A forecast of heavy rain in waterlogged central Canada and in both the Atlantic and Pacific regions has residents and emergency officials bracing for flood conditions through Friday and the weekend.
Environment Canada has issued a rainfall warning for much of southern and eastern Ontario, where some communities could be soaked with 50-90 millimetres of rain through Saturday.
But with the ground already saturated after weeks of rain and spring runoff, the agency says there may be new or additional flooding in many areas.
"All parts of Toronto can be affected by flooding and there may be little or no advance warning that localized flooding is imminent," the City of Toronto warned in a news release Thursday.
The city has also warned that the heavily-travelled Don Valley Parkway through the heart of Toronto could be shut down on Friday afternoon should the adjacent Don River overflow its banks.
Recent rain and spring runoff have already caused a significant rise in water levels in Lake Ontario, causing some shoreline erosion and localized flooding east of downtown Toronto.
Environment Canada has also issued a special weather statement for much of Quebec, where numerous communities are already coping with overflowing rivers, particularly north and south of the Montreal area and in western Quebec.
The agency says another 30 millimetres of rain is likely north of the St. Lawrence River through Sunday while the Montreal area can expect slightly lesser amounts.
Eastern Quebec is also beginning to experience flooding due to the rain and melting snow.
Quebec Premier Philippe Couillard said Thursday that 132 municipalities and some 1,400 residences are affected by or threatened by rising waters .
"We know that the water level will not drop in the next few days. It is more likely to remain high, or even continue to rise," he said.
Environment Canada has also issued a special weather statement for a large swath of southern B.C. due to the potential for severe thunderstorms, saying conditions are favourable for the development strong wind gusts, large hail and heavy rain.
It said heavy rain associated with the storms, combined with snow melt, will lead to rising river levels and could increase the risk of flooding.
The wet weather will also take aim at Atlantic Canada starting Friday night and continuing through the weekend.
Environment Canada has posted special weather statements for most of Nova Scotia warning of 50-to-100 millimetres of rain through the weekend while southwestern New Brunswick can expect around 50 millimetres of rain and northwestern areas may receive 20 to 30 millimetres.
The agency the additional rain will exacerbate current flooding and advises residents near the Saint John River and its tributaries to remain on alert.
