Environment Canada has issued a Special Weather Statement for much of northwestern Ontario.
There is the potential for significant rainfall amounts Monday and Tuesday.
Additional rainfall amounts of 10 to 25 millimetres are possible by this afternoon with locally higher amounts of 25 to 50 millimetres possible in thunderstorms.
Another round of precipitation is expected to move in from Minnesota Monday night and will likely persist into Tuesday.
Environment Canada says rainfall amounts in this second round still remain uncertain but an additional 20 to 40 millmetres seems possible at this stage, with higher amounts expected in thunderstorms.
Officials stress there still remains uncertainty in precipitation timing and amounts.
