Published on June 23, 2023 at 11:00 p.m.
The national holiday takes place under the threat of violent storms in several sectors. forecasts.
Stormy potential for the national holiday
National Day celebrations could be paused on Saturday. North of the river, the passage of a cold front leads to an increase in air mass. In the southern parts of the province, it is the humidity that can lead to violent storms.
Lots of humidity in the air
The passage of a cold front provides uplift potential for areas further north. Isolated storm cells are forming in a line stretching from Outaouais to Sept-Îles and passing through Saguenay-Lac-Saint-Jean during the afternoon. This risk will disappear in the evening.
As for the areas further south, the presence of a hot air mass coupled with the introduction of a new system also brings some inconveniences. Estrie and Beauce are at risk of overlapping thunderstorms. This risk extends to Montreal and the National Capital Region.
Good to know: A storm cell is considered isolated if it erupts in previously clear skies. It is often short-lived and the sky clears up immediately. A nested thunderstorm usually forms at the core of a system when the sky is completely cloudy.
Lots of rain for the south
This air mass contains a high water vapor content. During thunderstorms, there could be heavy rain in places. Significant accumulations of water are possible in the event of heavy rainfall.
Note that small hailstones can fall forming storm cells. In Estrie, hailstones with a diameter of two centimeters are possible, which corresponds to a five cent piece.