Hail Alley’ receiving more hail than normal this year
| Posted: Thursday, Aug 21, 2014 12:18 pm
According to Bill McMurtry, meteorologist with Environment Canada, Airdrie has had more than its fair share of extreme weather this summer. McMurtry said a number of minor hailstorms moved through the area in July before a massive hailstorm hit the city on Aug. 7, followed by heavy rainfall on Aug. 14.
A series of three hailstorms rolled through Airdrie on the afternoon and evening of Aug. 7, producing golf ball sized hail which damaged many homes and vehicles. The Insurance Bureau of Canada categorized the Aug. 7 hail storm as a “catastrophic event”, which estimates the damage to total more than $25 million.
Airdrie is in the middle of what McMurtry calls ‘Hail Alley,’ a corridor that stretches across west-central Alberta that includes Red Deer to Calgary, however, the number and severity of the storms this year does surprise him.
“When we look at the weather patterns for the summer, (in) the province as a whole it has not been an overly active summer,” he explained. “But when we break it down, there are certain areas that have been. Unfortunately, Airdrie is one of those locations where there’s been several storms that have gone through.”
McMurtry said southern Alberta has not seen as much active weather as it usually does.
As to why Airdrie has been hit by more significant storms this summer, McMurtry said it’s hard to pinpoint.
“Typically, much of Alberta and B.C. have been situated under a upper ridge of high pressure where we’ve had very high temperatures,” he said. “No one knows why (hail has) been so frequent in the Airdrie area, but for some reason it has, and I think it’s almost like a rolling of the dice.”
On the upside, the number of tornadoes seen in Alberta this summer is down, according to McMurtry.
“I think the count (for this year) is about three or four. The closest one (to Airdrie) reported would probably be Gleichen and that was in June,” said McMurtry.
“Typically we’d see around 10 to 12 tornadoes through a summer severe weather season so those numbers are down a little.”
The summer severe weather season goes from roughly mid-May through mid-September, according to McMurtry.
“Each year in the province of Alberta we get about 82 severe weather events per summer severe weather season,” said McMurtry. “That includes tornadoes, thunderstorms that produce 50 millimetres of rain or more per hour, wind gusts equal to or greater than 90 kilometres an hour, and hail that’s nickel size or larger. Over half of those (severe weather events) tend to be hail related.”
McMurtry said although Environment Canada doesn’t keep statistics on humidity patterns, his view is that Airdrie and most of Rocky View County has been “a bit more humid than usual this year.”
Environment Canada has been releasing Humidex numbers for the area throughout July and August. The Humidex is a Canadian invention that reflects how the temperature feels to residents by combining the actual temperature and the humidity to come up with a number. McMurtry called it the summer equivalent of the wind chill factor residents are used to seeing in the winter.
According to McMurtry, the good news is Airdrie and area should soon be in the clear in terms of any more significant hailstorms.
“(Hail) can happen late in the season, and we have seen it happen in the past, but statistically, we are getting towards the end of the summer severe weather season,” he explained.
Historical weather information and severe weather alerts are available on the Environment Canada website at www.weather.gc.ca