A rainfall warning is out for the Wawa, White River, Nipigon, Rossport, Marathon, and Schreiber areas.
Environment Canada says they have already received heavy rain since Friday, noting Wawa is reporting 88 milimetres have fallen.
They point out that with another 25 to 44 milimetres of rain expected, the ground may become fully saturated with water.
Heavy thunderstorms are expected to develop over the area this afternoon.
The White River, Wawa and Pukaskwa Park areas are also under a tornado watch that is expected to end this evening, while Wawa and Pukaskwa Park have a severe thunderstorm watch in effect.
