SUDBURY -- Environment Canada expanded its severe thunderstorm watch Tuesday afternoon, adding Greater Sudbury to list of areas in northern Ontario where residents should keep an eye out for some extreme weather.

A warning was issued earlier in the day for Kirkland Lake, Temiskaming Shores, Temagami, Gogama and Foleyet.

"Scattered thunderstorms are expected to move east-southeastward across the regions this afternoon and early evening," Environment Canada said. "Isolated wind gusts of 90 km/h may be associated, along with frequent lightning and small hail."

Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles, the weather forecaster said in a news release. "Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors."

Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could produce one or more of the following: large hail, damaging winds, torrential rainfall.

"The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches," the release said.

As of Wednesday morning, the alert has ended.

To report severe weather, send an email to ONstorm@canada.ca or tweet reports using #ONStorm.