Threat for thunderstorms continues into the long weekend

Mother Nature put on an incredible light show late Thursday night on Ile Perrot. I managed to capture this shot looking south towards the Saint Lawrence River. The storm produced no damage in my community, but put down a quick 10mm of rain in less than an hour. Hail occurred across parts of the West Island. (Valley Weather Photo)

A Severe Thunderstorm Watch has been posted Saturday for metro Montreal and southern Quebec. The watch has been issued rather early due to the amount of camping, boating and other activates planned this holiday weekend. If you have any outdoor plans today, keep a close eye to the sky this afternoon.

Happy Canada Day long weekend. Summer seems to have finally arrived across southern Quebec. A warm and humid air mass has been in place for most of this past week, with daily rounds of showers and thunderstorms. The storms late Thursday produced spectacular lighting across the western portion of Montreal including here on L'Ile Perrot. The storms also generated some small hail across the West Island, specifically in Pointe Claire. Other parts of the province also had severe storms, with funnel clouds and hail reported. The isolated nature of thunderstorms cells meant some location in southern Quebec received quite a bit of rainfall, while other spots nothing at all. Case in point, I measured close to 16mm of rain from late Thursday into Friday, while Trudeau Airport 20km northeast of my location had only 1.4mm.

Severe weather outlook for this Saturday from Environment Canada.

In terms of temperatures, the daytime hours have been quite muggy, with highs approaching 30C (85F), but the nights have been comfortably cooler, with a good breeze. The holiday weekend will be rather unsettled through Sunday, however Monday looks sunny, warm and less humid. Saturday will feature a renewed threat for strong thunderstorms, especially south and east of Montreal. Some of the storms will produce strong winds, hail and torrential downpours. More showers and thunderstorms can be expected Sunday, but they likely will be of the non-severe variety. Highs will be near 28C (83F) Saturday, but cooler Sunday in the clouds and showers, 23C (73F).

Looking ahead to next week, high pressure will build in for a dry and sunny start to the work week. By Wednesday, the air mass will become increasingly humid and unstable, originating from the Gulf of Mexico, with showers and thunderstorms firing up late in the day Thursday and Friday. Temperatures will rise to near 30C (86F) from the latter half of the week into the weekend. We may even record out first 32C (90F) day of the season in Montreal by late next week.