August flipped the script with rainfall

August flipped the script with rainfall

We have all the weather data from the main reporting stations across the Prairies, so we can review August weather and then look at the latest three-month forecasts or predictions. Instead of going province by province, I will rank the main reporting sites by mean temperature, how far above or below average it was, total […] Read more

The two main conditions almost always present for extreme rainfall are plenty of moisture and slow movement. | File photo

How atmosphere affects extreme rainfall

In the last column, we discussed several factors that can result in extreme rainfall events. Let’s wrap up this topic by looking at different weather patterns that tend to be associated with these events and consider how changing weather patterns might contribute. Let’s first look at some of the rainfall records across southern and central […] Read more

Several factors must come together for an extreme rainfall event to occur. | File photo

Several factors can contribute to heavy rainfall

Several factors must come together for an extreme rainfall event to occur. Sometimes you need more than one factor and other times, if the factor is strong enough, you just need one. Let’s look at those factors. Atmospheric moisture: For heavy rain, there must be a significant supply of moisture in the atmosphere. When warm, […] Read more


Humidity is the amount of water vapour in the air. The warmer the air, the greater the distance between air molecules and therefore the greater the holding capacity of air for water vapour. Warm air has the capacity to hold much more water than cold air. | Getty Images

Humidity often overlooked but potentially severe

One summer weather event is regularly overlooked but potentially severe: humidity. By its simplest definition, humidity is the amount of water vapour in the air. The warmer the air, the greater the distance between air molecules and therefore the greater the holding capacity of air for water vapour. Warm air has the capacity to hold […] Read more

Although a heat wave is a weather event, its impact on people is key. This is why we can have heat waves in winter, but they don’t get as much attention due to their more limited impact on people. | File photo

That sinking feeling when the heat hits

After a couple of July heat waves, the Prairies have seen a bit of a cool down. Although a heat wave is a weather event, its impact on people is key. This is why we can have heat waves in winter, but they don’t get as much attention due to their more limited impact on […] Read more


After a cool June across the Prairies, July turned things around.  | Getty Images

Will August stay warm?

We are well into the second half of summer and from a climatological perspective, temperatures are statistically starting their decline as we move toward autumn. That doesn’t mean August will be colder than July. We have seen hot Augusts in the past. After a cool June across the Prairies, July turned things around. All major […] Read more

Lots of lightning or nearly continuous thunder is a good indication of a severe storm. As the storm approaches, watch for a green sky and mammatus clouds (clouds that look like bag-like sacks that hang beneath a cloud). These conditions usually indicate the storm contains huge amounts of water and has very strong up and down drafts. | Getty Images

Important to watch skies during storm season

What’s the best way to determine if a storm is capable of producing severe weather? The first thing is to listen to Environment Canada for watches and warnings. It is the only entity allowed to issue watches and warnings in Canada. If a watch is issued, it means the potential exists for severe thunderstorms, but […] Read more

Nearly all straight-line winds, or at least the really damaging ones, occur near the leading edge of a thunderstorm. | David Mehalicz photo

Straight line winds can be very damaging

We know tornadoes can produce the most powerful winds on Earth, and they can be truly awe inspiring to see. Not very many of us will actually experience one because their spatial extent is small. But I can pretty much guarantee that if you live on the Prairies, you will experience a thunderstorm that produces […] Read more


Hail can occur pretty much anywhere across North America, but there are two main regions where chances are significantly higher. The first is the central United States. The second is the Canadian Prairies, Alberta in particular. | Getty Images

Understanding how thunderstorms form hail

If you have spent any significant time on the Prairies, you have probably experienced a hailstorm. Hail can occur pretty much anywhere across North America, but there are two main regions where chances are significantly higher. The first is the central United States. The second is the Canadian Prairies, Alberta in particular. Can it be […] Read more

Like most things in nature, thunderstorms rarely behave like the textbook indicates. Even when all ingredients are there, no storms may form, or sometimes a key ingredient is missing, yet we get a really severe storm.  | File photo

What makes a summer thunderstorm severe?

The Prairies have seen unsettled weather in the last month, including several outbreaks of heavy rain, strong wind, hail and even tornadoes, so it is a perfect time to continue a discussion of thunderstorms. Let’s look at what turns a garden-variety thunderstorm into a severe thunderstorm or even a thunderstorm that you truly remember. Typically, […] Read more