A rainfall warning is in effect for Toronto and many other regions across southern Ontario with Environment Canada calling for up to 50 millimetres of rainfall over a period of less than 24 hours.

In its advisory, the national weather agency said showers will likely begin on Tuesday afternoon.

“Showers are expected to push into the region through the afternoon as a moisture laden system moves into the Great Lakes Basin. The showers are expected to become more widespread and heavy at times tonight along with the risk for thunderstorms as a more unstable air mass moves in,” Environment Canada said.

The rain will continue into Wednesday but will become “more isolated” and will “ease off in intensity.”

Some areas could see “in excess of 50 mm” but Environment Canada said there still “remains a high degree of uncertainty.”

“Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible,” the advisory said.

CP24 Meteorologist Bill Coulter said that while this model may be showing intense periods of rain, CP24's model is showing more "moderate" periods of rain in the afternoon and evening hours. 

"I think, in this case, we need to get a little bit closer to the start of the event to see exactly who will be impacted and how much but 50 mm would be a significant impact," he said. 

"Our models suggest it is more rounds of moderate rain but not quite up to that amount, which would cause much more significant problems out there on the roads and waterways." 

After experiencing one of the wettest summer's on record, Toronto saw a particularly long stretch of dry conditions earlier this month. Those dry conditions came to an abrupt end this week as more wet weather arrives.

Sunshine and mild temperatures are expected to return later this week and a brighter weekend is on tap for the city.