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.