves over land.

Since then, the former tropical cyclone has caused widespread and heavy rain over the Top End and Kimberley.

Rain and thick clouds are now spreading over central and southern Australia as Ex-Tropical Cyclone Tiffany moves over the Red Centre.

Image: Composite visible/infrared satellite image captured at 3pm AEDT on Monday, showing Ex-Tropical Cyclone Tiffany near the junction of the WA/NT/SA borders.

The tropical moisture brought over Australia by Tiffany will help fuel rain over part of every mainland state and territory this week.

Over the week as a whole, widespread falls of 15-30mm are likely. Some areas of SA, NSW, QLD and the NT should see more than 50mm and could have isolated areas that pick up over 100mm.

Image: Forecast accumulated rain during the next seven days (Monday to Sunday), according to the ECMWF model.

Some of this week’s rain is likely to cause flash flooding, while riverine flooding is also possible if the rain falls over already saturated catchments.

In addition to the rain, the tropical moisture will also limit solar power generation in several states and bring some welcome relief from the summer heat, particularly over the interior.

However, areas in southern Australia that don’t see thick clouds or heavy rain this week could still be quite warm and humid. Melbourne and Adelaide are both forecast to reach the high-twenties to mid-thirties between Wednesday and Sunday.