A severe thunderstorm watch is in effect for parts of the Superior North region.
Environment Canada issued the advisory on Friday for a large swath of Northwestern Ontario, which includes the Lake Nipigon and Armstrong areas.
The advisory warns that conditions are favourable for the development of severe thunderstorms that could produce strong winds and large hail.
Wind gusts of up to 90 kilometres per hour are possible, along with quarter-sized hail.
"Large hail can damage property and cause injury," the advisory reads. "Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles."
Storms are expected to become more widespread through the afternoon, with the risk of severe thunderstorms lessening into the evening.