Rain at Melbourne Park
© Darrian Traynor/Getty Images
Rain at Melbourne Park. In the 24 hours to 9am Friday, widespread rainfall totals of 20-40mm were recorded, with 60-70mm in the upper Avoca and Wimmera catchments.

Parts of Victoria have recorded a month's worth of rain in less than 12 hours while New South Wales has been warned to batten down the hatches as strong winds and thunderstorms are forecast to continue following record downfalls in some regions.

Dean Narramore, a senior forecaster with the Bureau of Meteorology, said on Friday evening that parts of Victoria "copped a drenching" in the past 24 hours, with heavy rain across large swathes of the state. Almost 70mm fell in some parts.

Melbourne and central and western Victoria saw a deluge on Friday. "Melbourne metro itself has seen 40mm in four hours and the month's average for January is 47mm," Narramore said.

In the 24 hours to 9am on Friday, widespread rainfall totals of 20-40mm were recorded across western Victoria, with the bureau recording higher totals of 60-70mm in the upper Avoca and Wimmera catchments.

"Many locations, not only in Melbourne but right across western and central Victoria, have had a month's worth of rain in less than six to 12 hours. That rain is continuing to move towards the east with falls continuing in the 20-40mm range," Narramore said.

The heavy rainfalls have caused problems for state emergency services which said three people had been rescued after becoming stuck in rising water.

Josh Gamble from Victoria's State Emergency Service told reporters on Friday that in two of those cases people had become stuck while driving through flood waters. He said it was "disappointing" that people had ignored warnings about the dangers.

"Responding agencies put our lives and our equipment at risk trying to get to these people," Gamble said.

Gamble said the SES had responded to 576 calls for help in the past 24 hours, including 444 since midnight.

While the rain in most of Victoria was expected to clear on Saturday, the bureau still had weather warnings in place.

A flood watch remained in place for the Avoca River to the Broken River, with the bureau warning that a "deepening low pressure trough over western Victoria will cross the state later on Friday".

Meanwhile, a severe thunderstorm warning was in place for parts of the Mallee and Wimmera which may see damaging winds and heavy rainfall which could lead to flash flooding in areas including Ouyen, Rainbow, Walpeup, Horsham, Warracknabeal and Nhill.

In NSW, thunderstorms on Thursday night saw heavy rainfall across much of the state. In the central west region, the bureau recorded 98mm in the 24 hours to 9am in Condobolin, about a quarter of the town's annual rainfall average.

The falls were equally significant in other parts of the state. Temora in the Riverina recorded 56mm - the highest daily fall in a decade.

The bureau had a severe thunderstorms warning in place for the state's far west, heavy rainfall that may lead to flash flooding and damaging winds predicted in the state's far west including Wilcannia, White Cliffs, Ivanhoe and Fowlers Gap.

Strong winds were also predicted on the state's coast, including at Eden in the far south, as well as in the Hunter, Illawarra and around Batemans Bay.