Volatile Alberta summer weather has kept the hail mitigators busy.
Weather Modification Inc., based in Olds, has sent cloud seeding planes to 58 storm cells between High River and Lacombe since storm season started on June 1, in an effort to decrease the size of ice stones.
The team was, in fact, busy in Central Alberta just last week.
Planes were dispatched over both Rocky Mountain House and Sundre on July 21 and hours were spent seeding northeast of Olds, between Innisfail and Red Deer, and southwest of Sylvan Lake on July 22.
“Especially compared to last year — last year was a very slow year — this year is much busier,” said Tom Walton, field program manager.
He added historical data shows 2010 has been on par with the storm season average, although activity may be slightly higher than normal.
“Mother Nature is just looking at us differently,” he reasoned for the difference between the years.
Weather Modification Inc., a program funded by a consortium of insurance firms, has been seeding clouds to minimize the size of hail for the past 15 years, in an effort to decrease the amount of storm damaged caused in Southern Alberta urban areas.
The program targets its energies and resources on the most populated centres, such as Calgary and Red Deer, while tending to smaller municipalities on a secondary basis.Three staff meteorologists in Olds monitor weather systems and produce daily detailed forecasts that highlight potential storms.
Four planes — two out of Red Deer and two out of Calgary — can be called on to seed clouds around the perimeter of a hailstorm with silver iodide.
“It’s not hail elimination, it’s hail minimization,” Walton explained.
He also stressed that the use of silver iodide does not have any adverse effects on the environment as they use a “minute quantity” that is thinly distributed during the course of the flight, which at times can last for more than three hours. David Wray, a meteorologist with Environment Canada, said storm activity in Central and Southern Alberta this year has not been overly extreme but is definitely greater than the past few quiet years.
“This year, because of the moist spring, there does happen to be a lot more moisture in the lower levels of the atmosphere, which is required for severe weather, especially for the more severe storms that produce funnel clouds and hail,” he said.
“There has been a greater abundance of that this year throughout all the Prairies actually.”
As there is still a lot of moisture in the boundary layer, Wray expects the region will continue to see activity throughout the rest of the summer.
Storm season typically tapers off by mid-September.
The Alberta foothills face more thunderstorm days than any other region in the Prairies, although Wray said activity in this region tends to be weaker than what is experienced in southern Saskatchewan, southern Manitoba and into Ontario.