Environment Canada says the London region can expect to see freezing rain this weekend.
A Freezing Rain Warning is in effect for London, Middlesex County, Elgin County, and Oxford County.
The weather agency says a potentially historic ice storm that may cause widespread power outages is expected this weekend.
"A moisture laden low pressure area over the Central Plains States will amble towards the lower Great Lakes this weekend," the warning says. "As the low approaches, brisk northeasterly winds will pump in cold Arctic air, forcing temperatures below freezing this morning."
Environment Canada says patchy rain will become widespread Saturday morning then change to freezing rain. The rain will likely persist into Saturday evening.
A lull in precipitation is likely Saturday evening with patchy freezing drizzle expected. However, the freezing rain will likely become widespread again and continue into Sunday before changing to rain. Significant rainfall on Sunday may cause localized flooding.
Ice is expected to build up to 25mm across the region by Sunday morning.
Strong winds will likely gust up to 70 or 80km/h Saturday night and Sunday. The combination of excessive ice accumulations and strong winds will likely result in widespread power outages due to fallen trees and power lines.
Dangerous winter driving conditions are expected throughout the weekend.
Public Safety Canada advises residents to stay away from fallen power lines and make an emergency kit with drinking water, food, medicine, a first-aid kit, and a flashlight.
This warning will be updated as necessary.
