The passage of a low pressure system will be the cause of this instability. Moisture will also be present ahead of this disturbance. Felt temperatures could reach 35 in some areas, especially those located in southern Quebec.
Tornade(s) possible(s)
The abundant heat and humidity actually act as fuel for thunderstorms. The temperature contrast between cold air aloft and high mercury near the ground surface is a condition for the development of severe thunderstorms. This atmospheric context is ideal for the formation of supercells, and a tornado potential is therefore to be taken seriously during the afternoon. The situation will need to be monitored very closely.
The cells could form as early as late morning, but the energy will be even more present in the afternoon, accentuating the explosive potential.
Here are the sectors at risk
The instability is especially present in the St. Lawrence Valley. A moderate risk extends from Montérégie to the gates of Quebec City, including Estrie and a portion of the north shore of the river. Montreal is also one of the sectors to watch. Several of these regions are already under a watch of severe thunderstormsat present.
Torrential rains will be possible, as well as violent gusts. Large hailstones could also invite themselves into the adventure.