A wet start to the week
Thunderstorms affected most of Victoria on Sunday, with isolated severe thunderstorms about the south and west, including the northern suburbs of Melbourne. Central Victoria recorded significant rainfall in the 24 hrs to 9 am on Monday. It was the wettest November day in years for a few stations west of Melbourne—Meredith and Ballarat Aerodrome had their wettest November day since 1978 and 2009 respectively. The Mallee and north-central areas recorded 2-8 mm.
Spring rainfall is on track to be close to average for much of the western and northern Victoria, tending to above average in the south-west. But it has been a drier than average season for parts of the south-east. Looking over the borders, western New South Wales and much of South Australia have had a wet spring. Overall, both and days and nights have been much warmer than usual for Victoria with parts of the east on track to record their warmest spring average minimum temperature.
The rainfall outlooks for December and summer (December to February) show above average rainfall is likely across the mainland, including Victoria. Both average daytime and night-time temperatures are likely to be warmer than usual this summer for Victoria. Average night-time temperatures have a greater than 80% chance of being warmer than usual over most of Australia.
Summer rainfall outlook
Summer rainfall outlook
The main driver for the widespread wet outlook is the La Niña in the Pacific, which is likely to persist until at least the end of February 2021. La Niña typically increases the likelihood of above average rainfall across much of northern and eastern Australia during summer. Meanwhile, the Indian Ocean Dipole (IOD) is neutral, and sea surface temperature patterns in the Indian Ocean are not reinforcing the La Niña in the Pacific as strongly as they did in 2010 (Australia's second wettest summer on record).
As of 24 November, water storages in the Murray–Darlin Basin (MDB) are 62.0% full, up 23.0% since the same time last year. 2020 has seen the highest increase in water storage levels across the MDB since 2016, with increases in both the northern and southern MDB. Water storages in the South-East Coast (which covers southern and eastern Victoria) have risen 8.0% in the last year to 48.4% full. Melbourne's water storages are 75.4% full compared to 63.9% twelve months ago.