Strong thunderstorms - turning much cooler for southern Quebec

A spectacular sunset in Terrasee-Vaudreuil after a glorious Victoria Day Monday across southern Quebec. Skies were crystal clear all day along with light winds, low humidity and a high of 21C (70F). (Photo Tammy Arbour)

There is a risk of strong to severe thunderstorms this afternoon across the region.

It is a very warm and muggy morning across southern Quebec this Wednesday after a mild overnight. Early morning temperatures did not drop below 21C (70F) across the region. Clouds will mix with sun to start the day, followed by an increase in coverage of showers and isolated thunderstorms by early afternoon. It will be a very windy day, with gusts out of the southwest between 30 and 50km/h, increasing to 50 to 70km/h this afternoon.

The weather will be warm and humid today, with temperatures approaching 30C (86F) by early afternoon in Montreal. A rather vigorous cold front is forecast to cross the region late in the day. Ahead of the front, a line of showers and thunderstorms is expected to develop and move across the region from northwest to southeast. Some of the storms have the potential to become rather strong, with gusty winds being the main threat, but also small hail, dangerous lightning and heavy rainfall. The storms should taper off by sunset, with just a few scattered showers into the overnight period. We need any rainfall we can manage, as just 8.6mm has fallen at Trudeau Airport in May. If this holds, it will break the record for the driest May set back in 1982 when only 12mm fell.

Skies will clear out on Thursday, the weather will turn much cooler and drier, with daytime highs near 17C (63F). Overnight lows will drop down into the single digits Thursday night, with a risk of frost away from the urban areas. High pressure will dominate the weather into the weekend, with mostly clear skies along with slowly warming temperatures.