Elevated risk for strong thunderstorms for Montreal

Storm damage from a potential tornado in Saint-Adolphe-d'Howard Saturday afternoon. The strong thunderstorm moved across the Ottawa Valley and into the lower Laurentians during the late afternoon. (Photo via Twitter @QuebecVortex)

Heat warning in effect for southern Quebec.

The heat and humidity continue across southern Quebec on Sunday, with temperatures expected to climb to 30C (86F) once again. Humidex temperatures will feel like 35 to 40C before the clouds arrive. The weather never really cooled down overnight, remaining warm and muggy, with lows only around 23C (73F). We reached 31C (88F) on Saturday, before clouds and isolated storms arrived. Most of the severe weather remained well north of Montreal moving across the Laurentians into the Quebec City region. As with Friday afternoons storms, damage and power outages were reported.

Hail fell in and around Ottawa. A tornado may have touched down in Saint-Adolphe-d'Howard in the late afternoon, with numerous trees down and serious damage reported to several cottages. Environment Canada will investigate to determine if it was a tornado. Thankfully no injuries were reported during this busy vacation period.

This brings us to Sunday and the renewed threat for severe weather. Clouds will increase today ahead of a cold front. Pre-frontal showers and thunderstorms are expected by mid-afternoon, some severe. The threat initially will be for strong winds and hail. However as we head into the evening hours, heavy rain and the risk for flash flooding will take over. The front is expected to move slowly, only clearing the region by Monday morning. Storms may be slow moving, with the threat for prolonged heavy rain in any one area. A good 25mm (1 inch) is expected in Montreal, but more may fall where storms occur.

If you have any outdoor plans today, pay close attention to the weather and listen for a weather watch or warning that may be issued.

Skies will be partly cloudy Monday, with yet another chance for isolated showers and thunderstorms. The weather will final calm down for Tuesday, with sunny skies, lower humidity, and a high of 26C (79F).

Temperatures soar on both sides of the Atlantic as the UK records warmest day ever

Searing heat has created ideal conditions for raging wildfires in many parts of Spain, England and France. On Tuesday, the London Fire Brigade had its busiest day since World War II, responding to over 2600 calls. Meanwhile in the Gironde Region of southwestern France (shown above), fires forced thousands of residents to flee as firefighters worked around the clock to try and control the rapidly spreading wildfires and save as many homes as possible. Photo courtesy SDIS 33 Firefighters 

Heat Warning posted for metro Montreal, southern Quebec, eastern Ontario, northern New York and Vermont.

These truly are the dog days of summer as heat and humidity stretch across the United States and into central and eastern Canada. On Tuesday, highs reached into the low 30s across many regions of southern Ontario and Quebec, officially just shy of 30C at Trudeau Airport. When you factor in the humidity, temperatures felt closer to 40C. More of the same weather can be expected on Wednesday, before a strong cold front produces thunderstorms on Thursday. A heat warning remains in affect for a large portion of the region including all of southern Ontario and Quebec as well as portions of upstate New York and New England. Highs on Wednesday will reach into the 30s for many of us.

The heat is surging across the southern and central US, putting a strain on the power grid and dwindling water supplies. Temperatures were in the middle 40s across Texas and Oklahoma on Tuesday, with upper 30s across Louisiana and across the deep south. The heat is spreading north into the Middle Atlantic and Northeast. 

European Heatwave

Meanwhile the heat has broken slightly in the United Kingdom after they recorded the warmest temperature on record Tuesday. The high reached 40.3C (104.5F) in several locations, surpassing the previous high of 38.7C set only in 2019. London's Heathrow Airport reached 40C, just one of several communities that broke the record. The dry, hot weather generated numerous grass fires that destroyed dozens of homes. The London Fire Brigade had its busiest day since World War II, responding to over 2600 calls for service. The department averages 300 to 500 calls per day under normal conditions. Hundreds of dwellings were destroyed.

The heat also surged across Spain, Portugal, Italy and France. Temperatures were as warm as 45C. Fires are raging across France, especially in the hard-hit Gironde Region, where thousands have been forced to evacuate.

Thousands have died due to heat related illnesses. Only 1 percent of the population in the UK has access to air conditioning. Weather conditions such as those experienced over the last few days are extremely rare in England and the UK. Temperatures are expected to cool down to more normal levels, with highs in the upper 20s Wednesday and lower 20s for the balance of the week. Much needed rain is forecast as well.

Much needed rain followed by more heat and humidity

Large crowds turned out for the annual car show held Sunday at Point-du-Moulin Historical Park on Île Perrot. The weather was perfect along the Lac-St-Louis shoreline, with a nice breeze providing relief from the 30C heat and humidity. (ValleyWeather Photo)

Some much needed rain is moving along the 401 Monday morning and should arrive in Montreal by mid-afternoon. A warm front will lift across the region today, accompanied by some tropical rains. parts of southern Ontario received as much as 70mm overnight, so the system has a history of moderate precipitation. As of 10am this morning, heavy rainfall warnings have been issued for the St Lawrence Valley of Ontario from Kingston to the Quebec border. Expect 25-50mm of rain for those locations and perhaps up to 25mm in Montreal.

The warm front will lift north of Montreal overnight, with more showers and perhaps a thunderstorm possible. The showers will taper off early Tuesday leaving us well established in the warm sector. Expect a very warm, breezy day, with high humidity values. The high will be 28C (83F) Tuesday and up to 31C (88F) Wednesday. Humidex values will rise into the upper 30s, the weather will definitely feel oppressive at times.

More showers and thunderstorms are forecast Wednesday night into Thursday, before skies clear out and humidity levels drop somewhat.

We do need the rain in Montreal, as July has been rather dry to date. Only 18.4mm of rain has fallen through the first half of the month, most of that in a few hours on July 12.

The weekend weather in Montreal was absolutely spectacular, with sunshine and warm temperatures. We surpassed 30C (30.6C) on Sunday at Trudeau Airport, the first such reading this July. Other locations around southern Quebec were even warmer, with 31.3 (89F) at Saint-Anicet and 32.2C (90F) on Ile Perrot.

Speaking of heat, the central portion of the US has been baking this July, and that heat moved into southern Saskatchewan on Sunday. Val-Marie reached 39.2C (102.5F). The heat is moving east into Manitoba and northwest Ontario Monday.

European Heatwave

North America is nor the only place recording searing heat, an unprecedented heatwave is impacting portions of western Europe. Spain, Portugal, France and England have all been experiencing record-breaking heat. Lousa in central Portugal hit 46.3C (115F) last Wednesday. The heat has lasted nearly a week, with the death toll rising over to over one thousand across Europe. Numerous forest fires are burning as well in the hot, dry weather. Italy has declared a state of emergency across most of the northern region. Water use is being limited to food preparation, domestic use and healthcare. Parts of the U.K. are expecting their warmest days in history on Monday and Tuesday.

Hot and humid weather returns to Montreal this weekend

Tuesday afternoons strong thunderstorms produced brief heavy rain in Montreal, but most of the severe weather and damage occurred south of the city. The photo above was taken as the storms moved through Saint-Laurent around 2pm. (ValleyWeather Photo)

Typical July weather can be expected during the upcoming weekend in Montreal, as a southwesterly flow of warm, moist air develops over southern Quebec. This will pull in some of the heat that has been building across the central portion of the United States since the start of the month.

Before then, an upper air disturbance will move across the St. Lawrence Valley Thursday, accompanied by some pop-up showers and isolated thunderstorms. We are not expecting any severe weather, with the only threat being some heavier but brief downpours. The day will be a touch muggy, with highs around 24C (76F). On Friday, skies should clear, setting the stage for a rather warm weekend. Expect mostly sunny skies Friday, Saturday and Sunday, with highs ranging from 27C (81F) Friday up to and over 30C (86F) over the weekend. Overnight lows will be very warm through next week, ranging from 19 to 22C (66-72F). We are expecting the warm and humid weather to persist into the early part of next week at the very least along with an increase in thunderstorm activity.

The strong thunderstorms that impacted southern Quebec on Tuesday afternoon largely missed the island of Montreal once again. We had some gusty winds and brief heavy rain, but the bulk of the severe weather occurred southeast of Montreal across the South Shore and Eastern Townships. There were reports of tress and power-lines toppled near Saint-Jude, as well as Hatley and Lac-Brome. A portion of Highway 143 was closed after being blocked by fallen trees and power poles. 

Speaking of severe weather, the Northern Tornadoes Project out of Western University has confirmed the first tornado of the year in Quebec, near Val-des-Lacs on July 1st. The storm was estimated to be an EF-1, with maximum winds at 145km/h. They also observed microburst damage near Riviere-Rouge, Quebec. No injuries were reported, but there was widespread tree damage observed.

Thursday marks the 35th anniversary of the Decarie Expressway flood. A series of very strong thunderstorms crossed the city of Montreal on July 14, 1987, dumping over 100mm of rain in less than 90 minutes. You can read the entire story HERE. 

Another stretch of perfect summer weather for Montreal

One good thing about having a pup that loves to get up at the crack of dawn, is I get to see the sun rise during the summer months. This week has been spectacular, with warm sunny days, and cool nights. (ValleyWeather Photo)

High pressure will dominate the weather across southern Quebec into early next week. The only exception will be this evening, as a weak frontal boundary crosses the region. There may be an isolated shower or sprinkle around, scattered clouds and a wind shift but little else. Most regions will remain dry. On Friday, sunshine returns, with light winds and low humidity.

The weekend at this time looks spectacular, with wall to wall sunshine, cool nights and seasonably warm days. Temperatures in Montreal will range through the middle 20s (70s F) for daytime highs, with overnight lows in the low to middle teens. Ile Perrot dropped to 14C (56F) Thursday morning, close to the normal low of 15C (59F).

The hot and humid weather will remain across the central and southeast portion of the US where temperatures are in the high 30s and humidex readings into the 40s. Some of that warm weather may begin to shift northward next week, along with the risk of showers and thunderstorms by Tuesday. Until then enjoy the near-prefect summer weather.

June ended on a very wet note across southern Quebec, with many locations reporting well-above normal rainfall. Montreal recorded it's second wettest June, with 169mm of rain falling at Trudeau Airport. That amount placed June 2022 a distant second to the 215mm that fell in June 1943. I measured  175.1mm here on Ile Perrot, including 85.4mm over just 48 hours on June 22 and 23.

Arctic Heatwave

The hot weather in Canada s far this month has been occurring in an unusual location, across the far north. Portions of  both the Yukon and Nunavut have been under heat warnings. Temperatures have risen into the high 20s and low 30s. Inuvik, located at 68.3N a full 200 km within the Arctic Circle, rose over 30C on three consecutive days for the first time since weather records have been kept. That dates back to 1957. The high on July 2 was 30.6C, July 3, 30.7C and July 4, a scorching 31.8C (89F). The high today is expected to reach 31C, with the heatwave lasting into early next week.

Warm & humid Canada Day forecast for Montreal

Happy Canada Day!

Another long weekend is upon us, with an extended period of summery weather expected. Warm and humid air will stream into southern Quebec on Thursday and Friday, with temperatures approaching 30C on Canada Day. Humidex values will be in the middle 30s despite expected cloud cover on Friday. Thursday so far has been a touch cooler than expected as stubborn clouds have prevailed most of the day. We should see some breaks overnight and into Friday morning.

Winds will increase as well on Friday, out of the southwest 30 to 50km/h, drawing in the warm and sticky airmass from the southern US. A few showers and isolated thunderstorm are possible late Friday along a frontal boundary before sunshine returns on Saturday. We can then expect a stretch of ideal summer weather as high pressure builds into southern Quebec. Expect seasonable weather, with high temperatures in the upper 20s and lows in the teens. Sunshine is forecast into at least Tuesday of next week.

Showers and thunderstorms move into Montreal on Wednesday afternoon. June has been a very wet month across southern Quebec, with 170mm of rain falling at Trudeau Airport.

We can certainly use a break from the wet weather, with nearly 170mm of rain falling at Trudeau Airport during the month of June. The long-term normal for the month is 87mm. I have measured 175.2mm of rain at my home on Ile Perrot since June 1st.

Be safe and enjoy the Canada Day and July 4th long holiday weekend.

Slow moving showers and thunderstorms for Montreal

With nearly 25mm of rain in the last 24 hours, a heavy rainfall warning has been issued for most of southern Quebec. A very moist airmass is in place, with slow moving showers and thunderstorms forecast to develop along a frontal boundary this evening and into the overnight period. Some flooding is possible. The front should drift to our east on Thursday, with precipitation diminishing.

Heavy Rainfall Warning posted for southern Quebec. Severe thunderstorm watch for eastern Ontario and west Quebec.

A stationary front over southern Quebec will become the focus for slow moving showers and thunderstorms this evening and into the overnight period. Showers and thunderstorms early Wednesday morning have moved well southeast of Montreal after close to 25mm of rain fell over the last 24 hours. Montreal is now in the warm sector, with temperatures in the middle 20s and dew points climbing into the upper teens.

The moist airmass will set the stage for very wet, slow moving showers and thunderstorms across the St. Lawrence Valley. Amounts in the 30 to 50mm range will be possible this evening and overnight, and may even reach 70mm locally in the slowest moving storms. The storms will moving be moving from north to south across southern Quebec.

The ground is quite saturated at this point, so there is a risk of some isolated flooding and ponding of water in places. Precipitation for the month of June is now above normal in Montreal, with 91.6 mm falling at Trudeau Airport to date, with even more in other parts of the city. 

Temperatures will be mild, with overnight lows in the upper teens and daytime highs Thursday in the lower 20s. The warm and humid airmass present across the US Midwest and Ontario will become fully established in Montreal on Friday into the upcoming weekend, with daytime highs in the upper 20s and lower 30s.

Strong thunderstorms cause flooding & damage in Montreal

Just one of several roads that were closed across the Montreal region on Thursday afternoon as a result of several rounds of strong thunderstorms. (CBC)

A series of strong thunderstorms swept across southern Quebec on Thursday afternoon as a cold front sliced into a warm, muggy and highly volatile air mass. The result was cell after cell of powerful thunderstorms, some of which generated isolated tornadoes. In Montreal, the storms arrived around 4pm, moving southeast across the city through 7pm. The airport reported thunder and lightning for four consecutive hours, an extremely rare even for Montreal.

A lightning strike ignited a fire that destroyed two homes and damaged a third in Saint-Marthe-sur-le-Lac northwest of Montreal. (CTV)

The end result was 40 to 60mm of rain in a short period of time, creating flooding on several highways and a nightmare commute home for many. Several underpasses were closed after vehicles became disabled in rising flood water. The storm produced large hail in swath from Hawkesbury, Ontario into Lachute and Two Mountains north of Montreal. Smaller hail of less than 2cm in diameter was reported within the city.

A lightning strike just after 4pm ignited a fire that destroyed two homes and damaged a third in the off-island north shore community of Saint-Marthe-sur-le-Lac. It took firefighters from 5 municipalities to bring the blaze under control by 9pm. No injuries were reported. Hydro-Québec reported outages to almost 43,000 customers during the evening hours, but that number it down to just over 6700 Friday morning.

Day turned to night a severe thunderstorms crossed the Ottawa River to begin their assault on the Island of Montreal just after 4pm on Thursday. (ValleyWeather Photo)

Several regions of Quebec were under tornado watches and warnings Thursday afternoon, but no official reports are in as of my writing.  I did observe plenty of rotating clouds from my vantage point on Ile Perrot. I measured 30mm of rainfall, the bulk falling between 5-6:30pm. Trudeau Airport measured 39.6mm of rain, with 62mm at St Hubert Airport on the south shore.

The severe weather also impacted parts of eastern Ontario, with major damage reported in Bellville, Ontario where winds gusted to 106km/h. Several roofs were damaged along with downed trees and power lines. Western University's Northern Tornadoes Project will be investigating the damage today to determine if tornadoes occurred during the storm.

In the wake of the storms, Friday will be partly cloudy with scattered showers and isolated thunderstorms this afternoon. The strongest of the storms today be southeast of Montreal. The high will be 25C (77F). Behind a secondary cold front today, much cooler air will pour into the region. Saturday will be cloudy, with showers and unseasonably cool, with a high of only 14C (56F) forecast.

The good news is that Sunday will be sunny with near-perfect weather for the Canadian Grand Prix. Expect dry conditions and a high of 21C (70F).

Strong thunderstorms Thursday - much cooler weekend ahead

A cold front will produce widespread shower and thunderstorm activity across eastern Ontario and southern Quebec on Thursday. Some of the storms may be on the strong side, especially across eastern Ontario, with heavy rain, hail and high winds possible. There is even a risk of an isolated tornado in Ontario.

Active weather continues across many regions of Canada this week, perhaps with the exception of southern Quebec, at least for now. Cloud cover from a decaying area of thunderstorms in Ontario, is limiting the sunshine across southern Quebec Wednesday morning. Montreal is muggy and on the warm side, but not as warm as expected due to the cloud cover. Expect some breaks this afternoon, with an optimistic high of 27C (81F). Tonight will be muggy, with lows remaining in the upper teens to near 20C. Thursday will see a high once again of 27C.

A steamy airmass is located across the midwestern US Wednesday, nudging into southwestern Ontario. Widespread heat warnings are posted today, including across extreme southwestern Ontario where temperatures are expected to soar into the middle 30s, with humidex readings over 40C. This same airmass was the trigger for widespread severe thunderstorms late Monday and Tuesday. The storms produced wild lightning, strong wind gusts in excess of 120km/h and hail. Power outages and damage was observed from Michigan into portions of Ontario and south across Indiana and Ohio.

On Thursday, warm and humid air will settle across eastern Ontario and southern Quebec. By mid-afternoon, strong thunderstorms are forecast to develop along a potent cold front in central Ontario, moving southeast into the St. Lawrence Valley. At this time, the bulk of the storms should remain southwest of Montreal, clipping the Valleyfield area in the afternoon. A few isolated cells may make it into the metro region. Heavy rain, strong wind gusts and hail will be the main threat. I will update the potential for severe weather in Montreal early Thursday morning.

A childhood friend of mine sent this photo of heavy wet snow, taken Tuesday, June 14 in Elk Valley, BC. The snow fell from a strong storm system moving east across Montana and into Alberta and Saskatchewan. The storm produced heavy rain and snow, with flooding reported in parts of Alberta south into Montana and Wyoming.
Photo: Elizabeth Jones

While warm weather prevails in the east, a strong winter-like storm moved across western Canada. Strong winds occurred across southern Alberta and Saskatchewan, along with extremely heavy rainfall and in some cases heavy wet snow. Calgary reported over 50mm of rain, with localized amounts exceeding 100mm. Heavy rain and flooding also impacted parts of Saskatchewan, with as much as 100mm falling in the Battlefords. A childhood friend of mine living in the Elk Valley in southeastern British Columbia sent me a picture of heavy snowfall which fell late Monday into Tuesday morning. The storm in question is weakening across the Prairies on Wednesday.

Temperature and humidity on the rise this week for Montreal

Saturday was a spectacular day for any activity along the shoreline or on the waters of Lac St. Louis. Conditions were calm, humidity levels low and the air temperature was a perfect 25C. More spectacular weather is forecast through Wednesday before showers and storms arrive Thursday.

The weekend turned out much nicer than I had anticipated, especially Saturday. Shower and thunderstorm activity held off for most of the Montreal region, remaining to our west across Ontario. The day was spectacular with low humidity and a near-perfect high temperature of 25C (77F). A few showers finally moved into southern Quebec Sunday afternoon, again largely missing the Montreal region, with no rainfall reported at Trudeau Airport, and only 2.5mm at my home on Ile Perrot.

Trudeau Airport has measured 32.8mm of rain so far in June, with more in locations around the city. The normal is 87mm for the month. Ottawa has already recorded 73.5mm through June 12.

There definitely was an increase in humidity levels on Sunday, and that trend will continue this week, especially by Thursday. High pressure will settle across southern Quebec on Monday, with fair skies and decent temperatures, the high will be 24C (76F). Clear skies Monday night will allow for cooler temperatures, with lows in the lower teens. There may be some patchy for around early Tuesday morning, especially across off-island locations.

Fair weather will prevail through Wednesday, and as the week progresses, temperatures and humidity levels will be on the rise in Montreal.

A dome of dangerously hot air will settle across most of the central US this week, with temperatures soaring into the middle to upper 30s and heat index values into the 40s. Widespread weather warnings are currently in effect for a dangerous heatwave, with hot temperatures expected from the Mexican border all the way to southwestern Ontario. Montreal will remain on the extreme northeastern edge of that heat dome, with temperatures approaching 30C (86F) in parts of the region by Thursday, along with elevated humidity. The heat will be short-lived for Montreal, as a potent cold front will cross the St. Lawrence Valley late Thursday followed by much cooler weather Friday and Saturday.

During the transition to cooler air on Thursday, there will be a chance for showers and a few strong thunderstorms. Until then, enjoy the spectacular mid-June weather.

While storms have largely missed the Montreal region this summer, other parts of the country have been hammered by violent weather. A severe thunderstorms Saturday afternoon produced flooding and damage near Shawinigan. Winds gusted to 72k,/h along with 32.6mm of rain and hail 1-2 centimetres in diameter.

Strong thunderstorms last Thursday and Friday across southern Saskatchewan and Manitoba, produced torrential rain and heavy hail. The hail covered the ground east of Regina.

Strong thunderstorms last Thursday produced a heavy accumulation of hail along the Trans Canada Highway east of Regina. The hail caused damage and several accidents. (Photo - Regina Fire Department)

Unsettled wet weather week ahead for Montreal

Unsettled, wet weather is expected in Montreal for most of the upcoming week.

A series of frontal systems will provide southern Quebec with a rather cloudy, wet week. The first system is on our doorstep Tuesday morning, as low pressure and a trailing cold front move across Ontario and Quebec. Light showers are already occurring in Montreal, with coverage and intensity of the precipitation rather light. We will have a few breaks in the cloud through midday, allowing the atmosphere to destabilize somewhat. Winds will begin to increase out of the southwest ahead of the cold front this afternoon, up to 50km/h, along with the increased risk of showers and perhaps a rumble or two of thunder. Showers will continue overnight. Rainfall amounts by Wednesday morning will be in the 15 to 20mm range for Montreal, with up to 50mm possible across eastern Ontario.

Wednesday though Friday will be rather unsettled, with more clouds than sun and the risk of showers all three days. Our rain chances unfortunately will only increase this weekend, as another low pressure system will approach Quebec from the Ohio Valley. Temperatures will be close to seasonable, with highs in the low 20s and overnight lows in the middle teens.

Meteorological summer has started off rather cool in Montreal, after a hot May. The average high through June 6 has been 22.1C (71.8F), very close the the normal of 22.3C (72.1F). It has been dry so far, with only 2mm of rain, following what was a drier-than-normal May, with 58mm of rain compared to the normal of 81mm. Most of that fell in less than an hour during one thunderstorm on May 16.

Our May heatwave was one for the record books in Montreal. The May 12 to 14 heatwave featured three consecutive record highs, and was the earliest such period on record for the city. The previous "earliest" heatwave was May 27 to 30, 1978. The four daily highs over 30C tied a record set in both 1977 and 1978.

Despite the cooler, wet weather break anticipated this week, it is still looking like a rather hot and humid summer for Montreal.

A high water rescue vehicle evacuates residents from a Miami suburb last Saturday morning after 275mm of rain fell from what would become tropical storm Alex. (Photo: Miami-Dade Fire Rescue)

The Atlantic hurricane season got off to an early start, with tropical storm Alex forming east of Florida this past weekend. The system developed from the remains of Hurricane Agatha that had moved inland over central Mexico last week before crossing into the Gulf of Mexico and reforming as Alex. Alex dumped copious amounts of rain on south Florida over the weekend, producing flash flooding. As much as 275mm of rain fell on Miami Friday and Saturday. The storm then brushed Bermuda before dissipating in the open water of the Atlantic. This is likely just the beginning of what promises to be a busy season according to forecasters at the National Hurricane Centre.

The value of weather warnings and the Alert Ready system

Severe wind damage occurred from Saturday's series of thunderstorms. This church in Sarsfield, Ontario lost its steeple during the hurricane force winds. Nearly one million customers lost power in Ontario and Quebec. Sadly 10 fatalities occurred along with several injuries. The use of the Alert Ready Emergency Alert System likely saved lives. (CBC News) 

Weather warnings save lives, period. There is no disputing this fact. That being said, many I have spoken with or received comments from were upset about the use of the Alert Ready Emergency Alert System this past Saturday to deliver the messages repeatedly to phones, television and radio. This was the first time that Environment and Climate Change Canada used the Alert Ready system for a thunderstorm. Don't blame the system, it worked perfectly and likely saved residents from additional deaths and injuries from the strongest derecho to impact any region of Canada in over 20 years. Unfortunately this particular storm still claimed 10 lives.

A derecho is a long-lived, fast-moving cluster of thunderstorms that generates widespread wind damage. This particular derecho developed over Michigan early Saturday morning and moved rapidly northeast across Ontario and Quebec gaining strength. It impacted an area nearly 1000km long by as much as 100km wide. Embedded within the derecho were isolated tornadoes, one of which hit Uxbridge, Ontario with estimated wind gusts of up to 195km/h, an EF-2 storm. Other potential tornadoes are being investigated including damage near Rawdon, Quebec.

Many other regions received winds of between 100 and 150km/h, including Ottawa. By now, we all know the end result: over 1 million residents were left without power and widespread damage occurred to cars, homes, businesses, power poles and trees, lots of trees. Many of those trees fell onto cars, homes and people. A majority of the deaths were blamed on falling trees. This is why it was so critical to have the warnings put out in advance of the storm system, and have them repeated as often as possible. This was a very serious weather event.

The challenge of weather warnings is that not every area will be hit the same. Often some neighbourhoods or regions are spared completely. Such was the case on Saturday for most of Montreal, as the worst of the storms travelled just north of the metropolitan region. If it missed your home, be grateful. I would rather life be put on hold for 30 or 45 minutes by a weather warning that does not materialize, than be caught outside in such dangerous conditions. Many who were caught outside Saturday paid a steep price.

Many vehicles were destroyed from the fierce winds. (CBC)

I wrote in my blog early Saturday morning about the dangerous weather day I was anticipating. By 10am, a severe thunderstorm watch was in effect for Montreal. A weather watch (tornado or thunderstorm) simply means that conditions are favourable for severe or dangerous weather to develop, but none has at that point. Remain vigilant, weather watches often cover a large geographical area. A severe thunderstorm warning is much more specific, and often narrows the region down and details where the storms are and more importantly, where they are going. Understand the difference between the two, because it is very important. The watch does not mean you are about to be hit, the warning on the other hand increases the risk significantly.

Thunderstorms are very local weather events and often develop and dissipate quickly. That is why warnings don't always deliver. They are still very valuable tools for meteorologists and the public in general, and should not be taken lightly. Severe weather events in southern Canada are on the rise. You can almost certainly expect more severe thunderstorms as the summer moves along.

Download your favourite weather app and subscribe to push notifications. If you have any outdoor plans on days when storms are forecast, pay attention to the changing weather and seek shelter when storms approach or a warning is issued. Have fun this summer, but stay safe.

Deadly thunderstorms race across Quebec and Ontario

Deadly thunderstorms swept across Ontario and Quebec Saturday afternoon. Nearly 1 million were left without power in both provinces, with 5 fatalities in Ontario. The photo above is the Paroisse Saint-Hugues in Sarsfield, Ontario, just east of Ottawa. (CTV News)

Nearly one million residents of Ontario and Quebec were left without power Saturday afternoon after strong thunderstorms swept across both provinces. As of 4pm Sunday, there is still 316,000 Hydro-Québec customers in the dark. Hydro has assigned nearly 1000 workers to tackle the monumental cleanup and restoration. The same is true on the Ontario side of the border.

Widespread damage was also reported across the Laurentians north of Montreal. Hundreds of thousands remain without power on Sunday. Photo: Ledy Quintero

Photo: Ledy Quintero

A strong line of thunderstorms swept east across Ontario and the Ottawa Valley and into southern Quebec Saturday afternoon. The storms were fierce, with gusts of wind over 100k/h at many locations. Several supercell thunderstorms produced hail 2 to 4cm in diameter, along with heavy rain and strong winds. A peak wind gust to 132km/h was observed at Kitchener, Ontario, with 120km/h in Ottawa. In Quebec, the strongest wind was at Lac Memphremagog at 144km/h, with 100km/h at Quebec City and 70km/h in Montreal. Before the storms Montreal reached a sweltering 31.5C (89F), tying the record set just one year ago. Humidex values were near 40C.

The wind caused severe structural damage in and around the Ottawa Valley, destroying several buildings and tearing down hundreds of trees and power lines. There were sadly 5 fatalities reported in Ontario as a result of the storms.

In Quebec, the Laurentians and Lanaudiere were the hardest hit regions, with numerous reports of damage and widespread power outages.

The Montreal region was even under a tornado watch Saturday afternoon, but the worst of the storms passed north of Montreal.

A reader commented as to why I posted a picture of the Gaylord, Michigan tornado with my Saturday morning column. As stated in the cutline with that photo, it was to drive home the point of the level of concern I had with yesterday's severe weather potential. Unfortunately that concern was validated. Severe weather season is upon us and more storms will follow as we head into the warmest month of the year in Montreal.

Much cooler weather has returned to Montreal late Sunday behind another cold front. Just a few showers are possible, before skies clear out into Victoria Day Monday. The low will be a chilly 8C (48F), followed by a high of 19C (66F) on Monday.

At left: Many power poles were snapped in half by the ferocious winds. (Photo Ledy Quintero)

Steamy stormy Victoria Day weekend for many in Ontario and Quebec

A rare tornado swept across the northern Michigan town of Gaylord on Friday. The storm resulted in one fatality and several injuries. Damage was widespread. The threat for strong thunderstorms and isolated tornadoes will stretch from central Ontario into western Quebec on Saturday.

A Severe Thunderstorm Watch in effect for metro Montreal through Saturday. Large hail, gusty winds, heavy rain, dangerous lighting and even an isolated tornado are possible with any storms through sunset.

A sultry, steamy airmass is trying to move into southern Ontario and Quebec early Saturday morning. As of 9 am, the temperature is already 25C (7F) on Ile Perrot, with elevated humidity levels. Expect highs to reach near 30C (86F). Early Saturday morning, a frontal boundary stretched from Michigan and the upper Midwest into Quebec. Along it, thunderstorms have been developing, some severe, with hail and heavy rain.

 This front has a history of very strong thunderstorms. In the northern Michigan town of Gaylord, a strong thunderstorm produced a tornado on Friday resulting in one fatality and several injuries. Damage and power outages were widespread. The severe weather threat will persist in Montreal most of Saturday and again during a few hours on Sunday afternoon as a strong cold front sweeps the region. In between the showers and storms, the weather will be hazy, misty and muggy.

Similar weather can be expected across southern Ontario, and into New York and New England. Heat advisories have been issued for a portion of Vermont and parts of New England, where the combination of high temperatures and humidity will push heat index values into the middle 30s (90s).

Once the front moves east of the region late Sunday, we can expect clearing skies and sharply colder temperatures. Monday will be sunny, with highs only in the middle teens.

SPRING SNOWSTORM

You read that correctly, while eastern North America bakes, a late spring snowstorm swept across portions of the southern Rockies. Denver went from a high temperature of 31C (88F) on Thursday to 15cm of heavy wet snow by late Friday. Early Saturday morning, the temperature was 1C (34F), with light snow falling in Denver. Snowfall amounts of 15 to 60cm fell across portions of the central Rockies. Widespread tree damage and power outages have been reported.

Strong thunderstorms cooler weather on tap for Montreal

Dense fog early Monday morning across the Montreal region, should burn off leading to a warm and muggy day, with strong thunderstorms expected by late afternoon. (ValleyWeather Photo)

Dense fog to start the day followed by the threat for strong to severe thunderstorms for metro Montreal.

As of 6am, visibility was down to 0.2km at Trudeau Airport in the fog, so drive safely.

Our early taste of summer will come to an end briefly over the next 24 as a strong cold front and upper level low move into southern Quebec later Monday. Sunday was another unseasonably warm and muggy day, with highs reaching 24C (76F) in Montreal. This after three consecutive days of record-breaking  highs in the low 30s. There were numerous scattered thunderstorms and downpours across Ontario and Quebec, but most missed my location here on Ile Perot, with only 1.5mm of rain falling, with 0.4mm at Trudeau Airport.

We have one more muggy, warm and humid day before a change in the airmass occurs. Monday morning dawns misty and foggy for many after the overnight full lunar eclipse, for those who were lucky enough to view the celestial event. We should have a few hours of sunshine after the fog burns off and before the clouds increase around noon. Temperatures should quickly rise into the middle 20s. A broken line of thunderstorms is expected to develop across upstate New York and eastern Ontario and move east into southwestern Quebec by 3pm. Some of the storms may be strong, with heavy rain, hail, frequent lightning and gusty winds the main threat. A severe thunderstorm watch may be needed for a portion of our area.

The weather will become rainy tonight as the upper level low swings into southern Quebec. Winds will increase out of the northwest up to 70km/h and temperatures will turn noticeably cooler, with a low of 12C (54F). The high on Tuesday under showery, blustery conditions, will only be 15C (59F). The upper level low will gradually move northeast out of our region by Wednesday, with clearing skies and moderating temperatures.

We have had a very dry month to date, with only 7.6mm of rain falling in Montreal. That should change over the next 24 hours, with the potential for 25 to 50mm (1-2 inches) of rain between thunderstorms and post-frontal showers.

Be safe today, if you have any outdoor activities planned, be aware of thunderstorm development.

Record-breaking warmth ahead for southern Quebec

High pressure is forecast to dominate the weather in Montreal into the upcoming weekend, with warm and dry weather expected. Temperatures will rise through the 20's into the low 30s for some locations by Friday. Expect records to fall in Montreal on Thursday and Friday. The dry, warm weather has also increased the risk of brush and forest fires in the province. Open air burning, including campfires, is not permitted across southern Quebec at this time.

Open air burning prohibited across southern Quebec

Only 5mm of rain has fallen in Montreal so far this month, a far cry from the wet April we experienced. The lack of moisture, combined with low relative humidity levels and gusty winds at times has resulted in an open fire ban across all of southern Quebec. The ban has been put in place by SOPFEU, the agency that oversees fire fighting and prevention in Quebec forests. Most local municipalities are requiring permits for any outdoor burning, this includes campfires and backyard fire pits. The risk is just too great, as we have dry conditions and plenty of fuel from dead leaves and grass from the winter. The ban also extends into portions of Ontario and New York. Already this past Sunday, a brush fire occurred at the Club de Golf de L'Ile in RDP, resulting in three alarms, requiring 85 firefighters to bring under control. There are currently 12 active fires in Québec. Since the start of the protection season, 138 forest fires have impacted 114.2 hectares. The average over the last 10 years at this time of the year is 102 fires over an area of 82.4 hectares.

Map courtesy SOPFEU Quebec, showing the locations in southern Quebec where open fires are prohibited at this time.

SOPFEU is asking all residents to assist in making sure that the ban on open fires in the forest is respected. This measure is intended to limit the risk of forest fires. Any person who contravenes the order prohibiting open fires in or near forests is liable to a fine as well as the costs incurred to fight the fire according to the Ministry.

Temperatures are on the rise as strong high pressure centred over southern Quebec dominates the weather. It will remain nearly stationary through Saturday, pushing any storms well south of the region. The high on Monday was 24C (76F), and we will gain a degree or two each day into the weekend. By Thursday, highs will be in the upper 20s, with even a few low 30s around. The record high in Montreal for Thursday is 27.4C (81.3F) set in 1992, Friday, 28.5C (83F) also from 1992 and Saturday 29.2C (84.5F) set in 2004. We have a decent shot at the records for both Thursday and Friday. The normal high/low for early May in Montreal, is 19C (66F) and 7C (45F).

Late Saturday moisture will begin to increase across the region as a cold front approaches from western Canada. There will be a risk of showers and thunderstorms as we head into Sunday, along with more seasonable temperatures.

Wet and cold April in Montreal ends on sunny note

More images of April snow, as an upper level low produced rain and snow on Wednesday. By Thursday morning, some locations in the Eastern Townships and Beauce region had measured several centimetres of wet snow. The photo above is from Oxford County, Maine, just southeast of the Sherbrooke area, taken Thursday morning. (Maine DOT)

I had to wonder where spring was as I walked my puppy early Friday morning, wearing my winter coat, hat a gloves on April 29. The temperature was just shy of the freezing point in the pre-dawn hours across many off-island locations. The cool weather will persist today, a trend we have observed during the entire month of April with just a few exceptions.

The average temperature in Montreal for April sits at 10.6C (51F) a full degree below normal. It has been a wet and at times white month, with 20.2cm of snow and 114.4mm of rainfall, both well-above the normals of 12.9cm and 67.7mm respectively. As recently as Wednesday, wet snow fell across portions of southern Quebec, including the Montreal region. Several centimetres accumulated across southeastern Quebec along the New England border.

The good news is that we are in for a beautiful stretch of sunny weather to end April and start May. High pressure will crest over southern Quebec, with diminishing winds and seasonable highs. This weekend will feature wall to wall sunshine, with moderating temperatures. Friday will be cool and breezy, reaching only 12C (54F), but highs should reach 14C (56F) Saturday, 17C (63F) Sunday and close to 20C (68F) on Monday. No rain is forecast through the early portion of next week.

Beyond that, May looks to be relatively normal in the temperature department, which means a slow but gradual warming trend for daytime highs through the teens and into the low 20's by the end of the month. Overnight lows warm from a degree or two above freezing to 10C (50F) by June 1st.

Record-breaking snowfall briefly interrupts spring in Montreal

Heavy wet snow accumulated rapidly in Montreal early Wednesday morning, with over 10cm falling in just a few hours. The snow melted away just as quickly as temperatures warmed above freezing in the afternoon. (ValleyWeather Photo)

Spring was put on hold in Montreal for a few hours on Wednesday. The snow came quickly and melted away just as fast. A record-breaking 10cm accumulated in Montreal in just a few hours. It was enough to shatter the daily record of 7.6cm set in 1949. A strong coastal storm moved inland over New England producing heavy precipitation in Montreal. In all 33.8mm of precipitation occurred at Trudeau Airport, with half of that falling as snow, much of it melting on contact. The exception was during a three hour period early Wednesday morning when the 10cm accumulated. This was poorly timed during the morning commute across southern Quebec. During that window, the snow fell heavily, and accumulated quickly reducing visibility to less than a half kilometre and coating area highways.

Dozens of accidents were reported in metro Montreal and off island to the south and west. In addition to the heavy wet snow, winds gusted to 60km/h in Montreal. The wind and weight of the snow knocked power out to nearly 50,000 Hydro-Quebec customers across the southern portion of the province.

By midday, temperatures warmed enough that the snow mixed with rain and began to melt away. By early Thursday morning, only a few patches remained.

The weather will remain cool for April, with daytime highs in the upper single digits and lows near the freezing point into the upcoming weekend. A cold rain is forecast for Thursday, before decent weather on Friday and Saturday. More rain is forecast for Sunday in what has become a very wet April. Already 118.8mm has fallen at Trudeau Airport, well above the long-term average of 82.2mm.

April Nor'Easter to bring rain and snow to southern Quebec

A late season coastal storm will pull enough cold air into the region Monday night to produce wet snow. The heaviest snow will fall north and east of Montreal, but a few slushy centimetres are possible in the St. Lawrence Valley after midnight. (AccuWeather.com)

Rain will mix with snow overnight into Tuesday across the Montreal region, with the possibility of several centimetres accumulation for the city, more to the north and east. I expect most of the snow to remain on colder surfaces, but there may be some slick spots on area roads.

After a rather breezy and chilly Easter weekend, Monday has dawned delightful, with light winds and sunny skies. The temperatures will moderate after early morning lows near the freezing point to a daytime high of 10C (50F) in Montreal.

April can be a tricky weather month across North America as the seasons battle for supremacy. Last week, temperatures soared into the 30s (80-90F) across the eastern US, while in the west, an historic blizzard shut down parts of North Dakota, Saskatchewan and Manitoba. A record-breaking 36 inches (91.4cm) of wind blown snow fell over three days at Minot, North Dakota, shutting down all travel including Interstate 94 and US 2 shown above. (North Dakota Department of Transportation) 

The good weather will not last very long, as two areas of low pressure begin to impact the region. The first will move into southern Ontario later today before weakening. A second low pressure along the US east coast will become the primary storm, moving into southern New England on Tuesday while strengthening. Clouds will increase late in the day today, with precipitation in the form of rain beginning this evening in Montreal. The rain will mix with and change to wet snow overnight. The snow may be heavy at times across some parts of southern Quebec, with a general 5-10cm possible in many locations. In the immediate St. Lawrence Valley, warm surfaces should help to keep accumulations below 5cm. The snow should mix with rain by Tuesday morning before ending in the afternoon.

Winds will be rather brisk on Tuesday, gusting between 30-60km/h. Tuesday will be raw for mid-April, with a high expected of only 3C (38F) for Montreal. Regions northeast of Montreal towards Quebec City and the lower St. Lawrence can expect more snow, with 10-20cm possible.

Heavy wet snow is also forecast across the Adirondacks of northern New York, where as much as 25cm may fall by Wednesday morning. A winter storm warning has been issued for those regions.

Skies will clear out Wednesday in Montreal along with milder daytime temperatures of 9C (48F).

Historic spring blizzard to bring rain and thunderstorms to Montreal

Travel conditions are nearly impossible across North Dakota, with over 800km of Interstate 94 closed across that state. Similar weather can be expected in southern Manitoba on Wednesday. (NDDOT)

A powerful spring blizzard is hammering portions of North Dakota, Montana and neighbouring southeast Saskatchewan and southwest Manitoba early Wednesday morning. The storm promises to be epic, with 25 to 60cm of snow forecast along with 70 to 100km/h winds. Authorities have already closed more than 500 miles of Interstate 94 across North Dakota and Montana.

A strong late-season winter storm will impact portions of southern Manitoba and southeast Saskatchewan with blizzard conditions expected for over 24 hours. Weather conditions are deteriorating early Wednesday morning in Manitoba, with heavy snow and increasing north winds. (AccuWeather)

Forecasters north of the border are expected the same, as the snow and wind ramp up today in Manitoba. Visibility early this morning is already under 1km at Winnipeg and Brandon. Late season storms are not uncommon in this region, however the strength of this particular blizzard is rather impressive. Low pressure will slowly move across the northern plains and into Minnesota and northwest Ontario over the next 48 hours. In addition to the strong winds and heavy snow, bitter cold will push across the southern Prairies. Temperatures early Wednesday morning are already well below freezing and expected to drop into the minus teens by Thursday morning. Strong winds and heavy snow will make travel impossible in western Manitoba. Expect highway closures and possible power outages.

Heavy Rain and Thunderstorms

On the warm side of the storm, an elongated warm front is producing periods of heavy rain and thunderstorms north and east of the center. A strong cold front trailing from the storm is generating severe wether and tornadoes across the central and southern US plains.

As the storm lifts into Ontario, Montreal can expect periods of steady rain to develop along the aforementioned warm front. A soaking 20 to 30mm is possible, which will add to water levels on both the Ottawa and St. Lawrence Rivers. A heavy rainfall warning has been posted for portions of southern Quebec including metro Montreal. No flooding is anticipated at this time, but water levels are being closely monitored. On Thursday, the trailing cold front arrives, accompanied by gusty winds and scattered showers and isolated thunderstorms. Skies will clear out Thursday evening.

Good Friday at this time is shaping up to be the best weather day of the Easter/Passover long weekend for Montreal. Conditions will be sunny and mild, with a high near 15C (59F) in Montreal, warmer south of the city towards the US border. Conditions will be rather breezy, with wind gusts to 50km/h likely. The weekend at this time is going to be dreary and chilly as an upper level low moves east from the Great Lakes. Look for scattered showers both days and perhaps even a few flurries around for Easter Sunday.