A new study from the University of Calgary suggests that spring weather in southern Alberta has been getting colder over the years — and it’s connected to chinooks. The study, led by John Yackel, a professor of Geography in the Faculty of Arts, found weaker chinook winds are the reason the area that stretches from Calgary to Lethbridge and east towards Medicine Hat has shown a persistent spring cooling trend since 1980. “We are getting fewer winter season chinooks, and when they do occur, they are not as warm as they have been in the past,” Yackel said. Chinooks are generated when Pacific winds that blow west to east hit the Rocky Mountains at an almost 90-degree angle, cooling and releasing precipitation on the western slope before descending and warming on the eastern side. Yackel says the decline in chinooks stems from larger-scale climate changes, and has led to less warming air hitting the southern Alberta region in the winter. In addition, the study indicates more northerly, cold winds are hitting southern Alberta in the same time frame. Yackel says the impacts in southern Alberta include colder temperatures in the winter and spring. In turn, the cooler temperatures lead to an increased snowpack, which affects agriculture, water resources and ecosystems. As the Arctic continues to warm, Yackel says southern Albertans expect to see the pattern of fewer chinooks and the winds being less impactful on temperature increase when they do occur. His study was published in the journal Atmosphere-Ocean on Sept. 1.
