Driving down any one of Alberta’s roads this summer, it would be hard to argue that the dust cloud in the rearview mirror was a bit bigger thank normal — it was dry. Scratch that. It was the driest. Literally.
In all of Edmonton’s recorded weather history, the summer of 2021 has gone down as the driest. Normally the city receives 233mm of precipitation — on average — during the season. According to Environment and Climate Change Canada (ECCC), just 86.3mm fell this summer. That is less than 40 per cent of normal totals. The story around the rest of the province was much the same.
The risk to crops from the abundance of hot and dry weather was in addition to the usual medley of summer storm elements. However, they too were not presenting as normal. The number of storms with hail totalled 96 when on average, Alberta sees 65. Strong winds too were more frequent. An average, summer yields 24 strong wind events, but 35 were recorded in 2021. However, this summer did come in as the fifth-lowest for lightning in the last 20 years.
And then there was the issue of tornadoes, or lack thereof.
“We only had two tornadoes confirmed this year, both of which occurred on June 5”, said ECCC warning preparedness meteorologist Kyle Fougère.
“You do want to have a lot of heat and a lot of humidity for these thunderstorms. We had the heat, but that humidity was really missing and I think that was a big factor.”
Western Canada saw a strong ridge of high pressure sit over it for portions of the summer, which played a role in preventing storm formation, though other forces were at work. Smoke from wildfires in B.C. and Saskatchewan also moved in through July.
Fougère said 2021 saw Alberta experience its second-smokiest summer on record with 125 hours of visibility reduced below 10km because of the haze. He said the record was 230 hours in 2018.
“What that did is it created a layer that prevented the heat to reach the surface, which is a key part of thunderstorm activity, and that really blocked a lot of thunderstorms from forming,” Fougère said.
He added that is was a very unique summer with just how prolonged and extreme the heat was. However, the ridge did divert storms around Western Canada and warmer and drier summers are going to occur more often with a warming climate.