A new weather radar system that had its first big test in 2011 when it tracked Hurricane Irene as it approached the North Carolina coast will soon be up and running in the London region. Hank Danizsewski reports.
--- --- ---
Southwestern Ontario will soon get more accurate weather forecasts, thanks to technology installed at Environment Canada’s Exeter radar station.
Since Aug. 17, the station has been shut down while being refitted with new dual-polarization radar.
Environment Canada is slowly converting its network radar stations to the new technology as part of a $107-million program to improve the accuracy of forecasting.
“Dual polarization is the next generation in weather radar. It gives us an extra dimension to give us a better sense of what’s inside the storm cloud,” said Geoff Coulson of Environment Canada.
While the radar station was out of service for the upgrade, Environment Canada relied on a composite radar image compiled from signals from nearby radar stations in Canada and the United States.
Coulson said the Exeter site is back in operation for Environment Canada forecasters, but the public website for the station will still carry the composite image for at least another week.
--- --- ---
Exeter radar station
- Located about eight kilometres east of Exeter.
- One of 31 radar stations across Canada.
- Serves all Southwestern Ontario. Next nearest Environment Canada station is in King City, north of Toronto.
- About 20 years ago the station was converted to Doppler radar, which bounces a microwave signal, allowing forecasters to estimate intensity and velocity of approaching precipitation.
--- --- ---
- A refinement of Doppler radar that scans an approaching weather front both horizontally and vertically. Conventional Doppler sends out a horizontal burst of micowaves for a one-dimensional image.
- Dual system gives a more accurate measure of rainfall amount and allows forecasters to measure droplet size so they can distinguish between rain, hail and snow.
- System can also pick up airborne tornado debris — allowing forecasters to confirm a tornado is on the ground.
- System had its first big test in 2011, when it was used to track Hurricane Irene as it approached the North Carolina coast.