Are we facing a warm, wet summer?

The almanacs are calling for a warmer- and drier-than-average July

A battleground between cool and warm air masses led to the storms that unloaded on western Manitoba as the calendar changed from June to July.

What a month June turned out to be — and for many of you, it was really not a good month. It’s time to take a break from our usual weather programming and stop to look back at last month’s weather, then see what the different weather prognosticators say about the rest of the summer.

Those of you who follow my weather column would know I don’t try to compete with news reporters when it comes to weather events. I let them dig up the details of local weather stories and report on those; I’m just not good at that. What I am good at is looking at the big weather picture, then trying to explain just what the heck is going on. So, I am not going to go into any details on some of the big rain and thunderstorm events that have been pounding different parts of the Prairies over the last week or two, but I will give a brief explanation of what’s going on before we look back at the June numbers and peer ahead for what July and August might have in store for us.

Convective conditions

Over the last month we have gone in and out of a blocking pattern known as an omega block. It is called this because the setup in this pattern has the jet stream diving southward over western North America, then curving and heading northward over central/eastern North America, before curving and diving back southward across far eastern North America. So, if you were to picture this in your mind’s eye, the jet stream would make an omega symbol (Ω). Across the west (Alberta), cool low pressure dominates, while across the eastern Prairies, hot, dry weather tends to win out. In between these two air masses we can often see a battleground with thunderstorms dominating at this time of the year.

With this in mind, looking back at June’s weather numbers, we find temperatures across Alberta were near to slightly cooler than average, but precipitation was way above average, ranging from 90 mm in Peace River to over 172 mm in Calgary. As we move east into Saskatchewan, Saskatoon felt the impact of the Alberta lows as they moved off to the northeast. That city recorded below-average temperatures in June along with nearly 110 mm of rainfall — over 40 mm above the long-term average. Farther south, Regina missed out on the Alberta lows and was just on the edge of the eastern battleground. It recorded a mean monthly temperature right around average, but saw precipitation amounts only about half of the long-term average.

On to Manitoba. Early in the month, eastern regions saw heavy thunderstorms that brought flooding rains. Then the heat and humidity built in toward the end of the month. The battleground then set up over western Manitoba, where training thunderstorms over a couple of nights brought over 200 mm of rainfall to some regions. Overall, it was a warmer-than-average month across agricultural Manitoba, with temperatures ranging from 1 to almost 2 C warmer than average. Precipitation was also above average for most regions, except for a strip running from Winnipeg to just east of Brandon and down to the border.

Trying to summarize the month of June across the Prairies in just a few words is next to impossible. It was cool and wet across the west and northwest; dry with average temperatures across south-central regions; and over the east, warm with either dry, average or extremely wet conditions. Oh, the power of convective precipitation!

Who called it?

Looking back at the different forecasts, it’s not surprising that with June’s weather being all over the map, that none of the forecasts got it all right. One thing: if I had to give the nod to one forecast, it would be the Canadian Farmers’ Almanac, with a call of above-average precipitation and near-average temperatures with a hot end to the month.

OK, now on to the latest long-range forecasts. The Old Farmer’s Almanac calls for slightly warmer-than-average temperatures with slightly below-average precipitation in July, followed by a cool and wet August. The Canadian Farmers’ Almanac looks like it is calling for a warmer- and drier-than-average July followed by near-average temperatures and near- to slightly above-average rainfall in August.

When we look at the main weather models, the CanSIPS model calls for near- to above-average temperatures across the eastern Prairies in July with below-average temperatures over western regions. It also calls for above-average precipitation. August is forecast to have near- to slightly below-average temperatures along with near- to slightly above-average rainfall. The CFS model calls for above-average temperatures in July, especially over eastern regions, with near- to above-average rainfall. Its August forecast is for near- to slightly above-average temperatures and precipitation.

Finally, my throw at the long-range weather dartboard: I am leaning toward the CanSIPS model, with above-average temperatures in July over eastern regions and near- to slightly below-average temperatures over western regions along with near- to above-average rainfall. I am going to deviate for August, going with near- to slightly above-average temperatures right across the Prairies, with near-average rainfall. Now let us see just what Mother Nature throws at us this summer.

About the author

Co-operator contributor

Daniel Bezte

Daniel Bezte is a teacher by profession with a BA (Hon.) in geography, specializing in climatology, from the U of W. He operates a computerized weather station near Birds Hill Park.



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