The Labour Day long weekend may begin with severe thunderstorms in parts of southwestern Ontario.
Environment Canada issued a severe thunderstorm watch late Friday afternoon for Sarnia-Lambton, London-Middlesex, Chatham-Kent, Windsor-Essex, Stratford, Southern Perth County, and Northern Huron County.
The national weather agency said a cold front is expected to track east across the region Friday afternoon and evening.
Thunderstorms are expected to develop and may produce heavy rainfall, strong wind gusts of up to 90 kilometres per hour, and small hail.
Heavy downpours may cause water to pool on roadways. There's also the risk of a tornado.
Emergency Management Ontario recommends residents take cover immediately if threatening weather approaches.
*All severe thunderstorm advisories ended late Friday night.