The prairies were not home to many tornadic thunderstorms this year, so students who enrolled in the University of Manitoba's storm chasing course had to make their way to the United States.
University of Manitoba's storm-chasing course was a thundering success even though no tornadoes were spotted, according to instructor John Hanesiak. “We were on two tornado-warned storms on two different days, but they just refused to drop tornadoes.”
And while students' eyes gazed upon the eye of the storms in the U.S., the number of tornado sightings on the Canadian Prairies was well below normal -16 in total this year when there is normally about 46. Manitoba typically sees 10 tornadoes during the summer, but 2009 had 4 relatively weak ones. "Dauphin had a major hail storm, as did Winnipeg, but when it comes to severe weather this year in general, it just simply wasn't around much." said Hanesiak.
There is a simple explanation that goes with this, though: Mother Nature's
dose of cold weather in July and August made for too cool conditions, lower humidity, and a more south-bound jet stream contributing to less tornadic storm activity over much of the prairies.
"A thunderstorm is created by warm air rising and condensing into a cumulus
cloud, and if enough energy is available and released, it can grow rapidly into a major storm" said Hanesiak. "If the right wind shear exists, the storm can develop into a supercell storm that separates its upward air flow into the storm (updraft) from its downward moving air (downdraft) that is accompanied by heavy rain, damaging winds and sometimes hail at the ground" – its these supercell storms that the storm chasing team chases.
“A tornado can also be produced by these supercells that can range in size, strength and length of time on the ground.” says Hanesiak. “We still do not fully understand why some supercells produce tornadoes and others do not.” It is estimated that only 5-10% of all supercells produce tornadoes.
Hanesiak says, however, their storm chasing course in the United States was
a bit of a different story when it comes to low numbers of stormy weather – the U.S. saw a normal year in terms of tormadic storms.
"On our six day trip, where we went as far as Kansas, students were exposed
to different storms on every day, and one where we even questioned how safe the storm
"On one particular stop, the sky darkened, and the class could see the
storm approaching," Hanesiak said. "We managed to stay in the vans and keep
everyone safe from extreme lightning … something that always looms in all of these storms."
Students on the trip took advantage of ThreatNet, a new device which uses XM
satellite radio to track storms.
"Along with our GPS unit, ThreatNet tells us where we are in relation to the storm in real-time.” said Hanesiak. “It's a brilliant tool that we are happy to offer to the students of the course."
Though it was long days in the vans traveling – 5500 km in 6 days, Hanesiak said all of the students fully enjoyed themselves.
"We drove through nine states, and saw some of the most spectacular storms.
We were all very impressed."