Meteorologist Michael Efron said a low pressure system from South Australia would pass over Victoria moving easterly on Thursday evening and Friday morning.

He said Wimmera and North Victoria would experience the heaviest rainfall, with potential thunderstorms restricted to the north of the state.

Mr Efron said Victorians and Wimmera residents would experience moist air with the change caused by a tropical system, with falls of 10 to 40mm overnight Thursday into Friday morning.

He said showers would mostly clear by Friday afternoon with temperatures in the low twenties expected. 

The bureau issued a brown rot warning to Wimmera and Mallee fruit growers. 

“Stone fruit growers in the Mallee, Northern Country, North Central, North East, Central and East Gippsland forecast districts and parts of the Wimmera, South West and West and South Gippsland forecast districts are advised that rainfall and accompanying high humidity during Friday may be conducive to an outbreak of brown rot. The humidity should rapidly decrease later on Friday.,” they advised.

Mr Efron said showers would clear by the weekend.

“We’re looking at a mostly dry weekend with temperatures gradually increasing,” he said.

Mr Efron said by Monday temperatures should return to mid to high 30s in North Victoria, potentially reaching into the 40s.

The State Emergency Service advises that people should: 

* Don't walk, ride or drive through flood water; 

* Keep clear of creeks and storm drains; 

* Be aware that in fire affected areas, rainfall run-off into waterways may contain debris such as ash, soil, trees and rocks; 

* Be alert that in areas recently affected by fires, heavy rainfall increases the potential for landslides and debris across roads;