Heavy rainfall and more freezing rain expected in the GTA, surrounding areas on Wednesday

The Greater Toronto Area and other parts of southwestern Ontario could see heavy rainfall and freezing rain on Wednesday, Environment Canada says, as a second spring storm hits the region in less than a week and threatens to cause more power outages. 

Environment Canada issued a rainfall warning for the City of Toronto, Oakville, Mississauga and Brampton early Wednesday, forecasting the downpour may cause flash floods and water pooling on roads.

Between 30 to 50 millimetres of rain may fall, starting in the morning and continuing into early Thursday morning. 

"With thunderstorms expected, rainfall amounts may exceed 50 mm over some areas, particularly over southwestern Ontario," Environment Canada said. 

These areas are also under a special weather statement for freezing rain, which Environment Canada says will last a "brief period" Wednesday morning or afternoon before transitioning into rain.

The federal weather agency did not specify how much freezing rain is expected to fall, but said "minor" ice build up is possible on some surfaces, which could make roads and sidewalks icy, slippery and hazardous. 

Other parts of southwestern Ontario are under both rainfall and freezing rain warnings — though Environment Canada said the freezing rain "will not be nearly as significant as the ice storm from this past weekend." 

The following areas are expected to see 2 to 4 millimetres of freezing rain starting Wednesday morning and continuing into the evening: Vaughan, Richmond Hill, Markham, Pickering, Oshawa, southern Durham Region, Halton Hills, and Milton. 

Between 4 to 8 millimetres of freezing rain is possible in Newmarket, Georgina, northern York Region, Orillia, Lagoon City, Washago, Uxbridge, Beaverton, northern Durham region, Bracebridge, Gravenhurst, Barrie, Collingwood and Hillsdale. 

In these harder hit areas, freezing rain will again begin Wednesday morning and continue into the evening. 

"As temperatures rise above the freezing mark, freezing rain will transition to rain this afternoon. For locations over higher terrain, freezing rain may linger into early this evening," Environment Canada said. 

Areas that are under freezing rain warnings could also see easterly winds between 50 to 60  kilometres an hour, which may worsen any tree damage, the federal weather agency said. 

People are advised to take care when walking and driving as surfaces may become icy and slippery. 

Power utility Hydro One says crews have been working around the clock since the last storm blew through, knocking out power to hundreds of thousands of homes across southern and eastern Ontario.