As the sun rose on Wednesday morning, a large mass of cloud was draped over the eastern half of Australia. This is a scene that was notably absent during 2019 and one that is likely to bring smiles to many Australian faces.

Image: Cloud over Australia on Wednesday morning.

During the next three days (Wednesday to Friday), rain will spread across large areas of northern, central and eastern Australia. This multi-day and multi-state rain event is occurring as the remnants of Tropical Cyclone Esther injects a mass of tropical moisture into a deepening low pressure trough.

Computer models are still having trouble figuring out exactly where, when and how much rain will fall from this dynamic system. However, it's likely to deliver falls of 20-40mm over large parts of the eastern NT, western Queensland, northeastern SA, NSW, the ACT, eastern Victoria and eastern Tasmania between Wednesday and Friday, with some places expected to see more than 100mm. Flood watches have been issued in most of these states and territories for the coming days.

Image: Accumulated rainfall predicted between Wednesday and Friday by the ECMWF-HRES model.

Weather patterns like this one were absent last year, which helped make 2019 the driest year on record for Australia as a whole and in the Murray Darling Basin.

Fortunately, two of the climate drivers that underpinned last year's severe lack of rainfall - a positive Indian Ocean Dipole (IOD) and negative Southern Annular Mode (SAM) - both broke down at the beginning of 2020. This shift in climate drivers saw a change in the weather patterns over southeastern Australia, with a return of more frequent and heavier rain during the last couple of months.

While February was a good month for rain in eastern NSW and parts of southern Queensland, many areas further west missed out. This month, almost all of NSW, northeast Victoria and southwest Queensland should receive at least some rain during the opening week of March.

But while this week's rain is welcome, it's unlikely to be drought-breaking across the parched Murray Darling Basin. During the 24 months to February 2020, most of the Basin had accumulated rainfall deficits of more than 300mm. Some areas in the east, stretching from Queensland down to Victoria, were running more than 600mm below average at the end of this two-year period. It's going to take multiple months of above average rain to make up for these deficiencies.

Image: Rainfall deficiencies over the Murray Darling Basin during the 24-month period ending in February 2020. Source: Bureau of Meteorology.

Thankfully, this month will go some way to replenishing the missing water across Australia's southeastern inland and its another step in the right direction. After this week's rain, there's a good chance that March will be the second consecutive month with above average rain in the Murray Darling Basin, ending a 10 month run of drier-than-usual months up to January this year.