The new tornado alley
By Mark Ferguson, On Campus News
October 9, 2012, 10:40 am
The climate is changing around Saskatchewan, and as a result, tornado warnings were unusually frequent in the summer of 2012 with more recorded touchdowns than any year on record. Many photographers and filmmakers kept an eye on the sky in the hope of capturing a monster in the new Tornado Alley.
Environment Canada reports that Saskatchewan had more recorded tornadoes in July than the entire U.S., so storm chasers from around the world have made their way here. These individuals would not have considered the province a hot spot a few years ago, as only around 13 tornadoes touched down annually, but this year has been different with 30 tornadoes recorded by Environment Canada, including eight in one day – June 15.
According to the National Center for Atmospheric Research in the U.S., tornadoes need four ingredients to form: warm humid air near the surface, colder air above, a strong variation of winds, and a fast-moving storm front. Saskatchewan, it seems, has been a mixing bowl for these key ingredients and scientists say this is not typical.
The biggest change in the climate is in the amount of water falling. Over the past two years, average rainfall has increased from 250 to 650 millimetres around Saskatoon and some areas of the province are even wetter. Flooding has quickly become a growing concern. With more water near the surface of the land and with hotter temperatures, tornado sightings are becoming more frequent.
“This kind of activity is very unusual in Saskatchewan,” said John Pomeroy, Canada Research Chair in Water Resources and Climate Change. “With the increased precipitation and
heat, the province has become a peak place for tornado activity.”
The amount of water sitting near the surface is something Pomeroy has not seen in 20 years of research. Vast flood plains have blocked major highways the past two springs and for Pomeroy, driving across the prairies is a different experience than it was when he started studying climate change.
“There is a totally different hydrology in the province now. We see more rainfall in the spring and more multi-day rainfalls throughout the year,” Pomeroy said.
The heavy rainfall in the province is a result of moisture moving up from the Gulf of Mexico through the U.S. and up to the Canadian prairies, he explained. But while areas further south like the Tornado Alley of Kansas and Oklahoma are recording some of the driest summers on record, parts of Western Canada are becoming more humid, ideal environments for the types
of storms that produce tornadoes.
Tornadoes are just one result of the increased humidity, and Pomeroy worries the real threat is not just storms, but extreme weather, both wet and dry, which will have profound implications for agricultural practices and food production. Corn crops, for example, are failing in regions around Kansas because of the extreme drought, whereas in Saskatchewan, the climate is becoming increasingly favourable to growing corn. And like tornadoes, many crops need more heat and moisture, and Saskatchewan will need to adapt accordingly.
“Weather is changing rapidly and we are experiencing a warming trend that the Earth has not seen since the Ice Age,” Pomeroy said.