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.