Storm's a brewin' for southern Quebec again — heavy rain, possible flooding forecast

One week after powerful thunderstorms swept through southern Quebec and on the eve of Quebec's construction holiday, Environment Canada is warning of more rain in the forecast. 

The agency issued a special weather statement for Montreal and most regions in the south of the province on Thursday morning that said heavy rain was expected to fall on Friday and Saturday and more thunderstorms could roll through the area. 

Forecasters expect the system to arrive Friday morning, bringing with it between 30 and 50 millimetres of rain. Last Thursday, the storm that hit the city dumped 85 millimetres of rain in just a few hours, enough to overwhelm drainage systems, overflow sewers and flood some homes and roads. 

The weather expected Friday and Saturday could bring similarly violent storms, the agency warned. 

"Heavy rain may cause flash flooding and ponding on roads," the special weather statement said. "Localized flooding is possible in low-lying areas."

The weather is arriving just as Quebec's construction holiday is set to begin, when thousands of Quebecers depart on vacation.