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.

Summer arrives in Montreal - right on schedule

The wrong place at the wrong time: Gusty winds over the last few days along with a very wet spring, helped this large tree on Monteith in Verdun to loose a section late Friday. The huge branch took out a fence and crushed this KIA. It is a warning to all homeowners to inspect there trees for damage or wear and weaknesses in the branches. (ValleyWeather Photo)

Summer officially arrived at 11:54 on Friday morning, and along with it came the best weather of the year in Montreal. The weekend has been nearly perfect with partly sunny skies, low humidity and very pleasant temperatures. The only bug in the forecast was a smokey high level haze from the western Canadian wildfires. The strong northwest flow aloft is carrying the smoke into eastern Canada at the highest levels in the atmosphere. The smoke will likely be around Sunday and Monday as well. Most will not even notice. Temperatures will warm to the upper 20's both days, with overnight lows in the middle teens.

A change in the weather arrives late Monday and Tuesday, with the arrival of a frontal system from the Midwest. Clouds will be on the increase, along with showers and perhaps an isolated thunderstorm. The thunderstorms have been few and far between this year, a strong indication of just how cool it has been in Montreal. To date, I have recorded only one at my home here on Ile Perrot. That may change later this week as the first warm and humid air mass of the season arrives by Wednesday. Daytime highs will be around 27C (81F) each day with muggy overnight lows in the upper teens. There will be a risk of afternoon convective showers and thunderstorms each day into next weekend.

Summer snow fell across portions of Alberta, B.C. and northern Montana on Friday. (Photo: Elizabeth Jones)

Summer Snow
Just a side note on the bizarre weather that has occurred across Canada this spring. Flooding, tornadoes, ice storms and now a snowstorm on the first day of summer. Parts of the Rockies in Alberta and B.C. had as much as 25cm of heavy wet snow on Friday. A childhood friend of mine from B.C. posted this photo on Facebook, taken in Elkford, B.C.

Wet weekend ahead for Montreal

With the exception of Grand Prix weekend, sunny days have been at a premium this spring in Montreal. More cloud cover, showers and even a rumble or two of thunder are possible from late Thursday into Monday.

With a ton of outdoor events scheduled this weekend from weddings and garage sales to car shows, I wish I had better news. A series of low pressure systems will impact the southern portion of the province as well as eastern Ontario, with showery weather from late Thursday through Sunday. While the weekend won't be a complete washout, it will be wet at least half the time. We may see less shower activity Sunday, but it will remain cloudy.

Along with the cloud cover and precipitation will come cooler than normal temperatures for Friday and Saturday. Overnight lows will be in the 14C (57F) range, with daytime highs around 18C (65F). The normal high for this time of year is 24C (76F).

By Sunday, slightly warmer air will begin to filter into southern regions of Quebec and Ontario. If we manage to see a break or two of sun, the temperature may rise into the lower 20s. More showers are possible Monday before high pressure moves into the region. Sunny, warmer weather is expected for Montreal by next Tuesday as temperatures rise back to normal values.

So far this June, Montreal has received 34mm of rain, keeping the trend of our cool, wet spring going. The normal rainfall for the entire month of June is 87mm in Montreal, so we are on track for another wet month.

D-Day - the most important weather forecast in history

Canadian troops on Juno Beach, June 6, 1944. (Canadian War Museum)

An accurate weather forecast was vital to the success of the mission to liberate Europe. This would be the most important forecast ever delivered.

READ ALL ABOUT IT HERE: The 75th Anniversary of the Allied invasion of the Normandy coast.

Strong thunderstorms and tornado strike Ottawa Valley

Photo via the Twitter feed of the Ottawa Paramedics (@Ottawa_9_1_1)

Strong thunderstorms are moving across eastern Ontario and western Quebec late Sunday afternoon and evening. The storms should dissipate by midnight as the front moves east.

The tornado above, formed just before 6pm near Cumberland, Ontario. The storm moved along the Ottawa River before moving into western Quebec. Damage has been reported in several regions including Orleans where trees are down and roofs torn from homes.