Environment Canada launching new radar software to deal with wind turbines
Published Monday, August 11, 2014 5:19PM EDT Last Updated Monday, August 11, 2014 6:07PM EDT
Two weeks after a tornado hit, the cleanup continues for many residents in Grand Bend.
Residents had roughly 30 minutes warning of the arrival of the storm that levelled over 8,000 trees.
Bill Weber, mayor of the Municipality of Lambton Shores, says, "Proper warning is key to keeping people safe when bad weather approaches. We can't stop the storm but we can get people out of the way of the storm."
It's the radar at the Exeter Weather Station that helped predict that storm - and all weather within 250 kilometres of it.
But the impending arrival of hundreds of wind turbines may put the Exeter Weather Station's predictions in jeopardy - while the radar can block stationary objects - it cannot block out the spinning blades of wind turbines.
On its website Environment Canada says the degradation of data interrupted by wind turbines can be "significantly misleading for forecasters under storm conditions."
Jim Young works at Environment Canada’s national radar program and says the national weather service has been concerned about wind farm clutter for years.
The agency uses Doppler radar to predict storms, but the movement of wind turbine propellers can mimic weather.
Young said accurate radar data relies on movement, with still objects like buildings, trees and towers filtered out to allow for an analysis of the weather, and the disruption caused by wind farms is based on their proximity to radar sites.
"The closer you get, that clutter becomes larger and larger," he said.
In extreme circumstances, wind turbines can block radar scans, which Young compares to light from a flashlight.
"If you put a large obstruction in front of your flashlight, you are going to create a shadow behind it, where you can't see anything," he said, adding that the same thing can happen when scanning wind farms.
He said so far Environment Canada hasn't had to deal with full blockages, "Environment Canada will be very concerned if any wind farms are built that close to a radar site."
With severe weather seemingly the new normal, seconds count when bad weather approaches - just ask the people of Goderich, who will never forget their 2011 twister.
Deb Shewfelt, mayor of Goderich, says "We only had about 10 minutes warning of our F3 tornado and people are worried now because the weird weather we're having - it appears any storm can blow up [into] a tornado and I think Grand Bend was a good example of this."
Environment Canada and NextEra Energy Canada - the owner of the turbines that could cause the Exeter Radar problems - are talking about switching turbines off during extreme weather, one of many mitigation factors currently under negotiation.
Meteorologists are hoping their research into a new radar technology may also help.
As for the folks in Grand Bend, they hope Environment Canada figures something out - before the next big storm hits.
Weber says "We count on Environment Canada to know what's coming and be able to warn people as soon as possible. Safety is number one."
And Young says that other types of radar in Canada, such as air surveillance and air traffic control, could also be affected by wind turbines.
"It's not a problem limited to Canada...It's a worldwide issue."
With files from Clare Clancy at The Canadian Press