Environment Canada has issued a severe thunderstorm watch for the City of Toronto as a cold system approaches our hotter-than-usual region, threatening an atmospheric clash of epic proportions.

Damaging wind gusts, torrential downpours, frequent lightning and hail are all in the cards for late Tuesday afternoon and evening, according to the federal weather agency.

There is also the risk of "an isolated tornado" forming as scattered storms make their way throughout the GTA.

Today's heat and humidity will give way to a much colder, wetter system by this evening. Image via Environment Canada.

"Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles," warned Environment Canada in an emergency alert issued Tuesday afternoon.

"Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors!" the alert continues. "The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches."

Thunderstorms should clear overnight, but showers are expected to persist straight through to Friday morning.