Read the latest here: Quick-moving storm crosses province

The weather could go from scorching to severe this afternoon as both a severe thunderstorm watch and a heat warning are simultaneously in effect for the Montreal region.

There is a risk of a tornado with high gusty winds and heavy rain developing as severe thunderstorms are expected to develop over the next few hours.

Environment Canada’s heat warning remains in effect– extending through Laval and the South Shore – with a forecast high of 30 degrees. With the Humidex, it will feel more like 38, in the tail end of this record-breaking ‘second summer.’

The thunderstorm watch extends to the same area – and the cold front is moving in faster than expected as very cold air moves in on the current tropical air flow.

That front will come through the area from the north around 4 p.m. Wednesday, and could bring all sorts of severe weather including the possibility of hail, high winds, downbursts and tornadoes.


Environment Canada says the storms will move over areas near the St. Lawrence River around supper time.

Montrealers can also expect a good bit of water accumulation, because the the rain is expected to last until 10 p.m.

Environment Canada is reminding people to head indoors if this severe weather occurs. People are also advised to take precautions: strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles. Intense lightning is likely with any thunderstorm that develops, so it's important that people take cover and exercise caution.

After the storm, temperatures are expected to soon return to seasonal for southern Quebec.

Friday and Saturday are expected to be especially cool – some regions might even experience frost.