Toronto and the GTA could get pummeled with as much as 50 millimetres of rain on Thursday and Friday.

“The storm is a complex one,” CityNews meteorologist Natasha Ramsahai said.

It could include “rain, thunderstorms, snow, freezing rain, wind, and then falling temperatures once the system finally exits.”

Due to the rain and above-zero temperatures, a provincial flood watch is also in effect, the Ministry of Natural Resources said Thursday afternoon.

Environment Canada first issued a rainfall warning of 25 to 50 mm on Wednesday. Niagara, Hamilton, Halton, Peel, York and Durham are also affected.

680News meteorologist Jill Taylor said there will be increasing cloudiness in Toronto with showers beginning around 2 p.m. on Thursday. There could be a brief period of freezing rain or ice pellets, Taylor said, with winds of up to 32 km/h.

There’s a high of 3 C in the forecast, rising to 6 C overnight with a chance of thunderstorms.

Click here for the full forecast.

The most rain will fall in the Windsor-Sarnia to Niagara-Hamilton corridor, Environment Canada said, followed by the north shore of Lake Ontario. In addition, thunderstorms will be possible over Southwestern Ontario and the Golden Horseshoe.

Two weather systems, one from Alberta and one from Texas, are tracking toward the Great Lakes.

The systems will bring warming temperatures to the area and will likely cause snow to melt, meaning ponding and flooding will be a concern.

Rivers and streams could also become more dangerous due to rising water levels.

Residents are advised to clear their catch basins and to keep small children and pets away from fast-moving water.

Click here for City of Toronto information on how to guard against — and recover from — a flooded basement.

sewer

Several sewers in Toronto are covered with ice. CITYNEWS/Bert Dandy

don-river

Some parts of the Don River are covered with snow and ice, while other parts have melted. CITYNEWS/Bert Dandy